Independent Steering System Research Articles

Analysis of consumer preferences for new electric vehicle technologies: Can future vehicle steering system steer consumer's purchase intention?

As the mainstream of vehicle industry is moving from internal combustion engine vehicles to electric vehicles (EVs), a multi-perspective analysis of consumer preference for the new EV technology is required. Therefore, this study proposes a new framework for consumer preference analysis—a two-stage choice experiment—and conducts an empirical analysis of the four-wheel independent steering system (4-WISS). In the first stage, we analyzed consumer preference for the availability of 4-WISS in EVs. In the second stage, we investigated consumer preference for the specific technology of 4-WISS in EVs. Stated preference data were collected through a choice experiment survey, and a mixed logit model was used to quantitatively analyze consumer preference and willingness-to-pay. Results show that consumers are willing to pay KRW 19,045,098.6 (USD 13,513.9) to use 4-WISS in high-end EVs. Furthermore, consumers who are female, older, and have more knowledge of autonomous vehicles prefer 4-WISS more. We found that consumers prefer the parallel movement among 4-WISS modes, the touch display for selecting 4-WISS, the steering wheel for operating 4-WISS mode, and dashboard for displaying information. We finally discuss the new business model in the vehicle industry and suggest automakers to establish an effective strategy for the initial market for EVs with 4-WISS.

Active Fault-Tolerant Control of a Four-Wheel Independent Steering System Based on the Multi-Agent Approach

In this paper, we present an active fault-tolerant, vehicle motion control, based on the multi-agent approach for a four-wheel independent steering system. This improves handling stability and active safety of the vehicle in the case of actuator faults. Firstly, an eight-degree-of-freedom four-input vehicle model is established by using the vector transformation method, which takes the four-wheel angle as the input and the yaw rate and the sideslip angle, obtained by the lateral force of a single wheel, as the outputs. Then, we established the topological structure of the four-wheel independent steering subsystems based on graph theory. Aiming at the known fault conditions, an adaptive sliding mode active fault-tolerant control based on the multi-agent four-wheel independent steering system is proposed, in which the unmodeled part of the system is estimated using adaptive methods. For unknown fault conditions, an active fault-tolerant control of the four-wheel independent steering system based on state observer is proposed. An extended state observer with sliding mode surface function as a state variable is designed to estimate actuator faults. Finally, it was demonstrated that the designed state observer and distributed active fault-tolerant control method reduced the impact of actuator failures on vehicle steering and improved the stability of the steering process based on the Lyapunov theory. The hardware in the loop experimental results validate the effectiveness of the proposed novel method.

A Novel Real-Time Robust Controller of a Four-Wheel Independent Steering System for EV Using Neural Networks and Fuzzy Logic

In this study a four-wheel independent steering (4WIS) system for an electric vehicle (EV) steered by stepper motors is presented as a revolutionary real-time control technique employing neural networks in combination with fuzzy logic, where the use of the neural network greatly simplifies the computational process of fuzzy logic. The control of the four wheels is based on a variation of a Hopfield Neural Network (VHNN) method, in which the input is the error of each steering motor and the output is processed by a hyperbolic tangent function (HTF) feeding the fuzzy logic controller (FLC), which ultimately drives the stepper motor. The whole system consists of the four aforementioned blocks which work in sync and are inseparable from each other with the common goal of driving all the steering stepper motors at the same time. The novelty of this system is that each wheel monitors the condition of the others, so even in the case of the failure of one wheel, the vehicle does not veer off course. The results of the simulation show that the suggested control system is very resilient and workable at all angles and speeds.

Optimal Design of the Six-Wheel Steering System with Multiple Steering Modes

Vehicles will face different working conditions during the use, and different working conditions have different requirements for vehicle functions, which results in many subdivided models. An off-road vehicle is a subdivision model produced to adapt to complex road conditions. In order to adapt to complex road conditions, vehicles should have a good passing ability, small size, and good flexibility. The six-wheeled vehicle has both good passing ability and small volume, which is the best choice for off-road vehicles. The design of the steering system becomes the key step to improve the flexibility of the six-wheeled vehicle. This paper mainly designs an independent steering system for a six-wheel electric vehicle with higher flexibility. The system is designed for six-wheel electric vehicles driven by six in-wheel motors. It mainly includes mechanical steering system and electronic control steering system. Both mechanical steering systems and electronic control steering system have multiple steering modes. Firstly, this paper introduces the various steering modes of the mechanical steering system and the electronic control steering system. Secondly, a CAD model is established by using the software Solidworks, and the system structure is introduced in detail combined with the CAD model. Finally, a kinematics model is established and calculated. The calculation results showed that the steering system can significantly improve the flexibility of the vehicle, so that the vehicle can complete the steering stably and quickly on complex road sections.

Four wheel independent steering system control of distributed electric vehicle based on heterogeneous multi-agent

Four wheel independent steering system control of distributed electric vehicle based on heterogeneous multi-agent

Four wheel independent steering system control of distributed electric vehicle based on heterogeneous multi-agent

Four wheel independent steering system control of distributed electric vehicle based on heterogeneous multi-agent

Research on four‐wheel independent steering intelligent control strategy based on minimum load

AbstractAround the new four‐wheel independent steering system, the adjustment principle of Akman angle is studied in this article. In order to improve steering stability and reduce tire wear, a new algorithm for optimal Ackerman angle allocation at full speed is proposed. Furthermore, combined with the minimum load rule, the four‐wheel rotation angle and driving force are optimized. In this process, Carsim vehicle model and MATLAB/Simulink force and angle allocation algorithm model are established. The final system simulation and performance evaluation demonstrate the effectiveness of the proposed force and angle distribution algorithm for vehicle stability and tire wear optimization.

Hierarchical Synchronization Control Strategy of Active Rear Axle Independent Steering System

The synchronization error of the left and right steering-wheel-angles and the disturbances rejection of the synchronization controller are of great significance for the active rear axle independent steering (ARIS) system under complex driving conditions and uncertain disturbances. In order to reduce synchronization error, a novel hierarchical synchronization control strategy based on virtual synchronization control and linear active disturbance rejection control (LADRC) is proposed. The upper controller adopts the virtual synchronization controller based on the dynamic model of the virtual rear axle steering mechanism to reduce the synchronization error between the rear wheel steering angles of the ARIS system; the lower controller is designed based on an LADRC algorithm to realize an accurate tracking control of the steering angle for each wheels. Experiments based on a prototype vehicle are conducted to prove that the proposed hierarchical synchronization control strategy for the ARIS system can improve the control accuracy significantly and has the properties of better disturbances rejection and stronger robustness.

Turning control of a mobile robot for greenhouse spraying based on dynamic sliding mode control

The road of a greenhouse is both damp and narrow, and there are both ground obstacles and space obstacles in a greenhouse, which easily cause the instability problem for a four-wheel independent driving greenhouse spraying mobile robot turning in the greenhouse. In order to improve the steering performance of the greenhouse spraying mobile robot, based on the characteristics that each wheel torque of the robot can be separately controlled, the dynamic model of the four-wheel independent steering system is firstly established using D’Alembert’s principle and choosing the sideslip angle and the yaw velocity as the state variables. Then, based on the theory of sliding mode control, a dynamic sliding mode control strategy with exponential approaching rate is proposed by adopting the sideslip angle and the yaw velocity as the joint control variables in order to make the sideslip angles be in the stable range and make the yaw velocity track the desired value well. Finally, the simulation of the steering performance is performed using MATLAB/Simulink. The control response curves of the yaw velocity and the sideslip angle of the robot’s mass center in a step input and in a sinusoidal input are obtained, respectively. It is shown from the simulation results that compared with the feedforward–feedback control method, the proposed dynamic sliding mode control strategy based on the established dynamic model is effective to improve the turning control stability of the mobile robot for greenhouse spraying. The experiment results further verify the feasibility of the proposed turning control strategy.

Development of a tomato harvesting robot used in greenhouse

A tomato harvesting robot was developed in this study, which consisted of a four-wheel independent steering system, a 5-DOF harvesting system, a navigation system, and a binocular stereo vision system. The four-wheel independent steering system was capable of providing a low-speed steering control of the robot based on Ackerman steering geometry. The proportional-integral-derivative (PID) algorithm was used in the laser navigation control system. The Otsu algorithm and the elliptic template method were used for the automatic recognition of ripe tomatoes, and obstacle avoidance strategies were proposed based on the C-space method. The maximum average absolute error between the set angle and the actual angle was about 0.14°, and the maximum standard deviation was about 0.04°. The laser navigation system was able to rapidly and accurately track the path, with the deviation being less than 8 cm. The load bearing capacity of the mechanical arm was about 1.5 kg. The success rate of the binocular vision system in the recognition of ripe tomatoes was 99.3%. When the distance was less than 600 mm, the positioning error was less than 10 mm. The time needed for recognition of ripe tomatoes and pitching was about 15 s per tomato, with a success rate of about 86%. This study provides some insights into the development and application of tomato harvesting robot used in the greenhouse. Keywords: tomato harvesting robot, four-wheel independent steering, automatic navigation, binocular stereo vision system, obstacle avoidance, greenhouse DOI: 10.25165/j.ijabe.20171004.3204 Citation: Wang L L, Zhao B, Fan J W, Hu X A, Wei S, Li Y S, et al. Development of a tomato harvesting robot used in greenhouse. Int J Agric & Biol Eng, 2017; 10(4): 140–149.

Independent wheel steering control design based on variable-geometry suspension

The paper presents the control design of an independent wheel steering system for in-wheel electric vehicles. The steering of the wheels is based on the variable-geometry suspension control, which influences the camber angle and the scrub radius of the wheel. A nonlinear formulation of the variable-geometry suspension is derived, which is validated through a high-fidelity suspension model. Furthermore, the impact of the independent steering in the lateral model of the vehicle is incorporated. In the paper the robust control design of the independent steering system in a hierarchical structure is presented. The trajectory tracking of the vehicle is guaranteed by the robust H∞ control, while the intervention of the variable-geometry suspension is designed based on the Linear Quadratic theorem.

The Design and Characteristic Analysis of the Steering System of Balanced Rocker Wheeled Chassis

According to the particularity of balanced rocker wheeled chassis, a four wheel independent steering system was designed. The chassis of the two degree of freedom model was established, the proportional feedback control of yawing angular velocity and front wheel Angle-yawing angular velocity was simulated, the chassis steering performance under the two classic control methods was analyzed, then the dynamics of mechanical model was established in ADAMS software, the steering performance under different speed was simulated. At last, compared with two simulation results, it was proved that the steering system has good handling stability.

전차륜 독립휠 구동 및 조향 제어 기반 특수목적용 6WD/6WS 차량의 주행제어 알고리즘 연구

This paper discusses the maneuvering control algorithm based on all-wheel independent driving and steering control techniques for special purpose 6WD/WS vehicles. The maneuvering control algorithms considering superior dynamic characteristics of high power in-wheel motors and independent steering system are designed to perform driving, steering, vehicle stability, and fault tolerant control. The maneuvering controller applies sliding and optimal control theories considering optimal torque distribution and friction circle related to the vertical tire force. The fault tolerant control algorithm is applied to obtain the similar maneuverability to that of the non-faulty vehicle. The simulations using the Matlab/Simulink dynamics model and experiments using HIL simulator mounting the real controllers with the designed control algorithms prove the improved performances in terms of vehicle stability and maneuverability.