All-wheel Steering Research Articles

Develop an RS-485 Protocol for Arduino Boards Applied To Networked Real Time Control Systems

The Arduino microprocessor boards such as Mega 2560, UNO R3, Leonardo, Micro, and Nano are simple and low-cost tools for real-time measurement and control applications. These Arduino boards cannot be used in distributed systems because they lack the networking capabilities to transfer data across units. In this study, an RS-485 protocol for Arduino boards that operate in Master-Slave networks was developed. Network operations could be carried out independently on the main thread program, and devices in the network could react quickly to information received. This was made possible by the asynchronous serial communication feature and a high-speed timer provided in Arduino boards. The networks designed in this study were applied to an electric vehicle model with all-wheel drive and all-wheel steering capabilities for supermaneuverability as well as a saltwater intrusion early warning system installed in a river entry. The results showed that highly reliable and stable network operations could be achieved, thus extending the usage of popular Arduino boards for networked real-time applications.

All-Wheel Steering Tracking Control Method for Virtual Rail Trains with Only Interoceptive Sensors

A virtual rail train (VRT) is a multi-articulated vehicle as well as a novel public transportation system due to its low economic cost, environmental friendliness and high transit capacity. Equipped with all-wheel steering (AWS) and a tracking control method, the super long VRT can travel on urban roads easily. This paper proposed a tracking control approach using only interoceptive sensors with high scene adaptivity. The kinematic model was established first under reasonable assumptions when the sensor configuration was completed simultaneously. A hierarchical controller consists of a front axle controller and a rear axle controller. The former applies virtual axles theory to avoid motion interference. The latter generates a first-axle reference path with path segmentation and a data updating method to improve storage and computational efficiency. Then, a fast curvature matching rear axles control method is developed with an actuator time delay considered. Finally, the proposed approach is verified in a hardware in loop (HIL) simulation under various situations with predefined evaluation standards, which shows better tracking performance and applicability.

Open ECU EPS System, preliminary design using a Hardware-in-the-loop approach

The introduction of mechatronic systems in vehicles opens the possibility to a wide range of vehicle functionality. These systems allow active control of vehicle enabling a new level of driving comfort and safety. The development of these complex technological systems, however, requires a long time to integrate mechanical, electrical and software components. Innovative development strategies and devices are hence crucial to accelerate the integration and deployment of these mechatronic systems.In order to fulfil these needs, this paper presents the process to size a development electronic power steering which aims to support vehicle industry during testing and validation of innovative steering-based control strategies, including autonomous driving, steer-by-wire and all-wheel steering applications. Using an hardware-in-the-loop test bench for a wide range of vehicle maneuvers a stock power steering unit has been characterized taking into account both driver and assistance motor torque contributions.

Simulation and Validation of an 8 × 8 Scaled Electric Combat Vehicle

In this research, an 8 × 8 scaled electric combat vehicle (SECV) is built. The scaled vehicle is evaluated in both experimental and simulated methods to analyze its performance. The scaled vehicle is developed to apply the Ackermann condition by implementing the individual steering and individual wheel speed control system at low speed. Individual eight-wheel rotational velocity control and individual eight-wheel steering angle control in real time are developed and installed on the remotely controlled scaled vehicle to meet a perfect Ackermann condition. Three different steering scenarios are developed and applied: a traditional steering scenario (first and second axle steering), fixed third axle steering scenario (first, second, and fourth axle steering), and all-wheel steering scenario. Stationary evaluation, turn radius evaluation, and double lane change evaluation are conducted to verify the application of the Ackermann condition. The differences between the experimental results and the simulated data are within an acceptable range. An important demonstration of this research is the novel validation of physical and simulated data in the application of the Ackermann condition for eight-wheel steering and velocity control for the three steering scenarios.

Multiobjective Synchronous Control of Heavy-Duty Vehicles Based on Longitudinal and Lateral Coupling Dynamics

The steering system, suspension system, and braking system of the vehicle are interrelated, so the ride comfort and handling stability of the vehicle are also closely related. But the vertical and lateral dynamics equations and controls system of the vehicle are always independent of each other, and the multiobjective control is generally achieved through the coordination of control algorithms. In this paper, taking the dynamic load of the tire as a link, the vertical dynamic model and the lateral dynamic model of heavy-duty vehicle are coupled. When the heavy-duty vehicle is turning, the proposed coupling model not only reflects the influence of the front wheel angle on the vertical motion and the vertical tire load, but also reflects the unevenness of the road surface on vehicle lateral motion. In order to improve the handling stability and transient safety of the vehicle, a synchronous control system combining six-wheel steering and front wheel active steering is proposed. It solves the problem that it is difficult to effectively track the desired yaw rate for the three-axle all-wheel steering vehicle with the middle rear wheel angle as the control input. Under the framework of the vehicle vertical/lateral unified coupling dynamics model, the semiactive suspension system controlled by fuzzy PID and the six-wheel active steering system combined with fuzzy control and fuzzy PID control are integrated. It is verified that the synchronous control method effectively optimizes the vertical and lateral motion characteristics of heavy-duty vehicles during steering and, at the same time, improves the ride comfort and steering stability.

단일 모터 및 선형 구동기 기반의 기동성이 향상된 4 륜 선형 조향 구조 설계

In this paper, we propose a new steering structure to improve the structural robustness and maneuverability of the original steering structure designed in our previous study. Most mobile robot platforms are designed with a differential drive or all-wheel steering (AWS) models. Differential-drive robots have a simple structure and are easy to manufacture, but this structure causes considerable slipping when the robots rotate. The AWS model has such a high maneuverability that it can reduce slip, but this structure requires as many steering motors as driving motors. To address these problems, in our previous research, we designed the steering structure to be as highly maneuverable as AWS models using a single steering motor and a solenoid actuator. However, the original structure requires nonlinear control and is too complex to analyze for selecting the proper steering motor. Thus, in this work, we design a steering structure with a simpler mechanical structure that has structural robustness and is easy to analyze, control, and manufacture. In addition, the proposed structure can steer faster than the original one and even move a four-wheel robot horizontally.

Path-following enhancement of an 8×8 combat vehicle using active rear axles steering strategies

Active rear steering has been used in many research work to enhance ground vehicles’ lateral stability. However, there is a shortage in the published research studies that consider the incorporation of active rear steering for autonomous vehicles applications, especially in case of multi-axle combat vehicles. In this paper, various H∞ controllers are developed to actively steer rear axles of a multi-axle combat vehicle using a linearized bicycle model. The proposed controllers are incorporated with a 22 degrees of Freedom nonlinear Trucksim full vehicle model to study and compare the developed controllers’ performance on a hard surface. Moreover, a frequency-domain analysis is conducted to investigate the influence of the active rear steering on the path-following controllers’ robustness in terms of stability and performance. Three path-following controllers are designed, where the first controller is applied on the front two axles of the vehicle, while the rear two axles are fixed. The second is applied to all-wheel steering vehicle. The third controller is an integration between the designed front steering path-following controller and a developed lateral stability active rear steering controller. Eventually, a series of virtual maneuvers are performed to evaluate the effectiveness of the intended controllers to present the advantages and limitations of each controller at different driving conditions.

GNSS/INS/ODO/wheel angle integrated navigation algorithm for an all-wheel steering robot

To suppress the positioning error of wheeled robots in global navigation satellite system (GNSS) denial environments, kinematic constraints should be fully utilized. However, many wheeled robots have independent steering mechanisms for each wheel to move more flexibly, which do not meet the nonholonomic constraint in the vehicle frame. Hence, the conventional GNSS/inertial navigation system (INS)/ODO (odometer) integrated navigation algorithm (GIOW algorithm) is no longer suitable. We propose a GIOW algorithm to meet the need for all-wheel steering robot positioning. In the proposed algorithm, odometer speed and wheel angle are employed together to construct a kinematic constraint for wheeled robots, which can constrain the rapid drifting error of INS. Moreover, the odometer scale factor and wheel angle error are augmented into the error state of the extended Kalman filter to be estimated and compensated online. Field tests were carried out in an open-sky environment with a wheeled robot, which can run in both corner steering mode and all-wheel steering mode. The experimental results showed that the proposed algorithm can be applied to not only the corner steering motion model but also the all-wheel steering motion model. The accuracy of the proposed algorithm was almost the same as that of the conventional GNSS/INS/ODO algorithm in the corner steering motion model. In the all-wheel steering motion model, the accuracy of the proposed algorithm was maintained.

All-electric City Buses with All-wheel Steering

All-electric City Buses with All-wheel Steering

Design and Fabrication of Four-Wheel Steering System for Efficient Transportation Systems

Automobile industry is one of the most important segment for a country’s growth. India facing its own challenges due to its huge and varied transport sector. These challenges may overwhelmed by using energy efficient advancements with the customer focused approach. The driver always driving the automobile with sophisticated technologies and should feel very comfortable. Automobile moving higher than the cruising speeds stability of the vehicle is the key factor. In four-wheel navigation system the tail wheels turning opposite to the forward-facing wheels while vehicle moves at high speeds instability chances are more. To avoid this instability rear wheels follows the same track of the forward-facing wheels while tuning of the all-wheel steering system. This paper focusing light on to the difficulty faced when all wheel steering system taking a turn in a very confined space. By switching from two wheel steering to four wheel steering owing to this the driver on the way to make turns in small radius. It also laidback for parallel parking and maneuvering the vehicle quite with no trouble on highways. In command to succeed this, a mechanism established with the two bevel gears and intermediary shaft, which transfer 100% rotating force as well turns tail wheels in out of period. The spiraling radius of the automobile with two steering wheel system is 4400 mm after switching to four-wheel steering system radius is 2596mm only. Hence, radius reduced to 1804 mm.

MODERN TENDENCIES OF AGRICULTURAL TRACTORS

It is noted that the main components of the quantitative evaluation of the performance of tractors are the indicators of their energy saturation and universality. The key characteristic of tractors of agricultural purpose is the traction class, which characterizes, first of all, the energy saturation of a tractor. Universality of agricultural tractors is characterized, mainly, by their maximum speeds of movement and average speeds of performance of transport works. It has been established that the most important directions for the development of the design of agricultural tractors are based on increasing their productivity. Increasing productivity is achieved by increasing both energy saturation and versatility, which allows to increase the time of continuous operation and the coefficient of using the tractor. It is determined that the increase in energy saturation is ensured by increasing the power of the power unit of wheeled tractors to 600 hp, as well as the addition of model series with new-level caterpillar tractors, closely aligned with wheel-type models of similar power. At the same time, the leading manufacturers of tractors are performing research and development in the development of the concept of an agricultural tractor with an engine of more than 500 hp. The increase in the universality of tractors is accompanied by the development of their construction, which ensures an increase in the maximum and average speeds of movement. The increase in transport speeds of up to 50–60 km/h and more is achieved by the improvement of stepped gearboxes, the development and introduction of continuously variable transmissions, the use and improvement of the characteristics of the suspension of the front driving axles, the cabin and the operator’s seat, the use of brakes of the front driving axle wheels, anti-lock and anti-traction systems, and all-wheel steering. It is shown that to increase the technical level of tractor equipment, great attention is paid to improving the operator’s working conditions, including by improving the design, improving the ergonomic and aesthetic properties of the cabins, automating work processes by developing and implementing on-board electronic control systems, diagnostics and controls. To reduce costs and increase the efficiency of agricultural production, the use of precision farming systems is becoming increasingly widespread.

MPC-based approach to optimized steering for minimum turning radius and efficient steering of multi-axle crane

In a conventional steering system for a multi-axle crane, the steering angle of each axle is determined according to Ackermann’s steering principle, which minimizes the slip angles of the tires. The role of optimal steering control in improving a driver’s steering efficiency is hardly considered in Ackermann’s principle. To address this problem, this paper proposes a control strategy for determining the optimal steering angles for a multi-axle crane and thereby improving a driver’s steering efficiency by applying the model predictive control (MPC) algorithm and defining a driver’s intentions. A simplified crane model for the steering system was developed using a bicycle model, and a comparative study was carried out via simulation to analyze steering performance for the conventional (Ackermann) and proposed steering control systems for the cases of all-wheel steering and road steering modes. The simulation results show that both the minimum turning radius and the driver’s steering effort are decreased more by the proposed steering control system than by conventional system and that the proposed control strategy therefore yields better steering performance.

Multibody dynamic analysis of a duplicate bimodal tram

This study aimed to dynamically analyze a simulated bimodal tram by determining the motion equations for computer-aided analysis with Newton-Euler equations of motion, which algebraically represent motion. We utilized the multi-body dynamics analysis program, MSC.Adams, to evaluate the equations of motion, running stability, curving performance, and ride comfort of the simulated bimodal tram in comparison with single fleet and double fleet trams. For the double fleet tram, the characteristic equation was deduced to control the all-wheel steering mechanism by independently moving all the wheels characterizing an articulated vehicle. Our study aimed to design a double fleet bimodal tram. We confirmed that domestic and international standards were satisfied via the design and analysis of the simulation. Steering control equations are the significant preliminary data for coupling device research and development for double fleet bimodal trams.

Localization Based on Magnetic Markers for an All-Wheel Steering Vehicle.

Real-time continuous localization is a key technology in the development of intelligent transportation systems. In these systems, it is very important to have accurate information about the position and heading angle of the vehicle at all times. The most widely implemented methods for positioning are the global positioning system (GPS), vision-based system, and magnetic marker system. Among these methods, the magnetic marker system is less vulnerable to indoor and outdoor environment conditions; moreover, it requires minimal maintenance expenses. In this paper, we present a position estimation scheme based on magnetic markers and odometry sensors for an all-wheel-steering vehicle. The heading angle of the vehicle is determined by using the position coordinates of the last two detected magnetic markers and odometer data. The instant position and heading angle of the vehicle are integrated with an extended Kalman filter to estimate the continuous position. GPS data with the real-time kinematics mode was obtained to evaluate the performance of the proposed position estimation system. The test results show that the performance of the proposed localization algorithm is accurate (mean error: 3 cm; max error: 9 cm) and reliable under unexpected missing markers or incorrect markers.

Research on all-wheel steering control strategy for the three-wheel forklift

Taking the steering performance of all-wheel steering system for the three-wheel forklift as the research object, based on a 2-dof model of three-wheel steer-by-wire system, two kinds of control strategies are proposed in this paper, one with front and rear isometric reverse rotation, and the other with yaw rate feedback. According to actual data of the forklift TFC20, the simulation analyses of the steering performance of all-wheel steering system for the three-wheel forklift is given. Compared with the conventional steering control method, the simulation results show that the first control strategy improved the steering flexibility, and the second control strategy improved the steering stability.

Modelling and optimisation of an 8 × 8 heavy duty vehicle's hydro-pneumatic suspension system

In this paper, modelling of the hydro-pneumatic suspension (HPS) system of a heavy duty vehicle that has all-wheel steering and driving capability is studied. The prototype vehicle of concern is a mobile telescopic crane. The spring and damper effects of the HPS, which is used generally in heavy commercial vehicles and in military vehicles, have been modelled separately. First, HPS dynamics is studied on 1/8 vehicle model and then vehicle dynamics is examined on the MSC ADAMS/Car model. HPS of the prototype vehicle is assessed by some objective functions. In addition, simulation-based optimisation is performed using a 1/8 vehicle model. Various designs are obtained and their performances are compared with that of the prototype vehicle's HPS by the ADAMS/Car model simulations. Modelling and optimisation studies reveal a sound background to improve the prototype vehicle and to design active HPS system.

Research on the Steering Character for Kiloton all Terrain Crane

Based on the two degree of freedom model of kiloton all-terrain crane, he effects of relationship of deflection angle on turning radius were investigated in multi-axle steering system. MATLAB/Simulink was used to analyze the relationship of every axle in multi-axle steering and optimize the minimum turning radius. The studies show that the kiloton all-terrain crane adapted all-wheel steering driving at 5speed , and the front wheel angle was 32.3°, as compared to the rolling radius before optimization, the turning radius in all wheel turnaround reduced by 33%, which improved the vehicle capacity through the complex curve and increased the vehicle steering flexibility.

전 차륜 조향 시스템 전자 제어 장치의 스윙 아웃 억제 알고리즘 개선에 대한 연구

All-wheel steering (AWS) system is applied to articulated vehicles to reduce turning radius. The swing-out suppression algorithm is applied to AWS ECU, a key component of AWS system. The swing-out suppression algorithm applied to AWS ECU has a problem when velocity of vehicle is changed. In this paper, new algorithm based on moving distance that solve velocity problem is proposed. The HILS simulation and the test articulated bus is used to validate algorithm.

Optimal Control for Three-Axle Vehicle's All-Wheel Steering

In order to develop fieldwork car’s dynamic stability, a new control system for three-axle vehicle’s all-wheel steering is put forward. A nonlinear three degree of freedom (3-DOF) all-wheel steering model is built. The tire’s magic formula and the tire vertical load’s solving method based on displacement are applied to the model and the ideal yaw rate is given. Using feedforward and feedback control algorithm, a zero sideslip angle proportional feedforward and optimal feedback control system is designed. The system is simulated on MATLAB/Simulink platform and results show the vehicle’s dynamic stability is obviously developed.

The Analysis of Steering Angle for Multi-axis Vehicle Based on Wheel Pure Rolling Condition

The all-wheel steering geometry model of multi-axis vehicle is established and the formulas of steering angles are derived in this article. Based on pure rolling condition of vehicle wheels, The instantaneous rotation center is determined by the inner steering wheel angle of the front shaft and last shaft.It is the inner steering wheel of the front shaft that is uesd as the active steering wheel . And then the rest steering wheel angles are determined by the geometric conditions of movement. In this way, the steering angle expressions of each wheel of the multi-axis vehicle are derived. A visual simulation is done by using MATLAB to draw the images at every moment of steering process. From the images, it can be seen that all vehicle wheels rotate around the same instantaneous center. The above models and formulas lay a theoretical foundation for all-wheel pure rolling steering of multi-axis vehicle.