Novel tactile perception device for torque feedback in SBW using magnetorheological fluid

The increasing of population in urban area causing a drastic number of vehicle appears on the road. Besides of contributing a negative impact for surrounding environment due to CO2 gas emission, it is also causing a difficulty and reduce flexibility of people to move in short distance. In this paper a development of electric vehicle for urban usage is presented. The design of this electric vehicle involves mechanical structure, electronic module and control algorithm development. This two seated vehicle is equipped with Four Wheel Independent Steering (4WIS) system that is controlled using Steer by Wire (SBW) technology and the drive unit is using the state of art In-Wheel Drive electric DC motor (IWM). Result shows that, this Compact Electric Vehicle (CEV) can improve maneuverability during tight cornering angles by using All Wheel Steering (AWS) mode and also capable to perform a motion of 180∘ turning or Zero Point Turning (ZPT). The system architecture is proposed to integrate 4WIS with SBW.

Steer-by-Wire (SbW) system is an advanced steering system where the conventional mechanical linkages between the steering wheel and the front wheels are removed, and replaced by electric actuators. Due to no direct mechanical linkages, accurately controlling the front wheels to track the movement of the steering wheel is becoming critical for the steering system performance. To reduce the effects caused by the nonlinear friction torque and alignment torque to the tracking performance of the SbW system, a Takagi-Sugeno (T-S) model is proposed to describe the nonlinear dynamics of the SbW system in this paper first. A fuzzy tracking controller is then designed to track the reference signal, and the H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> tracking performance is guaranteed for a prescribed level under external disturbance and reference signal. The linear matrix inequality convex programming technique is used to obtain the fuzzy controller with the guaranteed H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> tracking performance. The simulation results are presented in support of the performance and effectiveness of the proposed control scheme.

In a steer-by-wire (SBW) system in a passenger vehicle, the conventional mechanical linkage between the steering wheel and the front wheel is replaced by electric wires. The SBW system consists of two parts: the steering-wheel system and the front-wheel system. The front-wheel system is the rack-actuating type. This paper proposes a concept for the control of the rack-actuating SBW system. In particular, the controller should behave similarly to a conventional (mechanically linked) steering system. In this paper, the rack-actuating SBW system was modelled using the bond graph method. The actuator controller was designed to minimize the reference signal error. The current research also considers the improvement in steering feel using feedback control of road information, in which the steering-wheel system's control algorithm used the torque map and transfer information of the road to the driver. Verification simulation and performance simulation showed that the rack-actuating SBW controller was available in this paper.

This study proposes a new control system to enhance directional stability of small-scale electric vehicle by Steer-by-Wire (SBW) System. SBW has structure merits in avoiding interference between the driver and steering wheel since mechanical link between steering wheel and tire is replaced by electric wire system, consisting of sensors, steering actuators and controllers. To enhance stability against disturbance, steering control algorithm of SBW is proposed by using theory of disturbance observer. To improve straight-running stability, the controller is designed to regulate the yaw rate generated by asymmetric braking on μ-split road. The effectiveness of the proposed SBW is verified by computer simulation. Finally, the on-board system of experiment vehicle is introduced.

A four-wheel steer-by-wire vehicle (FSV), which is a combination of a steer-by-wire (SBW) system and a four wheel steering (4WS) system, not only can improve vehicle safety and maneuverability, but also steering flexibility. Considering the parameters, uncertainties of vehicle speed, and tire cornering stiffness, weighted function is solved to express the uncertain system. Aiming at the multiple-input multiple-output (MIMO) system, the structured singular value $\mu $ is used to research FSV under multiple perturbations in this paper. Based on $\mu $ control strategy, $\mu $ controller is designed to track the desired sideslip angle and yaw rate. Thus, the vehicle gets better performance. Compared with SBW and 4WS systems, FSV has better state response under steering angle step input simulation experiment. The advantages of $\mu $ control compared with $H$ ∞ control on FSV have been explained in the simulation experiments. Furthermore, experiment results show that the designed controller can make the vehicle well track the reference model and improve the vehicle maneuverability.

In this paper, tactile response characteristics in medical haptic interface are investigated to characterize the feeling of contact between the finger skin and the organic tissue when a finger is dragged over tissue. In order to represent the tactile feeling, a prototype tactile display incorporating Magneto-Rheological (MR) fluid has been developed. Tactile display devices simulate the finger's skin to feel the sensations of contact such as compliance, curvature and friction. Thus, the tactile display provides the surface information of organic tissue to the surgeon using different actuating mechanisms ranging from the conventional mechanical motor to the smart material actuators. In order to investigate the compliance feeling of human finger's touch, vertical force responses of the tactile display under the various magnetic fields have been assessed. Also, frictional resistive force responses of the tactile display are investigated to simulate the action of finger's dragging. From the results, different tactile feelings are observed as the applied magnetic field is varied and arrayed magnetic poles combinations. This research gives a smart technology of tactile displaying.

In this paper we propose an alternate approach to improve steer-by-wire (SbW) reliability in which we utilize brake-actuated steering (BAS) as an independent secondary backup steering system. In SbW systems, component and module redundancy is the common approach used to maintain the steering function when a failure occurs. Unfortunately this adds a significant amount of complexity and cost and, what is more important, it is not possible to overcome unanticipated and common mode failures of the SbW system. BAS utilizes the torque generated by selective wheel braking and/or acceleration to actuate the steering mechanism. With this approach, if the primary steering system (SbW) fails uncovered or there is a common mode failure, the steering rack is decoupled from the primary steering actuator and the wheels are instead steered by the torque generated by application of asymmetric braking (or acceleration). BAS, as well as SbW, will be a heavy user of power electronics, electrical actuators, sensors and sophisticated control systems, many of which are already available from electronic stability systems (e.g., ESP), which are becoming more common in passenger cars. In this paper we detail the characteristics of the BAS system and provide the models necessary for designing appropriate power electronics and control systems.

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;The steer-by-wire (SBW) system, an integral component of the drive-by-wire chassis responsible for controlling the lateral motion of a vehicle, plays a pivotal role in enhancing vehicle safety. However, it poses a unique challenge concerning steering wheel return control, primarily due to its fundamental characteristic of severing the mechanical connection between the steering wheel and the turning wheel. This disconnect results in the inability to directly transmit the self-aligning torque to the steering wheel, giving rise to complications in ensuring a seamless return process. In order to realize precise control of steering wheel return, solving the problem of insufficient low-speed return and high-speed return overshoot of the steering wheel of the SBW system, this paper proposes a steering wheel active return control strategy for SBW system based on the backstepping control method. First, the dynamics model of the SBW system is established, thereby laying the foundation for further analysis. Next, an active return judgment logic based on steering wheel angle, driver torque and the change rate of driver torque to make informed decisions regarding return control is proposed. Then, the active return control algorithm based on the backstepping control method is designed and the stability analysis of this algorithm is provided to ensure its reliability in practice. At last, the effectiveness of the steering wheel active return control strategy is evaluated by simulations and hardware-in-the-loop test. The results show that the return control strategy can accurately judge the return time and have a relatively good return effect with the low-speed return deficiency and high-speed return overshoot of steering wheel be alleviated.&lt;/div&gt;&lt;/div&gt;

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Looking back on steering systems in more than a hundred years that have passed since the introduction of the automobile, it can be seen that original method of controlling cars pulled by animals such as horses was by reins, and early automobiles had a single push-pull bar (tiller steering). That became the steering wheel, and an indirect steering mechanism by rotating up and down caught on.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;While the steering wheel is the main type of steering system in use today, the team have developed the Twin Lever Steering (TLS) system controlled mainly by bi-articular muscles, making use of advancements in science and technology and bioengineering to develop based on bioengineering considerations as shown in Fig. 1. The objective of that is to establish the ultimate steering operation system for drivers.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;In the first report, the authors reported on results found by using race-car prototypes as shown in Fig. 2. Advantages in terms of bioengineering are (1) force can be exerted more easily, (2) steering can be accomplished quickly, (3) positioning can be done accurately, and (4) burden on the driver can be reduced (less fatigue). Advantages in terms of vehicle motion are (1) line-traceability is improved and (2) lap time is improved and steering layout is safe.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;Herein, creating a TLS system using prototype vehicles based on those on the market and verification test results will further be reported.&lt;/div&gt;&lt;/div&gt;

The fundamentals and preliminary analyses of an innovative future technology referred to as ‘semi-active steering’ (SAS) are presented in this article. The proposed steering system configuration is similar to a conventional electrical power-assisted steering with the replacement of the rigid steering shaft with a low stiffness resilient shaft (LSRS), the presence of which allows ‘active control’ to be performed on vehicles similar to the concept of full steer-by-wire (SBW). But, unlike SBW, the LSRS is an integral part of the system characteristics. The advantages of the semi-active system in comparison with SBW and other conventional systems are demonstrated. A mathematical model to predict the mechanical properties of the LSRS has been developed, and experiments were conducted on a medium-sized car fitted with an LSRS to verify that vehicle stability and drivability can be ensured in the event of active system failure. The results have indicated that the vehicle was stable and safe to be driven at low speeds, and is predicted to be driveable and safe at higher speeds. It is concluded that an SAS system of this type has the potential to improve the safety of SBW systems.

The Steer-by-Wire (SbW) system is an electronically controlled steering system that is able to improve steering capability without mechanical links between the steering wheel and the front wheels. However, failure of the SbW system actuator may lead to steering performance degradation and result in instability. In this paper, a fault tolerant sliding mode predictive control (SMPC) strategy for an SbW system is proposed. The sliding mode control is applied to improve the robustness of the model predictive control (MPC) in the presence of modeling uncertainties and disturbances, while the MPC is applied to enhance the fault tolerant capability of the steering control processes. The chaos particle swarm optimization (CPSO) algorithm is introduced to optimize the MPC and a two-stage Kalman filter is introduced to simultaneously provide fault information and state estimation. The performance of the proposed approach is validated through computer simulation. The results demonstrate that the proposed SMPC-CPSO controller is more robust and provides better tracking performance in the presence of model uncertainties, disturbance, and actuator faults than SCMP-PSOs (heterogeneous comprehensive learning particle swarm optimization, evolutionary particle swarm optimizer, etc), SMPC-differential evolution, MPC, SMPC, and MPC-PSO.

Lane changing is one of the crucial tasks for an autonomous vehicle to avoid an obstacle. This task can be performed by controlling the throttle, brake, and steering actuators appropriately based on the analysis of the vehicle’s surroundings. The problem with lane changing is that the control strategy is too complex and needs a high processor for real-time data analysis. In addition, lane changing involves high-level control for vehicle trajectory and low-level control for controlling the steering actuator. This study proposed a well-known method, namely Model Predictive Control (MPC), to determine the vehicle’s lateral position and yaw angle during lane changing maneuver. The optimum steering angle command can control the steer-by-wire (SBW) system from the lateral position and yaw angle in MPC. The Proportional-Integral-Derivative (PID) controller is implemented to control the steering wheel angle in the SBW’s system. Then, the SBW system will turn the wheel of the vehicle plant. From the simulation result, the PID controller can converge the error although the vehicle’s speed is increasing. The result shows that the mean absolute error (MAE) of the SBW system decreases slightly from 0.0115 to 0.0079 as the speed increase from 16 to 41 km/h. From this study, it can be concluded that the MPC and PID controllers can control the vehicle’s trajectory during lane changing by calculating an optimum lateral motion and yaw angle to provide an optimum steering angle for the vehicle to change lanes successfully.KeywordsSteer-by-wire (SBW)Model Predictive Control (MPC)PID controlLane changingAutonomous vehicle

Universitas Indonesia has developed several types of electric vehicles as conversions from conventional vehicles. Among these types of vehicles that have succeeded are city car and bus types. Electric buses currently use the ladder frame chassis system. In this chassis system there is a hydraulic steering system. In order to develop a hydraulic steering system into an electric steering system, it is necessary to study the existing mechanism of the steering system. Static analysis is a form of study of this mechanism to determine how much the forces acting on each link. The steering mechanism system on this bus has a different shape from a vehicle such as a city car. The differences include the distance from the steering wheel to the front axle is relatively far. Due to this long distance, there are many links that build this mechanism. Static force on the front wheels of 6 tons will continue to the steering wheel. Deciphering the forces between links needs to be done so that you can definitely work with each link's force. After the force of each link is obtained, the stress acting on each bar will be used for the selection of the appropriate material. The use of local materials will be simulated through CAD software to obtain the smallest safety factor produced. Shape and size simulations will be carried out in this analysis to obtain optimum results for each link in this steering mechanism. Transfer of force from the wheel to the steering rod through a six-link mechanism. The material used is S45C JIS G 4051 equivalent to local content material KS 1045. The maximum stress that occurs at the drop link extension is 190.72 MPa and at the drop link is 569 MPa.

For the problems of inaccurate parameters and steering resistance disturbance in electro-hydraulic coupled power steering (EHCPS) system of intelligent commercial vehicles, we designed a dual-loop steering system corner controller. In this paper, firstly, we analyzed the complex uncertain parameters of the EHCPS system and then simplified it to the two-degree-of-freedom control model. Secondly, we analyzed the dynamic perturbations caused by vehicle speed changes and designed a compensating loop controller to calculate the corresponding steering wheel angle. Then, we linearize the steering resistance and the hydraulic power assist and designed the closed-loop robust controller for the main loop. Finally, we simulate the front wheel angle following of the steering of intelligent commercial vehicles under different speed conditions, and the results prove that the angle following under this controller has higher accuracy and have good robustness.

Magnetorheological fluids (MRFs) include suspensions of ferromagnetic particles, medium oils, and several types of additives. Their rheological properties change rapidly, stably, and repeatedly when magnetic fields are applied. In this present study, we focus on a haptic device using MRFs. Though particle sedimentation is one of the drawbacks of MRFs, we developed an MRF using iron particles of size 10–100 µm and silicon oil (Nano-MRF); more specifically, we use this material as a working material for the haptic device. We developed a prototype of an MRF brake as a core device for haptic control. In this paper, we describe our design method for the corresponding magnetic circuit. In addition, we designed a detailed structure for the unit. We investigated the basic properties of this unit by using a test machine with two types of MRFs, i.e., our Nano-MRF and a commercial MRF. From our results, the Nano-MRF showed better stability and response times versus that of conventional materials.