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This paper focuses on both brake safety and ride comfort improvement in the postbraking phase. First, a complete vehicle model is established together with the design of a safety control strategy for the longitudinal deceleration control method. Information on driver behavior and vehicle signals is collected to ensure braking safety, including vehicle speed, vehicle deceleration, steering wheel angle, accelerator opening degree, and ABS status. Second, a methodology for longitudinal deceleration control is proposed using a sliding mode control algorithm, aiming to improve ride comfort in the postbraking phase under the prerequisite of a reduced braking distance. Finally, co-simulation, based on Simulink and CarSim, and vehicle tests are carried out. The results show that when the braking distance is constant, the longitudinal deceleration vibration and vertical pitch vibration in the postbraking phase are well suppressed. The peak overshot of longitudinal deceleration and the amplitude of vertical vibration in the postbraking phase decrease. The vibration period of the vehicle is shortened. The braking process of the vehicle is smoother. Thus, the ride comfort is improved in the postbraking phase while maintaining braking safety.

In case of emergency braking in danger, autonomous vehicle usually uses electronic stability control system to maintain the dynamic stability of the vehicle, and by adjusting the steering system, the vehicle can realize autonomous driving. However, when the autonomous vehicle is in emergency braking on the split‐mu road, due to the inconsistent adhesion coefficient on both sides of the road, the inconsistency of tire force will not only damage the dynamic stability, but also make the vehicle deviate from the planned trajectory. Because the path tracking algorithm of autonomous vehicle needs to detect the trajectory error first, it will lead to the time delay of trajectory error correction, and its correction ability will weaken with the decrease of speed, so that the vehicle's trajectory will deviate unilaterally. Thus, the tracking accuracy is reduced and the driving safety is endangered. This paper proposes a dynamic coordinated control strategy based on dynamics and kinematics. In response to the rapid changes in lateral disturbances, a flexible control transfer mechanism based on vehicle status is constructed, realize dynamic coordinated control based on path tracking algorithm and active steering algorithm. While improving the lateral stability, the trajectory error is reduced.

Keeping a vehicle in its current lane without veering into adjacent lanes is important in hard-braking manoeuvres on split- μ roads. Whether the emergency braking is initiated by a human driver or ...

This paper proposes a hybrid suspension system, consisting of a linear electric motor (LM) and a semi-active mono-tubed magnetorheological damper (MRFD), to improve vehicle dynamics with lower powe...

Aircraft ground braking control is a complex time-varying dynamic problem, especially when there are unexpected disturbances from lateral wind or visual error. Therefore, under some extreme conditions, it is hard for the pilot to control aircraft braking as well as usual without assistant control. This paper solves this problem by proposing a novel assistant control for aircraft ground braking, mainly based on the pilot control model and the LPV theory. And in order to reflect the control characteristics of the pilot, the sensory and control-theoretic model were combined together for controller designing. To test the performance of proposed control method, a real time pilot-in-loop simulation system is constructed. According to experiment results, the proposed assistant control shows better performance than pilot control, for it not only help the pilot to resist disturbance, but also hardly run counter to the pilot’s intent.

In this paper we used the braking load index to illustrate the different braking load of cities under different braking conditions. The initial speed of braking, braking process speed difference, braking deceleration, temperature change of friction plate in braking process, the brake pedal force are different. Through the analysis of the measurement data, we comprehensively understood the differences of the braking conditions in different cities and the driving habits of consumers in different regions. The research could give a good theoretical support for the design process and after sales service.

Multi-speed transmissions with 2–3 speed are considered to be an effective and compact equipment for pure electric vehicles’ (PEV) dynamic and economical improvement. However, the characteristics of fewer gears and larger speed ratio gap not only request uninterrupted shifting quality but also smooth pedalpower pattern to derive demand power of motor from drivers’ input. Due to these features of multi-speed transmissions for PEV, using one fixed pedal-power pattern in conventional ways will cause output torque shock after shifting or force drivers to passively adjust the pedal for constant acceleration. A speed-based unified pedal-power pattern (SUPP) is proposed to interpret the demand power of motor according to the vehicle speed instead of motor speed. The SUPP contains three components including a base, a feedforward and a feedback part to satisfied the different dynamic request under different gears and different speed. Furthermore, the SUPP is integrated with the innovative clutch-to-clutch shifting algorithm which achieves uninterrupted shifting on PEV, and realizes in optimal trajectory of motor operating points during and after shifting. A case study of SUPP is conducted with a two-speed transmission for PEV through both simulation and experiments. The simulation and experimental results prove that the SUPP is able to obtain uninterrupted wheel torque during and after shifting with constant drivers’ intention, and prevent drivers from unnecessary adaptation.

The steer-by-wire (SBW) system eliminates the mechanical connection between the steering wheel and the carriage wheel. It eliminates various limitations of the traditional steering system, so that the steering ratio of the car can be freely designed and the steering by wire system can achieve good active front wheel steering (AFS) function. In the study of the stability control of vehicles on the μ-split road, there are mainly two methods, one based on vehicle trajectory maintenance and the other based on vehicle dynamic stability control. Both of these control methods have delays, which is not conducive to the trajectory flowing ability of the vehicle when driving on the μ-split road. A shared control strategy is proposed to improve the vehicle’s stability. The purpose of this study is to establish different variable transmission ratio characteristic curves according to the different input signals of the driver and the vehicle, such as angular change speed, steering wheel angle, etc. Based on these conditions, a new model combining driver’s intention with vehicle dynamic model is established, so as to achieve the purpose of judging the stability of vehicle in advance, to reduce the delay time of control and to improve the response speed, which will improve the stability performance of the vehicle.

During the emergency braking process on the split-[Formula: see text] road, the lateral stability of the vehicle is poor, and the intervention of ABS will cause corresponding lateral disturbance. It is difficult for the driver to control the vehicle accurately. Especially at the end of the braking process, due to the withdrawal of ABS, the increase in braking pressure causes the longitudinal force of the tires on both sides to be inconsistent, which reduces the stability of the vehicle at this time. This paper proposed a shared control strategy to solve the related problems. First, a segmented active steering strategy is used in the driver’s intention optimization algorithm to optimize the driver’s actions in time at the initial stage of the braking process and to optimize the lateral stability of the vehicle by tracking the estimated tire slip angle at the end of the braking process. Then, according to the path envelope based on the driver’s path error neglecting feature and the dynamic state of the vehicle, a flexible control transfer mechanism is established. The trajectory following algorithm based on linear quadratic regulator is used to correct the driver’s intention optimization algorithm according to the flexible control transfer mechanism.

In this paper we researched the vehicle braking sense in three aspects of human, vehicle and environment and analysed their impacts on brake feeling. Through the real vehicle test we analysed the relationship among pedal force, pedal travel and deceleration. We used dynamometer test method to study the brake noise question. We designed a fixture which could imitate the suspension and made the test more close to the true level. Moreover we discussed how to establish the evaluation system of vehicle braking condition. Through real vehicle test of braking, we can test and record the brake system parameters in the braking process under urban working conditions. We recorded the brake frequency, the change of brake speed and brake disc temperature. Meanwhile, based on the analysis of braking condition, we put forward the index of brake load to reflect the city’s traffic conditions. Experiment show that the braking condition and brake feel are related, braking condition also provides theoretical support for the design of brake system.