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Path tracking is critical for agricultural vehicles to achieve autonomous operation and to improve operational efficiency and accuracy. This study aims to address the high-precision path tracking requirements for the tracked vehicle GY-8. An improved pure pursuit path tracking control method is proposed to enhance the performance of path tracking. For the GY-8 vehicle's single-sided braking and steering approach, a dual-wheel differential kinematic model is established. A smooth steering method using PWM (Pulse Width Modulation) is designed to reduce the likelihood of deviation from the predetermined path due to PWM braking steering. A method based on the theory of circular arc similarity is introduced to determine the path curvature and segmentation. The NSGA-II optimisation algorithm is employed to optimise and obtain the optimal look-ahead distance for different curvature segments, thereby enhancing the accuracy of path tracking. The improved algorithm was experimentally validated for path tracking on paved surfaces. In the experiments, the improved algorithm demonstrated average error, maximum error, error standard deviation, and Fréchet distance of 0.0266 m, 0.0973 m, 0.0195 m, and 0.0891 m, respectively. This represents a 15.6%, 25.8%, 4.9%, and 27.6% improvement over the pure tracking algorithm. When applying the improved pure tracking algorithm to path tracking in agricultural orchard soil environments, the results indicated maximum error, average error, and error standard deviation of 0.1272 m, 0.0351 m, and 0.0215 m, respectively. The overall findings suggest that the improved method significantly enhances the accuracy of path tracking, providing theoretical support for advancing navigation technology in tracked vehicles. • An improved path tracking control approach proposed. • Circular arc similarity method determines curvature of each path segment. • NSGA-II optimizes look-ahead distance for varying curvatures. • Experimental results show that the algorithm performs satisfactorily. [ABSTRACT FROM AUTHOR]

• The Riccati transformations for track subsystems are obtained by a novel dynamic recursive method. • Dynamic modeling of tracked vehicles using both the overall transfer equation and the recurrence relations. • Dynamic modeling considers the nonlinear characteristics of track systems and magnetorheological dampers. • Compared with passive suspension, magnetorheological semi-active suspension improves the tracked vehicle performance. The magnetorheological technology has been widely used in automotive applications, whereas less research has been done on tracked vehicles. Hence, this research focuses on the dynamic modeling of the whole system of a tracked vehicle, for analyzing the effect of magnetorheological semi-active suspension on track tension and chassis vibration during driving. Applying the multibody system transfer matrix method and a dynamic recursive method, the dynamic models of the chassis subsystem and the double track subsystems are developed, respectively. These three subsystems are coupled by nonlinear contact forces, where the meshing shock, polygon effect, and rolling effect during contact are also taken into consideration. Subsequently, the normalized Bouc-Wen model is adopted to describe the nonlinear characteristics of rotary magnetorheological dampers. Then, a semi-active suspension control of the tracked vehicle is implemented with rotary magnetorheological dampers and the independent skyhook control method. Finally, numerical simulations are performed under different operating conditions. Comparing with the case of passive suspension, it reveals that, the magnetorheological semi-active suspension not only improves the distribution of the track tension but also effectively reduces the chassis vibration. It provides a theoretical basis for the design and application of magnetorheological semi-active suspensions for tracked vehicles. [ABSTRACT FROM AUTHOR]

Tracked vehicles are widely deployed for heavy lifting and transportation on inaccessible terrains such as swamps, bogs, and peatlands. The stability of a tracked vehicle is traditionally assessed only under uniaxial loading conditions and the impact of combined loading from different directions is ignored. This makes the conventional design framework somewhat unreliable. The failure envelope approach has been widely employed to assess the load-carrying capacity of shallow foundations. However, the failure envelopes available in public domain mainly focused on single isolated foundations, ignoring the interference effect between the tracks due to the rigid connection of the vehicle. This paper aims to develop an integrated framework to assess the stability of a tracked vehicle on a soft soil under fully three-dimensional loading conditions. The finite element method is adopted to simulate the soil–vehicle interactions, with the tracks idealised as two shallow foundations in parallel. The stability of the foundation system is described in terms of failure envelopes considering various track configurations and load combinations. Failure envelopes are represented by expressions and ultimately integrated into a multiple-nested function to determine the overall stability factor. The framework is demonstrated by a case study of designing a tracked vehicle under combined loading conditions. [ABSTRACT FROM AUTHOR]

• 193 full-scale tests of tracked vehicles in a progressive slip condition reported. • Parabolic trends were found between DBP versus slip and torque versus slip. • Trends between STMN versus DBP, traction, and torque were influenced by slip. • A modest parabolic trend between sinkage and CP/CI ratio was discovered. In 2013, an extensive effort began to create a consolidated off-road vehicle mobility database named DROVE (Database Records for Off-road Vehicle Environments). DROVE consists of over 8,500 experimental test records measured over several decades for wheeled and tracked vehicles over various terrains. This paper introduces the third release of DROVE, which adds results from 193 tests primarily consisting of data for tracked vehicles on fine-grained soils in a progressive slip condition. Performance parameters considered in DROVE 3.0 include drawbar pull, torque, sinkage, and traction. These parameters were compared to mobility numerics, such as soil-track mobility number, contact pressure to cone index ratio, and mean maximum pressure. These parameters were used to develop mobility trends in this paper. DROVE is intended to be a resource for the mobility community applicable to many situations, including evaluating and advancing numerical simulations, improving closed-form algorithms, and understanding vehicular trends that can be used for development or purchase specifications. [ABSTRACT FROM AUTHOR]

Introduction/purpose: The paper presents a systematic approach to the development of a series hybrid electric tracked vehicle (HETV) including powertrain sizing and adequate energy management strategy (EMS) selection. Methods: Powertrain elements were sized considering key performance requirements. Three energy management strategies were proposed: Thermostat Control Strategy (TCS), Power Follower Control Strategy (PFCS), and Optimal Power Source Strategy (OPSS). The evaluation of the powertrain configuration and the three proposed EMSs was performed in the Simulink environment using a driving cycle containing significant acceleration, braking and steering. Results: The results showed that the OPSS proved to be the best due to increased fuel economy and a low battery state of charge (SOC) variation. Compared to the previous research of the same vehicle with a parallel hybrid configuration, significantly better results were achieved. The investigation of the results indicates that the proposed powertrain and control strategy offer 53.79% better fuel economy which indicates that the powertrain sizing was properly performed. Conclusions: The results of this work are of great importance for understanding the effect of proper powertrain sizing on fuel economy. Compared to the reference vehicle, the proposed configuration achieves significant improvement, most of which is attributed to adequate sizing. The OPSS proved to be the best strategy, thus confirming the theoretical hypothesis. The series hybrid configuration with the OPSS as the EMS proved to be a major candidate for use in HETVs. [ABSTRACT FROM AUTHOR]

Tracked vehicles are widely used as seabed production tools to ensure a stable motion on soft sediments. However, the slippage resulted from the complex nonlinear track-terrain interaction while trajectory tracking causes problems for precisely predicting the motion. Accordingly, a "proper" motion control method is necessitated. This work proposes a novel dynamic modeling approach and motion control method for seabed tracked vehicles under nonholonomic constraints, with the inclusion of the effects of the bulldozing resistance, compaction resistance, water resistance, and the direction and velocity of the current. The back-stepping control based on a model-based proportional-integral-derivative three degrees-of-freedom method is applied in the controller, and its stability is proven by Lyapunov theory. The effectiveness and accuracy of the method in controlling seabed tracked vehicles are validated by simulation examples. [ABSTRACT FROM AUTHOR]

It has been shown that tangential inlet return cyclones are commonly used for inlet air filtration of off-road vehicle engines. The wear of the engine elements, and thus their durability, is determined by the efficiency and accuracy of the inlet air filtration. It has been shown that the possibilities of increasing the separation efficiency or decreasing the pressure drop of a cyclone by changing the main dimensions of the cyclone are limited, because any arbitrary change in one of the dimensions of an already operating cyclone may cause the opposite effect. A literature analysis of the possibility of increasing the filtration efficiency of cyclones by modifying the design of selected cyclone components was conducted. In this paper, three modifications of the cyclone design with a tangential inlet of the inlet air filter of a military tracked vehicle were proposed and performed. The symmetrical inlet of the cyclone was replaced with an asymmetrical inlet. The cylindrical outlet tube was replaced with a conical tube, and the edges of the inlet opening were given an additional streamlined shape. The modification process was carried out on three specimens of the reversible cyclone with a tangential inlet. After each modification, an experimental evaluation of the modifications was carried out. The influence of the modifications on the cyclone's efficiency characteristics and pressure drop was examined. Subsequent modifications of the cyclone were performed on the same specimen without removing the previous modifications. Tests were performed in the air flow range QG = 5–30 m3/h. Polydisperse "fine" test dust with grain size dpmax = 80 µm was used for testing. The dust concentration at the cyclone inlet was set at 1 g/m2. The performed modifications caused a slight (about 1%) increase in separation efficiency in the range of small (up to QG = 22 m3/h) flux values and about 30% decrease in pressure drop in the whole range of the QG flux, which positively influences the increase in engine filling and its power. There was a noticeable increase in filtration accuracy in the range of low and high values of QG flux, which results in a decrease in the wear of engine components, especially the piston-piston ring-cylinder (P-PR-C) association, and an increase in their durability. [ABSTRACT FROM AUTHOR]

In this paper, we describe a prototypical crawler vehicle developed for "Hairo Sozo Robocon," i.e., the 4th creative robot contest for decommissioning conducted in 2019. The rules of this robot contest required a high turning ability on a flat floor and high mobility through the inner space of a pipe. In addition, the robot needed to salvage objects from a floor placed 3.2 meters underneath itself. We developed a multi-articulated tracked vehicle to provide high mobility in both contexts. The vehicle was equipped with a sensorless salvaging bucket inspired by a traditional sampler sounding weight. [ABSTRACT FROM AUTHOR]

In order to make the tracked transport vehicle more suitable for wetland operation, the physical and mechanical properties of wetland soil and the driving resistance, buoyancy and steering performance of the vehicle were analyzed. According to the actual demand, the chassis of LF352 the actual demand was improved. The virtual prototype of the vehicle was built using Creo and RecurDyn software, and the wetland ground parameters were set. The multi-body dynamics simulation analysis of the tracked wetland transport vehicle was carried out, and the prototype was put into the wetland for field test. The simulation results showed that the vehicle had better tension and dynamic performance when the preload of the track was 22 kN. When the vehicle ran straight, the stability of the low speed gear was the best, and the subsidence was far less than the minimum clearance of the vehicle. The vehicle turned under full load, using one or two gear steering the most stable. The field test of the prototype test showed that the transport vehicle can safely carry out uniform and variable speed movement in the wetland. By comparing and analyzing the test results, it was concluded that the error was within the acceptable range, which indicated that the design of tracked transport vehicles suitable for wetland operation was feasible, and provided theoretical basis and technical support for the subsequent manufacturing of tracked transport vehicles. [ABSTRACT FROM AUTHOR]

Omnidirectional mobility is a popular method of moving in narrow spaces. In particular, the planar omnidirectional crawler previously developed by the authors can traverse unstable and uneven terrain with a large contact area. A novel point is that the proposed system is unique in its ability to carry heavy loads in all directions without getting stuck because of the large pressure-receiving area between the crawler and the ground. This work will facilitate omnidirectional motion, which has important implications for the use of robots in spaces such as not only factories, distribution centers, and warehouses but also soft soil in disaster sites. The objective of the present study was to establish a design and control method for an omnidirectional crawler mechanism that can conduct holonomic and two-axis cross-driving. Only two motors are set on the crawler base for translation in the X- and Y-directions, and two large crawler units are arranged for turning. We design a small crawler that has higher traversing ability with a derailment prevention mechanism and tapered track. Further, the relationship between the motor rotational speed as input and crawler velocity as output was verified for control. In addition, it was demonstrated experimentally that the proposed crawler could travel across various types of rough terrain in a target direction. [ABSTRACT FROM AUTHOR]

• Mobility codes do not accurately represent modern military mobility on organic soil. • Low ground pressure vehicles perform better on organic soil. • Organic soils have a wide variability of soil and vegetation conditions. Current political climates have generated a renewed interest in the northern regions of the world. These areas are known to have soft marshy peat, highly organic soils, and harsh winter climates. Current capabilities for vehicle mobility modeling on this terrain is limited and existing studies do not include contemporary military vehicles. This work presents mobility experiments of modern military vehicles at multiple field sites containing peat or highly organic soils that can be used to improve mobility modeling on these soils. Field experiments are being conducted during multiple seasons, including winter, spring, and summer. The vehicle traction, motion resistance, and hard surface rolling resistance of an instrumented High Mobility Multipurpose Wheeled Vehicle (HMMWV) and a Small Unit Support Vehicle (SUSV) were examined. The first is a common multi-purpose vehicle and the second is a vehicle designed to operate in these types of environments. This data set will provide the basis for model development and validation for vehicle mobility in highly organic soils. [ABSTRACT FROM AUTHOR]

This paper presents a novel alternate multibody model for a tracked vehicle by replacing the tracks with a set of imaginary wheels. A planar multibody model with imaginary wheels replacing tracks is developed with a nonlinear contact force model for the interaction between the wheel and ground for both hard and soft terrains. The results of the proposed track model are validated with experimental data from the literature as well as with the results from a detailed track model in Adams tracked vehicle software. The paper demonstrates that replacing the tracks with imaginary wheels provides a simple yet realistic alternate model for tracks. The computational cost is reduced significantly and hence one can use this to carry out detailed vehicle performance studies before finalising a design. [ABSTRACT FROM AUTHOR]

• The paper presents a simple, reliable and fast dynamics model of off-road track vehicle. • The numerical model was formulated by a new method – DBD (Discrete Body Dynamics). • The proposed method was demonstrated using an M113 track vehicle. • The time computation of the new code was faster compared with that obtained from commercial Multi-Body Dynamic programs. • The method is simple enough to be used in prediction of trafficability for off-road applications. The paper presents a simple, fast, and reliable dynamic model for an off-road track vehicle operating on terrain with obstacles. The method has been proven previously for wheeled-vehicle formulation. The model is based on a discrete body dynamics (DBD) method, which leads to simplistic linear decoupled motion equations. In this method, joints and bodies with relatively small mass are replaced with stiff springs and dampers, eliminating the system's constraints and reducing the number of system bodies; this is important for accelerating the simulation runtime of the track vehicle model. The track in this approach is based on modeling each link as a point-mass. Two consecutive links are connected by stiff springs and dampers. This approach reduces the calculation time and increases system stability. The track–soil interaction was modeled using Bekker's and Janosi's formulation (Bekker, 1956; Hanamoto and Janosi, 1961). Specific soil properties were obtained for each link–soil interaction from soil classification and GIS. The link–ground contact was determined from topographic surface and adjustment of the force and direction acting on the track. The results of the simulation using the DBD method were compared with Siemens' VL commercial multibody dynamics program and with experiments reported in the literature. Results using the proposed method were found to be similar to the commercial program based on published experiments. The solution runtimes obtained for unpaved soil were two orders faster with the DBD method compared with the Siemens' VL program. The model was written as an independent software infrastructure, enabling easy integration with any other software component, such as a control system. The algorithm is in a suitable form for parallel processing calculation to speed up the runtime simulation close to real-time. [ABSTRACT FROM AUTHOR]

Track assemblies are widely used to reduce vehicles' ground pressure and improve their off-road performance. During off-road, the track tension has a significant effect on the performance of the crawler driving system. Previous control strategies only make use of the motions of partial road wheels. This paper develops a logical improvement to govern the motion of the track tensioner by using all road wheels. First, a dynamic model of the hydraulic-mechanism coupling system is established using the transfer matrix method for multibody systems and pressure-flow equations. Then, in order to get the angle of the idler arm, a modeling method of wheel envelope perimeter is developed, which is based on the locations of all wheels. Simulation results indicate that the control system maintains the wheel envelope perimeter almost constant while road wheels swing and decrease the possibility of peel-off and breakage of the track. It alleviates the track repeated stretch and keeps the tension in a stable range to reduce the fatigue damage. The control strategy can effectively reduce the peak value of the upper track tension during a vehicle passing through obstacles. This study suggests that the active track tensioning system can be implemented to improve the driving properties of tracked vehicles. [ABSTRACT FROM AUTHOR]

• An improved Riccati transfer matrix method for closed-loop systems is developed. • A spatial dynamics model for a tracked vehicle is established. • Two simplified contact models between the sprocket, track and rollers are proposed. • The effect of the track pre-tension on the transversal vibration of upper track is analyzed. In order to analyze the effect of track pre-tension on the transversal vibration of the upper track, a multibody dynamics model of a tracked vehicle needs to be established. In view of the complex structure of tracked vehicles, the computational efficiency of conventional methods cannot meet engineering design requirements. In this paper, the Riccati Transfer Matrix Method for nonlinear closed-loop multibody systems is proposed and applied to the modeling and simulation of tracked vehicle systems. It avoids the overall dynamic equations of the system and achieves efficient computation with a smaller matrix scale. By selecting accelerations and forces as elements of the state vectors instead of coordinates and forces, linearization is avoided. The track chain is cut in a revolute joint. Its effect on the closed-loop system is represented by a set of constraint equations and internal constraint forces. An improved Riccati transformation for closed-loop systems is proposed to connect the internal force and acceleration parts in the state vector with the system constraint internal forces. The track pre-tension can be adjusted by moving the position of the idler relative to the chassis. The root mean square of vertical acceleration of mid-span with respect to the chassis is selected to evaluate the transversal vibration of the upper track. Simulation of a tracked vehicle driving on different road conditions is carried out with different idler displacements. Finally, a reasonable adjustment strategy for the track tensioner is proposed corresponding to different running conditions. [ABSTRACT FROM AUTHOR]

• The derivation of dynamic equation for a mechanical-electrical-hydraulic coupling tracked vehicle system. • A DOB-based hybrid controller is developed to keep the driving force constant. • The application of constant driving force control strategy to control the dynamic track tension. Track tension has a significant impact on the dynamic performance of a track. Maintaining the stability of track tension is conducive to improving the service life of track, meanwhile reducing the risk of peel-off and breakage. The tensioner can adjust the track tension by moving the idler to tighten or loosen the track. However, during the off-road operation, the conventional tensioner is locked, which makes it impossible to adjust the tightness of track in time. The purpose of this paper is to propose a constant hydraulic driving force control method for track vehicles in the driving process. Specifically, for an electro-hydraulic force servo system, the driving force is adjusted in real time and kept constant by a hybrid controller based on a disturbance observer. The dynamic equation of a tracked vehicle is established using transfer matrix method for multibody systems (MSTMM). The control performance is evaluated by the dynamical model together with the analytical model for the electro-hydraulic system. Numerical simulation shows that with the same pre-tension, the average value of dynamic track tension with the tensioner controlled is effectively reduced, and is significantly lower than that with the tensioner locked. Moreover, the stability of track is improved due to the reduced variation range of dynamic tension and track perimeter. [ABSTRACT FROM AUTHOR]

An energy management system based on off-road condition prediction is designed for the energy management of hybrid tracked vehicle in off-road environment. The vehicle speed and attitude are measured by using the vehicular sensor, and the off-road condition is classified based on support vector machine. A speed prediction model based on Markov chain is established using historical driving speed and acceleration for different off-road conditions. A model predictive control strategy based on off-road condition prediction is designed for energy management of hybrid electric tracked vehicle. The simulated results show that the proposed energy management system can be used to achieve the control objectives and improve the performance of hybrid electric tracked vehicles in off-road environment. [ABSTRACT FROM AUTHOR]

• A new release of DROVE with additional 294 test records from tracked vehicles on fine-grained soils. • The database includes drawbar pull, motion resistance, sinkage, torque, trim angle, and slip. • The database was used to evaluate Vehicle Terrain Interaction (VTI) algorithms. With over 8000 field and laboratory tests, the Database for Off-Road Vehicle Environments (DROVE) provides a consolidated database of parameters for the assessment of tracked and wheeled vehicles on fine- and coarse-grained soils. This paper presents a new release of DROVE, version 2.0, which adds 294 results from the test performed by powered and unpowered tracks on fine-grained soils. Several performance parameters including drawbar pull, motion resistance, sinkage, torque, trim angle, and slip were measured alongside track geometry and loads. Soil properties were quantified via cone index testing, allowing performance parameters to be assessed in terms of their relationship to contact pressure divided by cone index. Potentially useful relationships were identified for drawbar pull, sinkage, and powered torque. The new release of DROVE dataset can be used for several applications including evaluation of existing mobility models, development of improved algorithms, and validation of numerical simulations for tracked vehicles. [ABSTRACT FROM AUTHOR]

Ｉｎ ｏｒｄｅｒ ｔｏ ｉｍｐｒｏｖｅ ｔｒａｃｋｅｄ ｖｅｈｉｃｌｅｓ’ ａｄａｐｔａｂｉｌｉｔｙ ｔｏ ｄｉｆｆｅｒｅｎｔ ｔｙｐｅｓ ｏｆ ｒｏａｄ ｓｕｒｆａｃｅｓꎬ ａ ｄｙｎａｍｉｃ ｓｉｍｕｌａｔｉｏｎ ｍｏｄｅｌ ｏｆ ｔｒａｃｋｅｄ ｖｅｈｉｃｌｅｓ ａｎｄ ｖａｒｉｏｕｓ ｔｙｐｅｓ ｏｆ ｒｏａｄ ｗａｓ ｅｓｔａｂｌｉｓｈｅｄ ｂａｓｅｄ ｏｎ ｔｈｅ ｍｕｌｔｉ-ｂｏｄｙ ｓｉｍｕｌａｔｉｏｎ ｐｌａｔｆｏｒｍ. Ｔｈｅ ｔｉｍｅ-ｄｏｍａｉｎ ｄｙｎａｍｉｃ ｒｅｓｐｏｎｓｅ ｓｉｇｎａｌｓ ｏｆ ｖｅｈｉｃｌｅ ｃｅｎｔｒｏｉｄ ｗｅｒｅ ｃｏｌｌｅｃｔｅｄ ｔｈｒｏｕｇｈ ｔｈｅ ｄｒｉｖｉｎｇ ｓｉｍｕｌａｔｉｏｎ ｏｆ ｔｒａｃｋｅｄ ｖｅｈｉｃｌｅｓ ａｎｄ ｒｏａｄ ｍｏｄｅｌｓꎬ ａｎｄ ｔｈｅ ｓｉｇｎａｌｓ ｗｅｒｅ ｄｅｃｏｍｐｏｓｅｄ ｂｙ ｗａｖｅｌｅｔ ｔｒａｎｓｆｏｒｍａｔｉｏｎ. Ｄｉｓｔａｎｃｅ ｅｖａｌｕａｔｉｏｎ ｔｅｃｈｎｉｑｕｅ ｗａｓ ｕｓｅｄ ｔｏ ｅｘｔｒａｃｔ ｓｅｎｓｉｔｉｖｅ ｆｅａｔｕｒｅ ｖｅｃｔｏｒｓ. Ａ ｒｏａｄ ｉｄｅｎｔｉｆｉｃａｔｉｏｎ ｍｅｔｈｏｄ ｂａｓｅｄ ｏｎ ｔｈｅ ａｂｏｖｅ ｓｅｎｓｉｔｉｖｅ ｆｅａｔｕｒｅ ｖｅｃｔｏｒｓ ｗａｓ ｐｒｏｐｏｓｅｄ ｂｙ ｕｓｉｎｇ ＢＰ ｎｅｕｒａｌ ｎｅｔｗｏｒｋ. Ｉｎ ｏｒｄｅｒ ｔｏ ｖｅｒｉｆｙ ｔｈｅ ｖａｌｉｄｉｔｙ ｏｆ ｔｈｅ ｍｅｔｈｏｄꎬ ａ ｔｅｓｔ ｓｙｓｔｅｍ ｂａｓｅｄ ｏｎ ｓｍａｌｌ ｔｒａｃｋｅｄ ｖｅｈｉｃｌｅ ｍｏｄｅｌｓ ｗａｓ ｂｕｉｌｔ. Ｔｈｅ ｖｅｈｉｃｌｅ ｍｏｄｅｌ ｄｒｉｖｅｄ ｏｎ ｔｈｅ ａｃｔｕａｌ ｒｏａｄ ｔｏ ｃｏｌｌｅｃｔ ｔｈｅ ｔｉｍｅ-ｄｏｍａｉｎ ｄｙｎａｍｉｃ ｒｅｓｐｏｎｓｅ ｓｉｇｎａｌｓ ｏｆ ｔｒａｃｋｅｄ ｖｅｈｉｃｌｅｓ′ ｂｏｄｙ ｃｅｎｔｒｏｉｄꎬ ｌｏａｄ ｗｈｅｅｌｓ ａｎｄ ｔｒａｃｋ-ｔｅｒｒａｉｎ ｉｎｔｅｒａｃｔｉｏｎ. Ｔｈｅ ｒｅｓｕｌｔｓ ｓｈｏｗｅｄ ｔｈａｔ ｔｈｅ ｉｄｅｎｔｉｆｉｃａｔｉｏｎ ｐｒｅｃｉｓｉｏｎ ｏｆ ｔｈｅ ｍｅｔｈｏｄ ｉｓ ９９％ . Ｔｈｉｓ ｍｅｔｈｏｄ ｈａｓ ａ ｈｉｇｈ ｉｄｅｎｔｉｃｉａｔｉｏｎ ａｂｉｌｉｔｙ ｆｏｒ ｒｏａｄ ｔｙｐｅｓ. [ABSTRACT FROM AUTHOR]

The electric drive tracked vehicle has good motion controllability, and the problems of heavy load and short life of brake system for the traditional tracked vehicle can be relieved by means of electric brake, which is an ideal driving method for realizing the unmanned driving of tracked vehicle. Through the design of braking system for an electric drive unmanned tracked vehicle, a complete technical solution for the electro-mechanical combined braking system is proposed, which is totally controlled by wire. An improved three-stage mechanical-electric brake combination method is adopted, and according to the principle of maximizing braking energy recovery under the premise of ensuring the custom dynamic performance, a corresponding mechanical-electrical braking force distribution strategy is given. After the platform was built according to the scheme, the brake performance test was carried out. The test results show that the system has good braking performance and stability, and can fully meet the requirements of the national military standard for the braking performance of military tracked vehicles while ensuring the kinetic energy conversion efficiency being around 25%. [ABSTRACT FROM AUTHOR]

An algorithm combining the driving force statistical prediction model and the vehicle dynamics model is established to estimate the ground parameters based on the experimental data of independent electric tracked vehicles. The path is segmented according to the deviation point of zero course angle, and the Gaussian mixture model (GMM) is used for the multivariate clustering of path segments. The clustering tags of three consecutive path segments are used to represent the types of motion primitive; the data is grouped based on the types of motion primitive, and then GMM is used to build a statistical prediction model. When the ground parameters are estimated, the driving wheel torques are predicted by calling the driving force statistical prediction model and using the Gaussian mixture regression (GMR) after the primitive type is determined. The nonlinear least squares method is used to minimize the errors of the predicted torque values from the statistical prediction model and the theoretical torque values characterized by a kinetic equation, thereby gaining the estimated values of ground parameters. The test values of ground parameters are obtained by processing the data collected from real vehicles compared with the estimated values. The results show that the proposed method can be used to guarantee the precision of predicted results and the overall efficiency of the algorithm on the premise that fewer sensors are used. [ABSTRACT FROM AUTHOR]

In order to reveal the mapping relationship between internal excitation and vibration characteristics of planetary transmission mechanism, a vibration acceleration measurement system of planetary transmission mechanism was established by designing a vibration test scheme, and the vibration characteristics of typical gearshift 2 500 r/min planetary transmission mechanism were measured and analyzed. The results show that the vibration root mean square (RMS) value of planetary transmission mechanism is correlated with the position of measuring point. The measuring point is in the meshing position of planetary gear, and its vibration amplitude is larger. The vibration RMS value increases with the increase in the torque. The frequency spectrum analysis results show that the vibration energy mainly concentrates on the meshing frequency and multiple frequencies of planetary gears, and the axial frequency spectrum is similar to the radial frequency spectrum. The maximum amplitude of meshing vibration is obtained by measuring the vibration of planetary transmission mechanism and analyzing its frequency spectrum. [ABSTRACT FROM AUTHOR]

This paper proposes a model predictive control (MPC) algorithm for trajectory tracking of vehicles. Using MPC can reduce tracking errors and random disturbances in complex environments in time. According to the linear kinematics model of the vehicle, a kinematics trajectory tracking controller and an electromechanical coupling dynamics trajectory tracking controller are designed. The drive system of the electrically driven tracked vehicle is non-linear, and an electromagnetic system and mechanical system interact with each other. Taking the electromechanical coupling characteristics into consideration can ensure the matching of the electromechanical performance and the stability of the system during the trajectory tracking control. To verify the algorithm, kinematic simulations and dynamic simulations are performed. The simulation results show that the algorithm has good tracking ability. In addition, a set of test devices is designed to confirm the performance of the trajectory-tracking control algorithm in a real environment. Vision recognition is used to obtain vehicle deviation, and the Kalman filter is used to reduce signal interference. The result shows that the algorithm can meet trajectory tracking requirements. [ABSTRACT FROM AUTHOR]

A series of models， including a dynamics model, a driving system model and a braking system model， were established to study a tracked vehicle, which are used to predict the energy/force distributions of the braking system in high speed tracked vehicle. An approach to define testing road using eight parameters such as line length, slope, radius, roil angle, pavement power spectral density, running resistance coefficient, maximum soil adhension coefficient, and maximum steering resistance coefficient, is proposed, and then the influences of these parameters on the speed of vehicle are investigated. A driving strategy to minimize the running time of vehicle is designed based on the optimal control theory, and a binary linear regression equation used to calculate the braking torque is derived statistically. The accuracy of the approach and the efficiency of the strategy are verified using the experimental and simulated results. A typical model is built based on the experimental data of 1 000 km distance field test, and is used to predict the energy/force distributions of braking system in the region of a whole distance of 6 000 km. [ABSTRACT FROM AUTHOR]

Abstract Tracked vehicles have inherent advantages over wheeled vehicles, as the former provide stable locomotion on loose and uneven terrain. However, compared with the latter, the slippage generated due to the complex, nonlinear track-terrain interactions during skid-steering to follow a curve, brings about difficulties preventing the accurate prediction of their motions. The key to improving the accuracy of trajectory-following is the "proper" motion control methodology that can accurately factor-in the slippage behavior. In this paper, the authors propose a novel approach to the dynamic modeling and motion control of tracked vehicles undergoing skid-steering on horizontal, hard terrain, under nonholonomic constraints. Due to the skew-symmetry property of nonholonomic mechanical systems, the control methodology is established using the backstepping method based on a modified Proportional–Integral–Derivative (PID) computed-torque control. A key element in the control strategy proposed here is the reliable estimation of the pose – position and orientation – of the vehicle platform and its twist—point velocity and angular velocity. It is assumed that the vehicle is suitably instrumented to allow for accurate-enough pose and twist estimates. Validated via a numerical example, the proposed controller is proven to be effective in controlling an unmanned tracked vehicle. Highlights • A novel motion controller for nonholonomic tracked vehicles is proposed. • The skew-symmetry property is validated to be feasible for nonholonomic mechanical systems. • The control methodology is based on a modified PID computed-torque controller integrated with backstepping method. • Vehicle pose and twist is estimated using a novel biaxial accelerometer strapdown. • Nonlinear terrain-track interactions for different working environments are modeled. [ABSTRACT FROM AUTHOR]

Highlights • The relationships of major factors with the deformation of soil were discussed. • A new method deducing pressure–sinkage of tracked vehicle were proposed. • Water content and repeated loading are considered in the method. • The prediction results showed good agreement with the experimental results. Abstract Tracked vehicles assume an important role in engineering and agriculture. Supporting-trafficability is the lifeline of tracked vehicles. The terrain characteristics is concerned with the relationships critical in defining the mobility of tracked vehicles. Conventional terramechanics models cannot accurately describe the relationship between tracks and soil. A major problem is that these models do not account for the water content in the soil and sinkage speed. Water content is an important factor affecting sinkage of vehicles, which in turn affects vehicles' driving resistance. Increased driving resistance is a barrier to the mobility of an tracked vehicle. Considering sinkage speed is conducive to describe the trafficability of tracked vehicle moving at high speed. In this paper, the terrain characteristics to describe the relationship of the pressure/sinkage of four common soil types in Southwest China were measured using soil bin tests. We discuss characteristics like high sinkage speed, water content variation, and repeated loading, as well as the relationships of these major factors with the deformation of soil. We present a method to deduce the pressure-sinkage relationship for track shoes using the stress-displacement relationship model proposed by Bekker. The described method advances the study and understanding of track-terrain interaction in complex environments. [ABSTRACT FROM AUTHOR]

A longitudinal and lateral joint path following coordinated control method based on double-layer driver model is proposed to solve the path following control problem of tracked vehicle with clutch and brake steering structure. The first layer of driver model is based on the Gaussian mixture model and hidden Markov model. The desired path is taken as an input. The aim is to predict the steering mode sequences and switch the control mode according to the sequences. The second layer of driver model is established by using the fuzzy logic to reflect the skilled driver’s longitudinal and lateral operation experience. The longitudinal and lateral control commands are calculated according to the desired deviation of course. The results show that the driving experience can be utilized effectively to settle a challenge due to longitudinal and lateral combined vehicle dynamic characteristic and steering uncertainty in the proposed control method. The lateral control accuracy is less than 1.0 m under the particular scenario. [ABSTRACT FROM AUTHOR]

This paper tries to figure out the fatigue damage of transmission shaft of transmission system caused by the engagement of main clutch under typical operating conditions, and then analyze the main factors causing the fatigue damage of transmission system. A dynamic model of vehicle starting is built to obtain the relationship between the vehicle transmission system load and the engagement displacement value of main clutch. A testing platform of tracked vehicle is built to get the test data of transmission system under typical operating conditions. The dynamic tests of stepper engagement of main clutch are designed to collect the torque data transmitted by the transmission system in the process of main clutch engagement. Finally, the rain-flow counting method and rain-flow filtering method are used to process the original data, and then the linear fatigue, cumulative damage theory is used to calculate the fatigue damage of transmission shall in transmission system to determine the engaging stale of main clutch when the rnaxi-mum fatigue damage is caused to the transmission system. The results show that the displacement point at which the axial moving speed of the driven plate, changes the most is the danger point when the maximum fatigue damage is caused lo the transmission shaft, which is accounted for 73. 86% of the total damage, and the damage degree is 2. 87 times of the main clutch fully synchronized state. [ABSTRACT FROM AUTHOR]

Single rigid body models are often used for fast simulation of tracked vehicle dynamics on soft soils. Modeling of soil-track interaction forces is the key modeling aspect here. Accuracy of the soil-track interaction model depends on calculation of soil deformation in track contact patch and modeling of soil resistive response to this deformation. An algorithmic method to calculate soft soil deformation at points in track contact patch, during spatial motion simulation using single body models of tracked vehicles, is discussed here. Improved calculations of shear displacement distribution in the track contact patch compared to existing methods, and realistically modeling plastically deformable nature of soil in the sinkage direction in single body modeling of tracked vehicle, are the novel contributions of this paper. Results of spatial motion simulation from a single body model using the proposed method and from a higher degree of freedom multibody model are compared for motion over flat and uneven terrains. Single body modeling of tracked vehicle using the proposed method affords quicker results with sufficient accuracy when compared to those obtained from the multibody model. [ABSTRACT FROM AUTHOR]

In this paper, a complete mathematical model for a half-tracked vehicle with eight degrees of freedom is established. It is difficult to control a suspension system owing to complexity of system itself and irregular excitations from road surfaces. A road excitation model is analyzed in which a relationship between the vehicle body and the gun is taken into account. Active disturbance rejection controllers are proposed in all channels of six independent subsystems by decoupling the original system. With switch extended state observers, total disturbances are eliminated for the half-tracked vehicle. Simulation results are presented to illustrate effectiveness of the proposed method in this paper. [ABSTRACT FROM PUBLISHER]

This article deals with the experimental verification of the power requirements of the tracked vehicle power unit while driving on a flat terrain. Requirements are based on results of a dynamic simulation. At first, the article presents the description of the simulation model, including the virtual terrain, on which the vehicle was moved. Second, a description of the experiment performed directly on the real prototype is presented. Measured variables were flow rates and pressures in the hydraulic system, whereby the power transmission from the engine to drive sprockets of four tracked undercarriages is ensured. Finally, there is the comparison of the calculated and measured time-power characteristics. The results correspond to each other. [ABSTRACT FROM AUTHOR]

This paper presents a high-fidelity, general, and modular method for lateral dynamics simulation of high-speed tracked vehicle. Based on classic terramechanics, a novel nonlinear track terrain model is derived. The track terrain model meets the needs of longitudinal and steering motions, comprehensive track slips, and modular modeling for tracked vehicles with various configurations. The proposed lateral dynamics model is in reasonably agreement with the available experimental data. Using the lateral dynamics model, the main factors (normal pressure distribution, position of gravity center, and ratio of track-ground contact length and tread L / B ) effecting the steady state characteristics of skid steering are discussed. The normal pressure distribution is idealized as trapezoid and dual trapezoid distribution to reflect same common driving situation. The under-steer parameter is introduced in this paper to quantitatively evaluate the steady-state characteristics of skid steering for tracked vehicle. The results show that the ratio of theoretical speed difference and average speed of both side tracks Δ u / u as the steering input is more suitable for the high-speed tracked vehicle. The vehicle with dual trapezoid normal pressure distribution slightly tending to localize in the middle of track or with slightly rearward position of gravity center has better handling stability characteristics. [ABSTRACT FROM AUTHOR]

This study presents a new general transient contact and slip model for tracked vehicles on hard ground which is simple, accurate, and in agreement with the test results to a satisfactory level. Simulating zero track speed instances become possible with the new contact/shear model which is the major proposed improvement in addition to more accurate results for transient steering and tractive inputs. The model represents a general tracked vehicle having rear or front sprockets, with parameters for center of gravity, wheel positions, number of wheels, and track-pretention. To calculate longitudinal and lateral forces, a transient shear model is used. Shear stress under each track pad is assumed to be a function of shear displacement. The contact time formulation used in shear displacement calculation is improved to gain accuracy for transient and zero track speed conditions. The model is implemented on the Matlab/Simulink platform and verified with a comprehensive program of road tests composed of transient steering and tractive/braking scenarios. The results of the simulations and the road tests are satisfactorily similar for both constant and transient input maneuvers. Moreover, sensitivity simulations for vehicle parameters are conducted to show that the model responses are inline with the expected vehicle dynamics behaviours. [ABSTRACT FROM AUTHOR]

The Polish Armed Forces use tracked vehicles that serve as a core element of the ground combat forces. These vehicles are capable of fighting in all kinds of terrain conditions, in any season of the year. Combat missions are often fought in areas where even no dirt roads are available. The present paper assesses the reliability of tracked vehicles in the context of their irregular operation, as well as service- and maintenance-related vulnerability. [ABSTRACT FROM AUTHOR]

One of the most important components of a high speed tracked vehicle is an efficient suspension system. The vehicle should be able to operate both in rough terrain for performance of engineering tasks as well as on the road with high speed. This is especially important for an autonomous platform that operates either with or without human supervision, so that the vibration level can rise compared to a manned vehicle. In this case critical electronic and electric parts must be protected to ensure the reliability of the vehicle. The paper presents a dynamic parameters determination methodology of suspension system for an autonomous high speed tracked platform with total weight of about 5 tonnes and hybrid propulsion system. Common among tracked vehicles suspension solutions and cost-efficient, the torsion-bar system was chosen. One of the most important issues was determining optimal track tensioning - in this case an active hydraulic system was applied. The selection of system parameters was performed with using numerical model based on multi-body dynamic approach. The results of numerical analysis were used to define parameters of active tensioning control system setup. LMS Virtual.Lab Motion was used for multi-body dynamics numerical calculation and Matlab/SIMULINK for control system simulation. [ABSTRACT FROM AUTHOR]

This study explored the feasibility of using the Radau pseudospectral method (RPM) to optimize the energy management strategy for a hybrid tracked vehicle. The engine–generator set and the battery pack of the serial hybrid tracked vehicle were modeled and validated through the bench test. A DC-DC converter was equipped between the battery pack and the DC bus in this hybrid powertrain, which increased the flexibility of energy distribution between the engine–generator set and the battery. It was simplified as a voltage regulator in the hybrid powertrain model. The power demand during the vehicle operation was calculated according to the vehicle dynamics and driving schedules. The optimal control problem was formulated to minimize the fuel consumption through regulating the power distribution properly between the engine–generator set and battery pack during a typical driving schedule. The RPM was applied to transform the optimal control problem to a finite-dimensional constrained nonlinear programming problem. A comparison of the solutions from RPM and dynamic programming showed that the former offers the higher computation efficiency and better fuel economy. [ABSTRACT FROM AUTHOR]

In order to realize the unmanned driving of tracked vehicle, its future motion trajectory within a period of time should be accurately predicted in trajectory planning. It is difficult to predict the future motion trajectory of vehicle due to the slippage between tracks and ground. A kinematics model based on the instantaneous steering center is developed by studying the interaction of track and ground. The relative pose of vehicle is a function of the slippage parameters, and the Jacobi matrix is difficult to solve. For this problem, the analytical solutions of Jacobi matrix are deduced by linearizoffing the functional differential equations. Slippage parameters are solved iteratively using Levenberg-Marquardt method according to the calculated and measured pose errors, and a set of input commands is given to predict the future motion trajectory within a period of time. The proposed method is used to update the slip parameters in real time without prior knowledge of terrain parameters. The real vehicle tests show that the position errors predicted using this method are reduced by more than 30% compared to the traditional trajectory prediction method. [ABSTRACT FROM AUTHOR]

A coordinated hierarchy control strategy of driving torque is proposed for the distributed electric drive tracked vehicle. The coordination control system structure is developed, which is divided into motion control layer, control allocation layer and anti-slip layer. The vehicle is considered to be an unequal over-actuated system. A master-slave multi-motor control allocation law is established. The quadratic programming method is used to design the torque optimization distribution law of in-wheel motors, and the weighted least square (WLS) method is used to solve torque distribution , which could improve adhesion margin and decrease friction loss between motor wheels and track. The anti-slip control law developed by LADRC is used to enhance the adhesive force by restricting the slip of drive wheel. Co-simulation of Matlab and RecurDyn shows that the control allocation could realize torque optimization distribution, and LADRC anti-slip controller could regulate the slip speed in steady margin, which could improve the stability and efficiency of force transfer. [ABSTRACT FROM AUTHOR]

In order to study the steady-state steering performances of tracked vehicle under concentrated load and improve the simulating accuracy of tracked vehicle steering model, the effect of track tension on ground pressure distribution is analyzed, and a computation model of ground pressure distribution of tracked vehicle is proposed. A new steering dynamics model is derived to establish a corresponding dynamics equation set based on shear stress and shear displacement relationships of track and ground. The effect of ground pressure change induced by track width and tension on steady-state steering kinematics and dynamics parameters is analyzed. The analysis result is verified through vehicle test. The test results show that the theoretically calculated result is well fitted with the test data, and the proposed model is proven to be effective. [ABSTRACT FROM AUTHOR]

In this paper, the torque and power required by dual motors for electric tracked vehicle during dynamic steering maneuvers with different steering radiuses are analyzed. A steering coupling drive system composed of a new type of center steering motor, two Electromagnetic (EM) clutches, two planetary gear couplers, and two propulsion motors is proposed for the dual motors drive high speed electric tracked vehicle (2MHETV), which aims to improve its lateral stability. An average torque direct distribution control strategy based on steering coupling and an optimization-distribution-based close-loop control strategy are designed separately to control the driving torque or regenerative braking torque of two propulsion motors for vehicle stability enhancement. Then models of the 2MHETV and the proposed control strategy are established in Recudyn and Matlab/Simulink respectively to evaluate the lateral stability of dynamic steering for the 2MHETV with different steering radiuses on hard pavement.The simulation results show that the lateral stability of the 2MHETV can be significantly improved by the proposed optimization-distribution-based close-loop control strategy based on steering coupling system. [ABSTRACT FROM AUTHOR]

In order to improve the load disturbance rejection and rotating speed control effect for the tracked vehicle engine, a feedforward-feedback speed control algorithm is proposed according to the torque-based architecture. A load estimation algorithm is designed based on mean value model and crankshaft dynamic model. The estimation accuracy of the proposed load estimation algorithm is validated under steady and transient conditions. The feedforward-feedback speed control algorithm can significantly improve the capability of load disturbance rejection in the simulation of powertrain. The reseach results show that a rapid speed control effect can be achieved and repetitive calibration of speed control parameters can be avoided during acceleration process of tracked vehicle. The improvement in pedal-rotating speed following characteristics leads to the reduction in unexpected gear shifting of tracked vehicle in a driving cycle. [ABSTRACT FROM AUTHOR]

The steer resistance of tracked vehicle has character of nonlinear and wide range change, and the drive system is very likely to be saturated dual to large vehicle inertia and constrained drive torque, while the drive motors of dual-motor tracked vehicle are independent with each other, which leads to regulate the drive torque per side to realize stable steer. In order to improve the stability of steer, the sliding mode technique with conditional integrator is applied to yaw rate control. A velocity-yaw rate steer control structure is developed through dynamics analysis. The equivalent conditional integral sliding mode control（ECISMC） algorithm is designed，which could increase the response speed through equivalent term feed-forward compensation and adopt the robust and rapid discontinuous nature of the sliding control outside boundary layer, enabling smooth transition to a PI control law with anti-windup inside boundary layer to eliminate track error by the conditional integrator approach. Co-simulation of Matlab and RecurDyn shows that the control algorithm has advantages of high precision, robust to disturbance, anti-windup and smooth control input, which could realize stable steer performance. [ABSTRACT FROM AUTHOR]

For the complex problems of ground-track-wheels coupling system excitation characteristics， a dynamics model of the tracked vehicle suspension system was established leaving out the track impacts. The theoretical calculations of the road wheels dynamic displacement were realized through kinetic equation. It was then simulated under various working conditions. A multi-body dynamics simulation model was proposed. Comparing the simulation result with that of the theoretical calculations， the change regulation of the road wheels dynamic displacement with the vehicle speed was analyzed. The results provide a theoretical reference for designing and developing the tracked vehicle. A technical support for loading excitation directly on road wheels about vehicle road simulation system is provided as well. [ABSTRACT FROM AUTHOR]

Steel and rubber are two kinds of materials which are often used for the tracks of off-road vehicles. The objective of this study was to compare tractive performances of steel and rubber grouser shoes under different soil moisture contents. In this study, the tractive performance of single grouser shoe was predicted by soil parameters and three-dimensional shearing model. The soil used in this study was clay soil, and ten different soil moisture contents ranged from 8.58% to 54.36% were applied for investigation of soil parameters. For each soil moisture content, the penetration test, direct shearing test, density and soil moisture content measurement have been performed to obtain the required soil parameters. The experimental results showed that thrust and running resistance of steel single grouser shoe had similar trends to those of rubber single grouser shoe. The thrust of rubber single grouser shoe was always greater than that of steel single grouser shoe with the increase of soil moisture content, and as well as the running resistance. However, the traction of rubber single grouser shoe had a different trend to that of steel single grouser shoe. The traction of steel single grouser shoe was always greater than that of rubber single grouser shoe at any given moisture content except at the stage of less than 15% moisture content. From the experimental results, it can be concluded that the steel single grouser shoe performed better than rubber single grouser shoe in traction for the soil used in this study. [ABSTRACT FROM AUTHOR]

Steering dynamic model of double motor coupling drive transmission for tracked vehicle has the features of MIMO, parameter-uncertainty and nonlinearity. The steering system is transformed into a forward speed control subsystem and a steering speed control subsystem by dynamic decoupling control algorithm. For the forward speed control subsystem, a robustness sliding mode control algorithm is proposed to converge the speed errors based on the desired speed and the current speed. For the steering speed control subsystem, a steering speed control algorithm is designed based on the fuzzy adaptive sliding-mode algorithm to ensure the tracking control of the reference steering speed. The steering tracking control is verified by real-time simulation system. The results show that the proposed control algorithm is effective. [ABSTRACT FROM AUTHOR]

For the tracked HEV, a new preheating system of powertrain is designed to solve the cold start problem in winter, in which the heat is generated by the drive motor running at very low speed. The new preheating system can meet the need of cold start. In order to get the heat from the power cabin to the outside environment, CFD numerical calculation is done for the heating process. The simulation results are verified through the relevant test. Based on the heat loss of power cabin and the parameters of engine cabin components, a heat transfer model of preheating system is established by using MATLAB. The total energy required for preheating at different ambient temperatures is calculated by this model. The energy losses and heating efficiency are obtained at different heating powers. The results show that the minimum heating power is 70 kW, and total energy isl81 MJ. By considering the low temperature discharge rule of power battery, the heating power and battery capacity in the process of preheating are calculated for lithium iron phosphate batteries. The minimum battery capacity is 292 A.h. [ABSTRACT FROM AUTHOR]

The driving cycle of tracked vehicle is so complex, and the drive motor with wide speed range runs under nonlinear, uncertain and strong coupling load. How to control the motor speed to improve the stability of steering has become a research hot point. An electric differential control strategy is put forward. And the LADRC control algorithm is used in speed control of PMSM system, and LESO is used to estimate and compensate the unknown disturbance, thus rejecting the disturbance and improving the dynamic performance of system. The collaborative model of Matlab and RecurDyn softwares and test bench are built. The simulation and experimental results show that the speed control strategy with LADRC can be used to achieve rapid response without overshoot, strong disturbance rejection and good parameter a-daptability, which improve the vehicle stability. [ABSTRACT FROM AUTHOR]

This is a theoretical investigation into the effect of various suspension configurations on a tracked vehicle performance over bump terrains. The model developed is validated using published experimental data of the modal characteristics of the vehicle. The desired performance is based on ride comfort via the mixed objective function (MOF), which combines the crest factor of bounce acceleration, bounce displacement, angular acceleration, and pitch angle. The optimisation process involves evaluating the MOF for different numbers and locations of dampers and under different rigid bump road conditions and speeds. The system responses of the selected suspension configurations in the time and frequency domains are compared against the undamped suspension. The results show that the suspension configurations have a significant effect on the vehicle mobility over bump road profiles. For a five-road–wheel half model of a tracked vehicle, the maximum number of dampers to use for ride comfort over these road bumps is three with the dampers located at wheel positions 1, 2 and 5. This confirms the current practice for many tracked vehicles with 10 road wheels. However, it is further shown that the suspension fitted with two dampers at the extreme road wheels offer the best performance over various rigid bump terrains. [ABSTRACT FROM AUTHOR]