Differential Steering Control Research Articles

Coordinated Control of Differential Drive-Assist Steering and Direct Yaw Moment Control for Distributed-Drive Electric Vehicles

Direct yaw moment control (DYC) and differential drive-assist steering (DDAS) for distributed-drive vehicles are both realized by allocating the in-wheel motor torque. To address the interference caused by overlapping control objectives, this paper proposes a multilayer control strategy that integrates DYC and DDAS, consisting of an upper controller, a coordinated decision layer, and a torque distribution layer. The upper controller, designed based on the vehicle’s dynamic characteristics, incorporates an adaptive fuzzy control DYC system and a dual PID control DDAS system. The coordinated decision layer is developed utilizing a phase-plane dynamic weighting method, delineating region boundaries by applying the double-line and limit cycle methods. The torque distribution strategy is formulated considering motor peak torque and road adhesion conditions. Multi-condition joint simulation experiments indicate that the proposed multilayer control strategy, integrating the advantages of DYC and DDAS, reduces peak steering wheel torque by approximately 10%, peak yaw rate by around 25%, peak sideslip angle by roughly 29%, and peak sideslip angle rate by about 19%, significantly improving driving stability and maneuvering flexibility.

Differential Steering Control Based on CNF and ADRC Techniques for Distributed-Drive Articulated Heavy Vehicles

Differential Steering Control Based on CNF and ADRC Techniques for Distributed-Drive Articulated Heavy Vehicles

Research on Electronic Differential Steering Control Strategy for Aircraft Electric Tractors

Compared with the traditional fuel aircraft tractor, the electric tractor using the four-wheel hub motor independent drive mode has the advantages of environmental protection, low costs, flexibility, high controllability, and convenience for later maintenance. The paper uses a four-wheel hub motor tractor and a linear vehicle model to propose a hierarchical steering control strategy. The upper layer control adopts the improved integrated sliding mode control algorithm with the yaw angular speed as the control goal to obtain the additional yaw torque. The additional yaw torque obtained is reasonably distributed to each wheel by the use of the rule distribution algorithm of the lower layer control, to obtain the optimal driving torque of each wheel. Finally, the steering stability of the electric aircraft tractor at different speeds is verified based on Simulink. The results show that the control strategy can better control the speed and stability of steering control of electric vehicles.

Longitudinal and Lateral Stability Control Strategies for ACC Systems of Differential Steering Electric Vehicles

To ensure lateral stability during the cruising of a differential steering vehicle (DSV), this paper presents a curving adaptive cruise control (ACC) system coordinated with a differential steering control (DSC) system, which considers both longitudinal cruising capability and lateral stability on curved roads. Firstly, a DSV dynamics model is developed and a control strategy architecture for a curving ACC system is designed. Then, the car-following control strategy for the curving ACC system is designed based on the fuzzy model predictive control (FMPC) algorithm. The strategy aims to improve the economy and balances car following, safety, comfort and economy. Moreover, fuzzy logic rules are designed to update the weight coefficients of the performance indicators in real time. Finally, the lateral stability controller is designed based on the preview algorithm and the sliding mode control (SMC) algorithm. The simulation results show that the lateral stability of the DSV during the curving cruise is realized via the control of the differential drive torque of the two front wheels. The proposed FMPC controller and SMC controller based on the preview control algorithm satisfy the performance in terms of vehicle following and lateral stable driving in the process of cruising.

Simulation and Validation of a Steering Control Strategy for Tracked Robots

Tracked inspection robots have demonstrated their versatility in a wide range of applications. However, challenges arising from issues such as skidding and slipping have posed obstacles to achieving precise and efficient trajectory control. This paper introduces a method to determine the steering parameters of robot based on the surrounding obstacles and road information. The primary objective is to enhance the steering efficiency of tracked robots. The corresponding relationship between the track speed, driving force and track steering radius of the tracked robot is obtained. Considering the influence of track skid and slip, relationship models about the steering radius and traveling speed of the robot are established. The minimum and maximum steering radii in the obstacle avoidance process are analyzed, and a mathematical model of the relationship between the steering angle of the robot and the distance between the side obstacles is established. The trajectory deviation model of the tracked robot is established, and a principle analysis of the LiDAR ranging is completed. This lays the foundation for a steering measurement and control system for tracked robots. ADAMS(2020) software is used to establish the multi-body dynamics model of the tracked robot, and three different obstacle-avoiding steering control strategies are designed for the robot in a simulated environment with space obstacles. The simulation experiment demonstrates that the robot achieves more efficient obstacle avoidance steering through the use of differential steering, leading to a decrease in both track skid and slip rates. Through the simulation experiment, it can be seen that the robot uses differential steering to complete the obstacle avoidance steering movement more efficiently, and the track skid and slip rates are smaller. The simulation results are used to complete the steering control experiment of the tracked robot on different road surfaces. The results show that by adjusting the track driving parameters, the robot can effectively complete the obstacle-avoiding steering movement by using the differential steering control strategy, which verifies the accuracy of the steering control strategy.

Coordinated Control Method for Lateral Stability and Differential Power-Assisted Steering of In-Wheel Motor Drive Electric Vehicles

In order to improve the lateral stability and handling performance of in-wheel motor drive electric vehicles, a coordinated control method considering lateral stability and differential power-assisted steering performance is proposed. A vehicle dynamics model with two degrees of freedom is established, in which the influence of system disturbance is considered. At the same time, the effect of differential torque on vehicle power-assisted steering control was analyzed, and a differential power-assisted steering control method of vehicle was designed based on referenced steering wheel torque. In response to the coupling relationship and dynamic game problem between the lateral stability control system and the differential power-assisted steering control system, a coordinated control system with a vehicle lateral stability module and a differential power-assisted steering module was designed based on the Nash equilibrium game theory, achieving comprehensive optimization of multi-objective performance. Corresponding simulation tests were conducted in the co-simulation vehicle model, and the results show that the proposed coordinated control method can achieve the differential power-assisted steering control function of vehicle while ensuring lateral stability.

Coordination Control of Maneuverability and Stability for Four-Wheel-Independent-Drive EV Considering Tire Sideslip

Four-wheel-independent-drive electric vehicle (EV) can generate the active yaw moment by the differential torque to change the steering characteristics such as oversteer or understeer. However, the utilization of the same actuators implies that the stability and flexibility will interfere with each other. This article proposes a coordination control strategy to simultaneously improve the low-speed flexibility and high-speed stability of the vehicle. First, the geometry of the vehicle steering and the steady-state steering characteristics under active yaw moments are analyzed. Subsequently, a gain scheduling controller is designed to adjust the magnification of the yaw rate based on the driver’s intention. Next, a feedforward and an enhanced sliding mode controller are applied to quickly track the target motion. Due to the overlapping nature of the actuators in the differential drive-assisted steering (DDAS) and vehicle stability control (VSC) system, the coordination strategy is developed based on the phase plane theory. Moreover, a torque distribution algorithm derived from the modified extreme value method with lesser calculation is proposed. Finally, simulations and experiments under relevant conditions are conducted to verify the effectiveness and the reliability of the designed control strategy. The results suggest that the proposed strategy can significantly improve maneuverability and ensure vehicle stability.

A Control Method for the Differential Steering of Tracked Vehicles Driven Independently by a Dual Hydraulic Motor

It is well known that tracked vehicles can adapt well to all kinds of terrain. However, the safety of tracked vehicles should be considered during steering on sloped terrain. This paper focuses on the differential steering control of tracked vehicles independently driven by a hydraulic motor. Firstly, the dynamic model of hydrostatic drive system was built and the kinematics and dynamics of differential steering driving were analyzed theoretically. Secondly, in order to prevent rollover of the tracked vehicle, the method of vehicle speed constraint was proposed. The constraint conditions of vehicle speed and steering angular velocity were analyzed under different slope conditions. Thirdly, based on the analysis results, differential steering control rules for tracked vehicles were formulated. To verify the effectiveness of the control rules, the models of vehicle driving dynamics and Fuzzy PID control simulation were established in MATLAB/Simulink. Longitudinal steering simulation was carried out on a slope (0°, 30°), and an analysis of the simulation of lateral steering along the contour line was carried out. The simulation results showed that this steering control strategy was able to automatically adjust the target vehicle speed to avoid rollover while the driver was inputting steering signals.

Experimental Study of Electric Vehicle Yaw Rate Tracking Control Based on Differential Steering

This paper investigates the experimental study of differential steering control of a four-wheel independently driven (FWID) electric vehicle (EV) based on the steer-by-wire (SBW) system. As each wheel of FWID vehicle can be independently driven, differential steering is realized by applying different driven torques to the front-two wheels. Firstly, the principle of the differential steering is analyzed based on the SBW system. When the differential steering is activated, the driver’s steering request is sent to the vehicle’s ECU. Then, the ECU gives different control signals to the front-left and front-right wheels, generating an external steering force on the steering components. The external steering force pushes the steering components to turn corresponding to the driver’s request. Secondly, to test the feasibility of differential steering, a FWID EV is assembled and the vehicle is equipped with four independently driven in-wheel motors. The corresponding control system is designed. Finally, the field test of the vehicle based on the proposed differential steering control strategy is performed. In the experiment, the fixed yaw rate tracking and varied yaw rate tracking maneuvers are employed. In the fixed yaw rate tracking, the vehicle can track the desired yaw rate well with differential steering. In addition, the vehicle can track the varied yaw rate with proposed differential steering. The test results confirm the feasibility and effectiveness of the differential steering. By using the differential steering, a backup steering is established without additional components; thus, the costs can be reduced and the reliability of the vehicle steering system can be enhanced, significantly.

Four-Wheel Differential Steering Control of IWM Driven EVs

This paper aims to realize the four-wheel differential steering function of an in-wheel motor (IWM) driven electric vehicle (EV) with a steer-by-wire (SBW) system. The dynamic models of four-wheel differential steering vehicle (4WDSV) and four-wheel steering vehicle (4WSV) are established, and a front-wheel steering vehicle (2WSV) with the neutral steering characteristics and a drop filter of the sideslip angle is employed as the reference model to provide the ideal yaw rate and sideslip angle. According to the reference model, the decoupling and fractional PI λ D μ controllers are designed for the 4WSV to obtain the standard inputs, i.e., the front and rear wheel steering angles, which is finally drawn as the MAP. Furthermore, the sliding mode controller (SMC) and torque distributor are designed to control the 4WDSV to have the same yaw rate as the 4WSV, whose inputs are consulted from the MAP drawn in advance according to the vehicle speed. The simulation results of several vehicle models with/without the controller of two working conditions (reverse and in phase steering) are presented, which indicates that the proposed decoupling and fractional PI λ D μ controller for the 4WSV is effective to obtain its standard inputs, and the proposed SMC and torque distributor for the 4WDSV ensure that it has the same yaw rate as the 4WSV, as well as the good robustness.

Research On Differential Steering Control Strategy Of Distributed Electric Drive Vehicle

Research On Differential Steering Control Strategy Of Distributed Electric Drive Vehicle

Differential steering-based electric vehicle lateral dynamics control with rollover consideration

This article investigates the differential steering-based schema to control the lateral and rollover motions of the in-wheel motor-driven electric vehicles. Generated from the different torque of the front two wheels, the differential steering control schema will be activated to function the driver’s request when the regular steering system is in failure, thus avoiding dangerous consequences for in-wheel motor electric vehicles. On the contrary, when the vehicle is approaching rollover, the torque difference between the front two wheels will be decreased rapidly, resulting in failure of differential steering. Then, the vehicle rollover characteristic is also considered in the control system to enhance the efficiency of the differential steering. In addition, to handle the low cost measurement problem of the reference of front wheel steering angle and the lateral velocity, an [Formula: see text] observer-based control schema is presented to regulate the vehicle stability and handling performance, simultaneously. Finally, the simulation is performed based on the CarSim–Simulink platform, and the results validate the effectiveness of the proposed control schema.

Robust Differential Steering Control System for an Independent Four Wheel Drive Electric Vehicle

This research investigates a robust differential steering control system (DSCS) for an independent four wheel drive electric vehicle (EV). The DSCS will maneuver the independently actuated (IA) four wheel drive EV without the help of any conventional steering mechanism (CSM) via the input torque of the four wheels. The differential angular rotation speed between left and right wheels is used to generate the CSM effects. The DSCS is designed using the linear model of the vehicle with linear tire dynamics and is tested in simulations using a nonlinear vehicle model with nonlinear tire dynamics. The proposed DSCS is a combination of forward speed and yaw rate controllers, designed using the robust H∞ control methodology. The effectiveness of the proposed robust controller is analyzed by comparing the performance of the all-wheel drive (AWD), the rear wheel drive (RWD), and the front wheel drive (FWD) vehicles during simulations. The simulations results indicates that the proposed system can successfully maneuver the vehicle under different driving conditions by tracking the desired parameters without the use of any CSM.

Coordinated control for path following of two‐wheel independently actuated autonomous ground vehicle

This study investigates the path following control problem about distributed-drive self-driving vehicle through coordinated control of the autonomous front-wheel steering and the differential steering control, to improve the tracking performance. On the basis of the model predictive control algorithm and vehicle dynamic model, the preview time adaptive control of path following is proposed to realise path following with changing preview time in straight and turning conditions. Considering the characteristics of the distributed-drive self-driving vehicle, the differential torque control is utilised based on the reference heading angle to realise trajectory tracking under the condition of constant torque demands. To integrate the advantages of the two methods, coordinated control of trajectory tracking based on the autonomous steering and differential steering is performed by setting the weight coefficients method. MATLAB co-simulation with Carsim and road testing validation are executed, and both demonstrate that the coordinated control strategy can not only effectively improve the response speed and flexibility of steering, but also improve the reliability and accuracy of trajectory tracking.

Differential Steering Control of Four-Wheel Independent-Drive Electric Vehicles

This paper investigates the skid steering of four-wheel independent-drive (4WID) electric vehicles (EV) and a differential steering of a 4WID EV with a steer-by-wire (SBW) system in case of steering failure. The dynamic models of skid steering vehicle (SSV) and differential steering vehicle (DSV) are established and the traditional front-wheel steering vehicle with neutral steering characteristics is selected as the reference model. On this basis, sideslip angle observer and two different sliding mode variable structure controllers for SSV and DSV are designed respectively. Co-simulation results of CarSim and Simulink show that the designed controller for DSV not only controls the yaw rate and sideslip angle of DSV to track those of the reference model exactly, but also ensures the robustness of the controlled system compared with the designed controller for SSV. And the differential driving torque needed to realize the differential steering is much smaller than that for skid steering, which indicates the possibility of the differential steering in case of steering failure.

The study on Differential Steering Control of In-wheel Motor Vehicle Based on Double Closed Loop System

This paper describes a novel differential steering control system for an in-wheel motor electric vehicle with four axles. Basically, the vehicle dynamic model and the differential steering model are established based on the platform of MATLAB/Simulink respectively. A two-degree-of-freedom vehicle model is established to get the referential yaw rate. Next, a double closed loop control system based on the sliding mode structure control is proposed to improve the handing stability. The yaw rate is controlled through a differential torque controller. Meanwhile, a torque compensation controller for non-steering wheel motors is designed to solve the problem of steering power loss. Furthermore, the simulation for validation is performed. The results show that the control system can regulate the vehicle states effectively to enhance the stability. The simulation also indicates that the control strategy can provide a good performance even in complex driving conditions.

Vehicle dynamics control by using a three-dimensional stabilizer pendulum system

ABSTRACTActive safety systems of a vehicle normally work well on tyre–road interactions, however, these systems deteriorate in performance on low-friction road conditions. To combat this effect, an innovative idea for the yaw moment and roll dynamic control is presented in this paper. This idea was inspired by the chase and run dynamics animals like cheetahs in the nature; cheetahs have the ability to swerve while running at very high speeds. A cheetah controls its dynamics by rotating its long tail. A three-dimensional stabilizer pendulum system (3D-SPS) resembles the rotational motion of the tail of a cheetah to improve the stability and safety of a vehicle. The idea has been developed in a stand-alone 3D stabilizer pendulum system as well as in an integrated control system, which consists of an ordinary differential braking direct yaw control (DYC) and active steering control that is assisted by the 3D-SPS. The performance of the proposed 3D-SPS has been evaluated over a wide range of handling manoeuvres by using a comprehensive numerical simulation. The results show the advantage of 3D-SPS over conventional control approaches, which are ineffective on low-friction road conditions and high lateral acceleration manoeuvres. It should however be noted that the best vehicle dynamics performance is obtained when an integrated 3D-SPS and DYC and AFS is utilised.

Inter-row Robot Navigation using 1D Ranging Sensors

Abstract: In this paper a fuzzy logic navigation controller for an inter-row agricultural robot is developed and evaluated in laboratory settings. The controller receives input from one-dimensional (1D) ranging sensors on the robotic platform, and operated on ten fuzzy rules for basic row-following behavior. The control system was implemented on basic hardware for proof of concept and operated on a commonly available microcontroller development platform and open source software libraries. The robot platform used for experimentation was a small tracked vehicle with differential steering control. Fuzzy inferencing and defuzzification, step response and cross track error were obtained from the test conducted to characterize the transient and steady state response of the controller. Controller settling times were within 4 seconds. Steady state centering errors for smooth barrier navigation were found to be within 3.5% of center for 61 cm wide solid barrier tests, and within 38% for simulated 61 cm corn row tests.

The Control Strategy and Experimental Analysis of Electronic Differential Steering for Four Independent Drive Hub Motor Electric Vehicle

Wheel hub motor used in drive system of pure electric vehicle has become hot research and future development. Based on a four-wheel independent drive(4WID) electric vehicles with wheel hub motors, the paper has made the research on electronic differential steering control strategy by using Ackermann steering model conditions, and the experimental results have also been analyzed for the actual steering control effects under differential control strategy.

Differential Speed Steering Control for Four-Wheel Independent Driving Electric Vehicle

The increasing prospect of electric drive vehicles has led many different control schemes to apply on the driving system. Differential speed steering which do not use traditional steering mechanism is studied on a four-wheel-driving vehicle. By comparison with the traditional Ackerman-steered vehicle, differential-steered method shown its advantage on the simple structure. However, since the steering performance is coupling with the velocities of all wheels, the strategy of differential speed control is a technological challenge. With the analysis of kinematic model of the vehicle, the relation between the turning behavior and the wheel parameters are investigated. A steering speed control is proposed to get a steady turning performance. The control strategy is implemented in a simulation to verify its rationality.