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This study presents a theoretical framework for defining the performance level of wireless safety functions within industrial environments. While acknowledging the simplifications inherent in our approach—primarily based on packet loss rates as a measure of system performance—the study underscores the dynamic challenges posed by real-world warehouses. Through an in situ measurement study of a forklift truck safety system, we validate the proposed method and emphasize the need for a more nuanced examination of wireless communication in complex settings. The study advocates for an expanded theoretical framework that considers fluctuations in warehouse dynamics, accounting for their impact on packet loss rates and, consequently, the precision of performance-level assessments. Furthermore, the research highlights the complexity introduced by wireless system characteristics not addressed in the simplified model, urging future investigations to incorporate these factors for a comprehensive understanding of wireless safety systems. The absence of specific criteria for wireless systems within existing standards emphasizes the necessity for a specialized framework in addressing safety aspects unique to wireless applications. [ABSTRACT FROM AUTHOR]

Lack of situation awareness (SA) is the primary cause of human errors when operating forklifts, so determining the SA level of the forklift operator is crucial to the safety of forklift operations. An EEG recognition approach of forklift operator SA in actual settings was presented in order to address the issues with invasiveness, subjectivity, and intermittency of existing measuring methods. In this paper, we conducted a field experiment that mimicked a typical forklift operation scenario to verify the differences in EEG states of forklift operators with different SA levels and investigate the correlation of multi-band combination features of each brain region of forklift operators with SA. Based on the sensitive EEG combination indexes, Support Vector Mechanism was used to construct a forklift operator SA recognition model. The results revealed that there were differences between forklift operators with high and low SA in the θ, α, and β frequency bands in zones F, C, P, and O; combined EEG indicators θ/β, (α + θ)/(α + β), and θ/(α + β) in zones F, P, and C were significantly correlated with SA; the recognition accuracy of the model reached 88.64% in the case of combined EEG indicators of zones C & F & P as input. It could provide a reference for SA measurement, contributing to the improvement of SA. [ABSTRACT FROM AUTHOR]

This study proposes an energy stability index suitable for a counterbalance forklift, aiming to solve the problem that the traditional vehicle stability index load transfer rate is difficult to accurately judge the stability state of such a forklift. The analysis of the structure of the counterbalance forklift and contact relationship between the body and rear axle are used as bases to establish a two-stage dynamic model and derive real-time instability energy of a forklift truck in the rollover process under different conditions. Additionally, this research proposes an anti-rollover control strategy of the counterbalance forklift based on roll energy classification. The corresponding calculation formula of the forklift energy stability index is selected according to different stability conditions to perform roll energy classification. An anti-rollover oil cylinder and active rear wheel steering are used as an anti-rollover control actuator, and an anti-rollover control is implemented based on model predictive control. Last, a simulation based on European standard operating conditions and real vehicle test verification is conducted. Results show that the anti-rollover control strategy based on roll energy classification can effectively reduce the risk of forklift rollover and improve the stability and active safety of a counterbalance forklift. [ABSTRACT FROM AUTHOR]

To improve the anti-rollover capacity of a counterbalanced forklift, a two-stage rollover dynamic model is established on the basis of the forklift structure. Stable zones are divided according to the two-stage lateral load transfer rate: stable region, relatively stable region, dangerous zone and abnormal dangerous zone. An anti-rollover layered control strategy based on stable zone partition is proposed, and different anti-rollover control actuators are selected: dynamic balance weight, anti-rollover cylinder and steering cylinder. Anti-rollover controllers consist of the upper stable region identification controller, the middle-level controller based on model predictive control (MPC) and the lower layer executive controller. The upper stable region identification controller performs stable zone recognition based on the two-stage lateral load transfer rate. The middle-level MPC controller calculates the required control torque with the body's lateral angle and yaw rate as the control objectives. The lower layer executive controller controls the balance weight, anti-rollover cylinder and the steering cylinder according to the improved chain incremental allocation method to meet the target control torque. Simulation and real vehicle tests based on MATLAB/Simulink show that the anti-rollover control based on stable zone partition can greatly reduce the risk of forklift rollover and improve the forklift safety. [ABSTRACT FROM AUTHOR]

Based on the analysis of the structural characteristics and the rollover mechanism of the counterbalanced forklifts, an anti-rollover control strategy for counterbalanced forklifts was proposed based on extension decision, and the anti-rollover extension hierarchical controller including upper layer extension control and lower layer execution control was designed. The upper layer extension controller divided the forklift anti-rollover control domains into a classic domain, a extension domain, and a non-domain, and determined the weight coefficients of the lower layer execution controller. The lower layer execution controller received the weight coefficients determined by the upper layer extension controller, performed control weight distribution on the yaw rate controller and the lateral acceleration controller, and executed the commands to realize the anti-rollover extension control of the counterbalance forklifts. The European standard condition simulation and real vehicle test results show that the anti-rollover control strategy of the counterbalance forklifts based on the extension decision may effectively reduces the roll ranges of the forklifts under high-speed emergency steering conditions, prevents the forklift from rolling over and improves the stability and active safety of the counterbalance forklift trucks. [ABSTRACT FROM AUTHOR]

For the problem of actuator-integrated fault estimation (FE) and fault tolerant control (FTC) for the electric power steering (EPS) system of a forklift, firstly, a dynamic model of a forklift EPS system with actuator faults was established; then, an integrated FE and FTC design was proposed. The nonlinear unknown input observer (NUIO) was proposed to estimate the system states and actuator faults, and an adaptive sliding mode FTC system was constructed based on it. The gain of the observer and controller is obtained by H ∞ optimization and one-step linear matrix inequality (LMI) formula operation in order to realize the overall optimal design of an FTC system. Finally, the experimental results show that when actuator failure occurs, the proposed integrated FE and FTC were more accurate than the decentralized design to estimate the system states and the actuator faults. The proposed fault-tolerant controller can more effectively restore the power assist performance of the steering power motor in case of failure and effectively ensure the safety and reliability of the forklift EPS system. [ABSTRACT FROM AUTHOR]

Safety and prevention in workplaces are important issues, especially regards to risks with serious consequences for health and infrastructures, such as dust explosions, which have caused several industrial accidents during the last centuries and, actually, represent a critical issue in the industrial framework. The current European legislation, referred to as ATEX directive, identifies ATEX zones as parts of the plant where explosive atmospheres can be generated. In this work, a modified version of the classic Recursive Operability Analysis method, specifically tailored to define with an automatic procedure the ATEX zones related to flammable dust clouds, is proposed. The method is fast and effective, allowing for an automatic generation of fault trees from which the probability of occurrence defining the specific ATEX zone type can be estimated. This technique was successfully implemented in a chemical plant dedicated to the mixing of inert powders with a stearate powder, a hazardous dust classified as strongly explosible. The extent of all the ATEX zones identified within the plant was simulated with the ALOHA software, treating the dispersed dust cloud of stearate as a dense gas cloud. From the results, it was possible to identify not only type and extension of all the ATEX zones but also either the most critical parts of the plant or the most dangerous activities (e.g. human errors in the use of the forklift was found to account for about 97.7% to explosion probability in this type of plant). [ABSTRACT FROM AUTHOR]

The anti-rollover control actuator of a counterbalance forklift is determined by analysing its structural characteristics and roll-over mechanism. An anti-rollover control strategy for counterbalance forklifts based on extension decision is proposed, and the anti-rollover extension hierarchical controller, including the upper-layer extension and lower-layer execution controls, is designed. The upper-layer extension controller divides the forklift anti-rollover control domain into three types, namely, classical domain, extension domain and non-domain, and determines the weight coefficient of the lower-layer execution controller. The lower-layer execution controller receives the weight coefficient determined by the upper-layer extension controller, controls the weight distribution on the yaw rate and lateral acceleration controllers and executes the command to obtain the anti-rollover extension control of the counterbalance forklift. The European standard condition simulation and real vehicle test results show that the anti-rollover control strategy of the counterbalance forklift based on the extension decision can effectively reduce the forklift roll range under high-speed emergency steering conditions, prevent the forklift from rolling over and improve the stability and active safety of the counterbalance forklift. [ABSTRACT FROM AUTHOR]

An anti-roll hydraulic cylinder is designed as an executive mechanism of the lateral stability control to provide lateral support force on the basis of an analysis of the structure of the forklift and the mechanism of lateral instability. A lateral stability layered control method based on Takagi–Sugeno (T–S) fuzzy neural network is proposed, divides the forklift lateral stability control into the upper identification layer, the middle control layer and the lower executive layer. Simulation and real vehicle test results indicate that the forklift lateral stability control method based on the T–S fuzzy neural network can effectively identify the forklift driving state, reduce the forklift rollover possibility and improve forklift safety under limited working conditions. [ABSTRACT FROM AUTHOR]

The article discusses that the Vehicle are important in many U.S. industries from 2009 to 2018, powered industrial trucks, including forklifts, were shipped from manufacturers to customers in the U.S. (ITA, 2019). It mentions that teh Forklifts are used to move supplies and products throughout facilities and onto tractor-trailer vehicles for delivery to customers nationwide.

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the invention of the tyre, no one could have foreseen that over time it would perform such an important function, and without it industry, and everyday life would look completely different. Over time, the use of such an important innovation has created new challenges to be faced. Over the entire lifespan of the tyre, it gradually wears out or is suddenly damaged. An important issue is the ability to predict the remaining lifetime or eliminate any damage that may pose a threat in its further use. The aim of the article is to determine the technical condition of tires used in the selected company, by determining their age, damage, possibility of further use and those which should be withdrawn from service. The first part of the article presents the characteristics of forklift tyres, showing their construction, advantages and disadvantages, and the most common damage. Then the internal transport in which the forklift is used is characterized. In the next, main part of the article, the tyres of forklifts were examined, and the results and analysis of the measurements carried out were presented. The paper provides conclusion that arose during the performance of tests and solutions for users of the tested tyres. [ABSTRACT FROM AUTHOR]

Copyright of Travail Humain is the property of Presses Universitaires de France and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the case of workers performing a series of activities involving the use of equipment that transmit vibrations to the whole body, there is a risk of getting sick. In this paper, we will calculate Vibration magnitude, Partial VDV, Partial exposure, Time to reach EAV (VDV and A(8) option), Time to reach ELV (A(8) option only), Total VDV, Total Exposure A(8) for a worker who uses for the same operation, in 2 different days: i) forklift and lorry (from certain manufacturers), ii) same equipment (from other manufacturers). The methods of calculating daily exposure are: a) Calculation of daily exposure using partial vibration exposures and the duration of each source, b) Calculation of daily exposure using Vibration Dose Value (VDV), c) Daily exposure graph, d) Exposure points system, e) Nomogram of daily exposure, f) Methods that use the Internet. After performing all the calculations, it was found that the fastest and most accurate method is the one that uses the Internet: "Whole-body vibration exposure calculator", because it instantly gives all values of interest. [ABSTRACT FROM AUTHOR]

This paper presents the modelling and simulation of an anti-tip-over control designed for a counterbalance forklift, a highly unstable vehicle in relation with roll and pith angles. The studied forklift is an automated guided vehicle and it does not depend on the human factor, being possible to enhance safety by improving stability. Therefore, the main purpose of this work is to design a control system that improves forklifts’ stability and, at the same time, reduces the transportation times with the subsequent operating cost savings. Firstly, an analytical study is developed, focused on the pitch movement, in order to analyze the stability conditions of the vehicle. Based on this analysis, an anti-tip-over control is designed. This control is based on Model Predictive Control, a robust control technique that is being successfully used in the design of autonomous vehicles. Therefore, the main contribution of this paper is to show the feasibility of the MPC control in this type of vehicles. Several simulations have been done in order to analyze the feasibility of concluding that with the proposed control, it is possible to guaranty the forklift stability without the risk of tip-over, obtaining also better operational results with faster maneuvers than when no control is used. [ABSTRACT FROM AUTHOR]

Manipulation processes represent an important part of the material management in a company. These processes run inside a company and represent an integrated chain of material flow. The current situation regarding the material manipulation is evaluated using the manipulation indicators which may serve as the basis for manipulation system rationalisation designs. The present case study is focused on the determination of an appropriate number of forklift trucks in a given operation and consists of three sections. The introductory section deals with the evaluation of forklift activities while applying the selected analysis and the selected indicators. Analysis results subsequently served as a basis for the calculation. The calculated number of trucks must be properly verified; the verification should be focused on whether the given number of forklifts is actually sufficient for the performance of the current activities. The activities were verified while applying the simulation. A simulation model was created using the Technomatix Plan Simulation software. [ABSTRACT FROM AUTHOR]

90 accidents involving forklift trucks occur each year in Poland, resulting in nearly 100 injured persons including 10–15 fatalities. The most frequent and most dangerous accidents include those caused by the loss of stability of a forklift truck with the operator inside, resulting in its tip-over. More than a half of this type of incidents have a fatal outcome. The paper describes results of tests aimed at verifying the effectiveness of passive safety systems used to protect the operator against the effects of the truck tip-over. The tests were performed with the use of numerical simulation. The authors selected 12 configurations taking into account the forklift’s velocity, position of the steering wheel and seat and the operator’s reaction, in terms of which selected passive safety systems were tested. In order to conduct the effectiveness tests of these systems, a simulation model was developed, consisting of numerical models of: a forklift truck, human body, ground and tested passive safety systems. This was followed by a series of simulations of the forklift tip-over with the operator inside, with the use of different passive safety systems. More than 170 simulations of possible cases were performed in total. Results, in the form of recorded resultant acceleration of the head, were used to estimate the severity of injuries for each case considered. This was used as a basis to determine the effectiveness of the passive safety systems. [ABSTRACT FROM AUTHOR]

The article reviews a selection of occupational safety and health products including Orange Forklift Traffic Banner from BannerStakes, Flame Resistant Featherlight work shirt for women from Ariat and Zenith X safety helmet from Kask.

The article discusses the effectiveness of magnetic field proximity-sensing technology deployed in an active indoor manufacturing environment. It examines the effectiveness of a select proximity-sensing system using a test bed and experimental trials. It demonstrates the ability of proximity-sensing system to alert pedestrian workers and forklift operators when a hazardous proximity situation exists.