Steering System Research Articles

A Bargaining Game-Based Human–Machine Shared Driving Control Authority Allocation Strategy

Research on game-based human-machine shared driving (HMSD) has traditionally been constrained by stringent game theory assumptions, high requirements for automated steering controllers, and the need to acquire the human driver’s target trajectory. To address these issues, this paper proposes a bargaining game-based HMSD control authority allocation strategy for a steer-by-wire vehicle. First, two types of lateral path tracking controllers are developed to simulate the human driver and the automatic steering system. Then, a bargaining game-based HMSD control authority allocation strategy is created using the Nash bargaining solution. Finally, a Simulink/CARSIM co-simulation platform and a driver-in-the-loop experimental bench are utilized to verify the proposed strategy. The results show that the proposed bargaining game-based HMSD control authority allocation strategy has potential advantages over existing game-based HMSD, including decoupling of human-machine interaction, lower requirements for automated steering controllers, and feasible game modeling ability. Moreover, the proposed strategy demonstrates excellent performance in terms of shared driving, which extends the applicability of HMSD in various operating maneuvers. Both the human driver and the automatic steering system benefit from the proposed HMSD system, which could increase the acceptance and trustworthiness of the human driver with the HMSD system and reduce the human driving load to make the driver-vehicle interaction more reliable and smoother.

Boosting output performance of tri-hybrid vibration-based generator via quin-stable nonlinearity and speed amplification

A high-performance tri-hybrid vibration-driven generator with quin-stability and speed amplification characteristics is presented. This design integrates three different mechanisms in a compact and interactive working mode to enhance power density. Exploiting the quin-stable nonlinear behavior to the dynamic system creates a shallow potential well that can be triggered under broadband, low-level, and random ambient sources. In addition, the implementation of the rack and pinion steering system not only doubles the relative motion of the translators’ moving components in the electromagnetic and triboelectric units, and also increases the number of operations per cycle of the frequency up-conversion piezoelectric units. Consequently, the output performance of this tri-hybrid generator is significantly enhanced. To examine the working efficiency of this design, an experimental model is assembled and tested. In the shaker test, the peak output power of the prototype can be boosted to ∼822 mW, and the maximum power density is 7.74 mW cm−3 g−2 subjected to low excitation levels (5 Hz and 1-g acceleration). Experimental demonstrations are also carried out to exhibit the exceptional performance of this design that can support various power levels of electronic devices under human-induced motions.

Enhancing Autonomous Vehicle Lateral Control: A Linear Complementarity Model-Predictive Control Approach

Model-predictive control (MPC) offers significant advantages in addressing constraint-related challenges and plays a pivotal role in self-driving car technology. Its primary goal is to achieve precise trajectory tracking while prioritizing vehicle stability and safety. However, real-time operations often face challenges related to computational demands and low computational efficiency. To address these challenges, this paper introduces a novel lateral control algorithm for self-driving vehicles, which utilizes the linear complementarity problem (LCP) instead of the conventional quadratic programming (QP) method as the MPC optimization solution. This innovative approach incorporates the electric steering system into the vehicle dynamics model, allowing for precise torque regulation of the steering motor and enhancing control accuracy. The MPC algorithm adopts the LCP solution method to calculate control signals based on the vehicle’s state, ensuring both rapid and stable vehicle control. Simulation results demonstrate that the proposed MPC algorithm, utilizing the LCP solution method, effectively addresses efficiency issues in the lateral motion of self-driving cars. This leads to improvements in both driving stability and real-time performance. Overall, this innovative approach lays a solid foundation for the practical implementation of self-driving cars.

Development and evaluation of 4WSS electric-driven chassis for high-clearance sprayer.

The high clearance sprayer with conventional steering mechanisms, as an intelligent spraying machine, is frequently stuck or broken in muddy fields due to the excessive torque load. A Four-Wheel Self-Steering (4WSS) electric-driven chassis with a smaller turning radius and better passability is developed to handle complex agricultural terrains. The 4WSS chassis is mainly composed of two custom-designed steering bridges and four in-wheel drive motors. It can achieve steering and driving forward simultaneously through coordinate differential speed control of drive motors, saving a set of dedicated servo steering systems and requiring less torque during steering compared to conventional structures. A kinematic model depicting the speed relationships between four wheels is established via geometric analysis, and a Speed Distribution Controller (SDC) is designed to accomplish locomotion objectives. Experimental results demonstrate the effectiveness of the new prototype 4WSS chassis system in tracking speed and steering angle. Compared to conventional agricultural chassis, the 4WSS chassis has a smaller turning radius of 2,877 mm. The 4WSS chassis exhibits superior performance in typical field conditions, including muddy terrain, deep gullies, and ridges.

Dynamic Testing of In-Wheel Motor Based Electric Vehicle in Longitudinal Direction

This paper presents an investigation into the performance of in-wheel motor (IWM) based electric vehicles (IWM-EV) in the longitudinal direction. The design of IWM-EV is an innovation of the conventional go-kart vehicle with slightly modifications in steering, suspension, and braking system, which then makes use three-phase permanent magnet synchronous in-wheel motor (PMSM-IWM) at both of the rear axle wheels. An extension of that is a simulation of IWM-EV vehicle using a 5-degree-of-freedom vehicle longitudinal model that has been developed by incorporating PMSM-IWM as a drive wheel located at the rear axles. Using the simulation, vehicle dynamic control in the longitudinal direction-based Proportional-Integral-Derivative (PID) controller has also been strategized. As the intention to confirm the capability of the IWM-EV, experimental studies-based real IWM-EV hardware have been conducted. Three dynamic tests that generalized from SAE standard SAE J866-199908, namely acceleration performance at the level pavement (include acceleration tests and acceleration then braking tests) and road gradient tests at constant speeds of 10, 15 and 20 km/h, were used as the testing method. The performance areas evaluated were vehicle body speed, wheel speed, distance travel experienced by the vehicle, IWMs current, drive torque as well as the battery voltage capacity used by the vehicle. The finding indicate that the simulation results and experimental data are similar with less than 5 % error. The outcomes from this study will be considered in the design optimization of a torque vectoring control in the next research study.

Vertical-cavity surface-emitting phase shifter.

This study proposes a novel technique for a 2D beam steering system using hybrid plasmonic phase shifters with a cylindrical configuration in a 2D periodic array suitable for LIDAR applications. A nanoscale VCSEP design facilitates a sub-wavelength spacing between individual phase shifters, yielding an expanded field of view and side lobes suppression. The proposed design includes a highly doped sub-micron silicon pillar covered by a thin layer of nonlinear material and an additional conductive metal layer. Characterization of a single VCSEP demonstrated a Free Spectral Range (FSR) of 53.28 ± 2.5 nm and a transmission variation of 3 dB, with VπL equal to 0.075 V-mm.

Sensitivity analysis of inverse multilateration based on tracking interferometer measurement for a bi-rotary head five-axis machine tool

This paper proposes a novel inverse multilateration that improves the accuracy by sensitivity analysis and calibration of rotary axes’ position-independent geometric errors. In recent years, the tracking interferometer measurement with inverse multilateration has been widely adopted in the assessment and compensation of the five-axis machine tool. It uses the bi-rotary head as the steering mechanism to reduce cost, which also introduces errors from rotary axes. In this paper, a sensitivity analysis for position-independent geometric errors of rotary axes is proposed to reveal the error propagation mechanism and identify the main error sources. An optimization for the number and distribution of measured points is investigated based on the result of sensitivity analysis. Monte Carlo simulations and experiments are carried out on a bi-rotary head five-axis machine tool to verify the proposed method. The results show that the accuracy and efficiency of inverse multilateration measurement have been significantly improved.

Design of Active Disturbance Rejection Controller for Trajectory-Following of Autonomous Ground Electric Vehicles

In this paper, the concept of symmetry is utilized in the promising trajectory-following control design of autonomous ground electric vehicles—that is, the construction and the solution of active disturbance rejection controllers are symmetrical. This paper presents an active disturbance rejection controller (ADRC) for improving the trajectory-following performance of autonomous ground electric vehicles (AGEV) with an advanced active front steering system. Since AGEV trajectory dynamics are inherently affected by complex traffic conditions, various driving maneuvers, and other road environment, the main control objective is to deal with the AGEV trajectory control challenges of system uncertainties, system nonlinearities, and external disturbance. First, the vehicle dynamics trajectory-following model and its state space representation system are established. Then, the augmented control-oriented vehicle-trajectory-following system with dynamic error is developed. The resulting active disturbance rejection controller of the vehicle-trajectory-following system is finally designed using the trajectory performance index and active disturbance compensation, and the stability of the active disturbance rejection controller is also analyzed and derived via Lyapunov stability theory. The effectiveness of the proposed controller is validated through double lane change and serpentine maneuvers under the co-simulation platform of MATLAB/Simulink-Carsim®. Simulation results show that the designed controller provides enhanced vehicle-trajectory-following performance compared to the linear quadratic regulator controller (LQR) and model predictive controller (MPC). It will provide a certain guidance for the controller engineering design of the AGEV trajectory-following system.

The Hidden Power of Sustainable Tourism Indicator Schemes: Have We Been Measuring Their Effectiveness All Wrong?

Evaluating whether sustainability indicator schemes contribute to better sustainable destination management has proven challenging. We adopt a systems thinking approach to shed light on the elusive impacts of sustainable tourism indicator schemes. We conduct online participatory workshops with 19 experts in sustainable tourism monitoring, to produce a causal loop diagram that illustrates how destination systems behave when indicator schemes are implemented. The results show that until now, these schemes have been expected to follow utopian, evidence-based, policy pathways to change, but we now understand that this linear-thinking approach fails to recognize the complex interplay of factors that occur during implementation. We find that indicator schemes can spark a rich, yet unappreciated, series of conceptual, instrumental, and structural dynamics. We conclude that the hidden power of these schemes lies in their ability to foster dialog, stimulate learning, incentivize network development, challenge stakeholder worldviews, and steer systems change toward sustainable destination management.

A Geometric Model for a Shield TBM Steering Simulator

This study aimed to simulate curved excavation using a tunnel boring machine (TBM) steering system based on the proposed mathematical methodology applied in a TBM simulator. We introduce the concept and mechanism of the TBM steering system and describe the mathematical formulae used for simulating curved excavation. Curved excavation in the top- right direction was simulated using a Python program to verify the mathematical formulae. In addition, Python simulations were undertaken to determine the effects of horizontal and vertical articulation angles on pitching and yawing angles. Finally, the proposed mathematical formulae were applied in the TBM operation simulator, and tested based on the mechanism of the TBM steering system.

Research on Differential Steering Dynamics Control of Four-Wheel Independent Drive Electric Tractor

Traditional tractors can only achieve steering through mechanical structures such as steering knuckles and steering trapezoids. Among them, the mechanical structure is more complex, and various parts are easily damaged, making the tractor malfunction. The four-wheel independent drive differential steering mode differs from the traditional Ackermann steering mode, which realizes steering by controlling the inner and outer wheel torque, which can accurately steer the working state of high-end agricultural machinery equipment and improve the operating efficiency of agricultural machinery equipment. Aiming at the dynamic control problem in the steering of electric tractor four-wheel independent drive, a layered control strategy based on the sliding mode control of yaw torque at the upper level and the optimal torque distribution level based on the mean load rate of vehicle tires at the lower was proposed. By analyzing the differential steering mechanism of a four-wheel independent drive, a dynamic model of differential steering of the electric tractor is established, and a dynamic controller of a four-wheel independent drive is designed according to the layered control strategy. The upper controller tracks and controls the expected yaw speed on the basis of the sliding mode control to track the driver’s intention, and the lower controller realizes the optimal torque distribution based on the principle of the optimal average load rate of the vehicle tire to ensure the steering stability of the electric tractor. The effect of the controller was simulated and analyzed under typical conditions of double line shift, serpentine, and step. The results showed that the sliding mode controller is better than the PID controller in driver intention tracking. Compared with the average allocation strategy, the average maximum load rate of the vehicle tire under the three working conditions is reduced by 16.9%, 13.8%, and 17.3%, respectively, which proves the effectiveness of the layered control strategy. In the real car test, the sliding mode controller is better than the PID controller in the driver intention tracking. This study has important guiding significance for improving the maneuverability and stability of electric tractors.

Semi-automatic of steer by wire system using fuzzy logic control and swarm optimization

<span lang="EN-US">The semi-automatic steer by wire system is a vehicle steering system that does not use a mechanical link but uses an electric drive, so that the steer wheel is equipped with an angle sensor as a control system input to adjust the electric drive rotation when determining the direction of the front wheels of the vehicle. The control system uses fuzzy logic control (FLC) is optimized using swarm-based optimization. Performance testing of the optimal control system is carried out using Software in the loop simulations and hardware in the loop simulations which were then applied to the steering system prototype equipped with rack-pinion and wheel steer. The test results show that the optimal control system performance reaches a C-RMS error of 6.712. The prototype that was built has two kinds of ratios between the steering angle and the vehicle wheel angle, namely a ratio of 1:6.25 for speeds below 10 km/h making it suitable for operation when the vehicle is maneuvering in the parking area and a ratio of 1:25 for speeds above 10 km/h which is suitable for operation when the vehicle is traveling at medium or high speed.</span>

Adaptive Position Control Strategy of SRM-Based EMA System for Precision Position Tracking

The electromechanical actuator (EMA) driven by switched reluctance motor (SRM) is promising to be used in the steering vane control system on the landing craft air cushion (LCAC) hovercraft due to its reduced maintenance costs and increased control flexibility. However, the system parameter uncertainty, the unknown load disturbance, and the large torque ripple of SRM make it challenging to achieve high position control precision. To improve the position control accuracy of the SRM-based EMA system, an adaptive position control strategy is proposed in this paper. Firstly, an adaptive fast terminal sliding mode controller (AFTSMC) is designed to address the issues of model parameter estimation and load disturbance rejection, which improves the dynamic response performance of the SRM-based EMA system. Secondly, a current-limited direct torque controller (CL-DTC) is proposed to track the reference torque calculated by AFTSMC with lower torque ripple and to limit the excessive currents of SRM at the same time, which helps further enhance the position control precision and prevent the SRM-based EMA from overheating. Finally, the proposed position control strategy is tested and compared with other three position controllers based on simulations and experiments. The results demonstrate the effectiveness and superiority of the proposed position control strategy.

A novel dual power-driven electric power steering system for electric commercial vehicles

To solve the power limitation problem faced by the development of EPS system for commercial vehicles and achieve the high-performance steering, this article presents a novel dual power-driven electric power steering system (DPEPS) for commercial vehicles by using the open winding permanent magnet synchronous motor (OPMSM) fed by dual inverter with high and low DC voltage supplies. First, the two-level control strategy is introduced for the developed DPEPS system, where the upper control is designed to make the actual steering follow the expected steering performance as determined by the assistant torque curve and to generate the appropriate target current according to the vehicle speed and steering torque. And then the lower control consists of the synthetical space vector control scheme and dual PI control loop is used to execute commands from the upper control, which can make the motor execute the appropriate power supply method according to the steering torque and assist current. Finally, a co-simulation model is carried out for an electric bus, and based on which the proposed DPEPS system is validated.

DEVELOPMENT OF THE STAND FOR EXPERIMENTAL RESEARCH OF THE DOSER PUMP OF THE HYDROSTATIC STEERING SYSTEM OF SELF-PROPELLED AGRICULTURAL MACHINERY

Hydrovolumetric steering systems have today become widely used in heavy agricultural machines, such as combines, loaders, etc. The reliability and quality of operation of these machines largely depends on the quality of these systems and their elements. During the operation of these systems, a number of shortcomings were identified, which require additional research and the application of new design solutions. From the analysis of modern developments of the leading manufacturers of elements of these hydraulic systems, it follows that the main design changes are caused by the need to ensure the operability of these systems in abnormal or emergency situations. To check the performance of these devices in laboratory conditions, it is necessary to provide bench equipment with the ability to simulate abnormal situations and ensure the recording of the received information for the purpose of its further analysis and the formation of a set of measures aimed at eliminating the identified deficiencies and meeting the requirements of current standards. The authors have developed an original method of experimental research of individual steering control units for hydrostatic steering systems of special vehicles. It is proposed to create a load on the steering control unit in the form of a pressure difference in its output channels without using supporting hydraulic cylinders. To implement the proposed method, an electro-hydraulic scheme of the stand was developed. This makes it possible to analyze the quality of the steering unit's operation in conditions corresponding to different operating modes of the steering system, and to determine the corresponding characteristics of the steering unit under oncoming and passing loads.

Mitigation of greenhouse gas emissions in pasture-based dairy-beef production systems

CONTEXTAgriculture and food systems contribute significantly to climate change. Greenhouse gas (GHG) emissions intensity from beef production are high when compared to other livestock production systems and, therefore, mitigation of these emissions is urgently required. In many countries dairy-beef is making a large and growing contribution to total beef output thereby reducing net emissions given the lower emissions intensity of beef originating from the dairy herd when compared to specialized beef-cow systems. GHG emissions from dairy-beef systems can be further reduced by adopting best practice and mitigation technologies. OBJECTIVESThe objectives of this study were to (1) evaluate a range of management practices to reduce GHG emissions for pasture-based beef cattle production systems, (2) model the individual and combined impacts of these management practices on GHG emissions from dairy-beef systems, and (3) identify any trade-offs between GHG emissions mitigation, farm profitability, food security and land use. METHODSA farm level bioeconomic systems model was modified to evaluate spring-born, steer production systems finishing cattle at differing slaughter ages and from contrasting forage-based finishing diets (grazed grass or grass silage, each supplemented with concentrates). Mitigation measures included earlier slaughter age, optimal slurry management, urease inhibitors for nitrogen (N) fertilizers, replacing cereals with ‘by-products’ in concentrate feed rations and incorporating clover in grassland pastures. RESULTS AND CONCLUSIONSCombining mitigation strategies reduced dairy-beef systems GHG emissions intensity by an average of 21%. Incorporating clover in grassland pastures was found to be the most profitable stand-alone mitigation strategy increasing net margin by an average of 18%. Substituting by-products for barley in a concentrate ration converted all systems into net producers of human edible protein; otherwise, steer systems finishing at pasture during the third grazing season were the only net producers of human-edible protein. However, finishing at pasture during the third grazing season increased GHG emissions per animal and per kilogram of beef carcass. SIGNIFICANCEWithin a grass-based dairy-beef system, such as that modelled in this study, a number of complementary GHG emissions mitigation strategies can be implemented, without making substantive changes to the production system, while simultaneously improving farm profitability.

Understanding long-term thinking as a management strategy to support sustainable quality development: perspectives from education

PurposeThe purpose of this study is to explore the concept of long-term thinking in a non-business context to gain deeper insights into bridging the gap between the theory of long-term thinking and its application as a management strategy.Design/methodology/approachTo explore the concept of long-thinking further in a non-business setting, a grounded theory study was conducted with preschool leaders in a municipality in Sweden to examine how the leaders describe, define and apply the concept of long-term thinking in their schools. Interviews with school leaders, both written and oral, were used for data collection.FindingsThis study illustrates that the concept of long-term thinking can be twofold. First, the description can be as an anchor that reflects a mission. Second, the description can be a steering mechanism that guides decision-making. The findings also reinforce the importance of organisations developing an organisational culture that connect their vision and goals with the values and needs of their customers.Research limitations/implicationsThis study was carried out in a single organisation and shows a snapshot of the organisation's status at the time the data were collected. Therefore, the findings are not generalisable to all organisational settings; rather the findings may be transferable to other settings.Practical implicationsThe results can be used to help identify areas where preschools in a municipal context can engage with sustainable quality development in order to build systems that support work with quality in a more structured way.Originality/valueLong-term thinking is seen, within both theory and organisations, as necessary to achieve success in terms of sustainable development and quality, and this study contributes with knowledge about the current gap between theories of long-term thinking and practice in organisations.

Research on active disturbance rejection control strategy of electric power steering system under extreme working conditions

In response to the influence of motor interference, damping, friction, and other uncertain factors on the operation of electric power steering systems under extreme working conditions, this study proposes a control strategy for electric power steering systems based on an active disturbance rejection algorithm. In ADRC, the fastest tracking differentiator is used to arrange the transition process for the target signal, and the extended state observer compensates for the total disturbance in the system. Phase compensation has been performed on the monitoring torque by using the torque differentiation method. The Simulink/Carsim simulation results show that ADRC has significantly improved anti-disturbance performance compared to PID and fuzzy PID. When using ADRC, the tracking accuracy of the assisted current is enhanced by 45.8%–75.8%, and the current adjustment time is reduced by 35.6%–61.7%. After phase compensation, the monitoring torque overshoot is reduced by 83.3%. Therefore, the proposed control strategy improves EPS’s robustness and steering feel.

Utilizing Dynamic Analysis in the Complex Design of an Unconventional Three-Wheeled Vehicle with Enhancing Cornering Safety

Current trends in the transportation industry prioritize competitive rivalry, compelling manufacturers to prioritize concepts such as quality and reliability. These concepts are closely associated with public expectations of safety, vehicle lifespan, and trouble-free operation. However, the public must recognize that a vehicle weighing several hundred kilograms, moving at a non-zero speed, only contacts the road surface through a few points (depending on the number of wheels), each no larger than a human palm. Therefore, it is imperative to operate the vehicle in a manner that optimizes the behavior of these contact points. There are situations where drivers find themselves requiring dynamic vehicle handling, often unpredictable with a high degree of uncertainty. Rapid changes in direction become necessary in these cases. Such maneuvers can pose a significant risk of rollover for three-wheeled vehicles. Hence, the vehicle itself should contribute to increased ride safety. This paper presents key findings from the development of an unconventional three-wheeled vehicle utilizing the delta arrangement. Rollover safety for three-wheeled vehicles is currently well-managed, thanks to the utilization of electronic or mechatronic systems in delta-type vehicles to enhance stability. However, these systems require additional components. In contrast, the proposed control system operates solely on a mechanical principle, eliminating operational costs, energy consumption, maintenance expenses, and similar factors. The study also explores the absence of equivalent suspension and steering systems for front-wheel steering. Such designs are lacking in both practical applications and theoretical realms. Analytical and simulation calculations are compared in this study, highlighting the effectiveness of the newly proposed control system in enhancing stability and safety compared to conventional front-wheel suspension systems. Simulation programs provide more realistic results than analytical calculations due to their ability to account for dynamic effects on vehicle components and passengers, which is practically unfeasible in analytical approaches. Furthermore, this study focuses on investigating the fatigue life of material frames subjected to dynamic loading, which is a crucial aspect of ensuring safety. It is essential to have various testing devices to examine the fatigue life of materials under both uniaxial and multiaxial loading conditions. However, obtaining experimental results for fatigue life measurements of specific materials, which can be directly applied to one’s research, poses significant challenges. Hence, the proposed testing device plays a vital role in measuring material fatigue life and advancing the development of unconventional transportation methods. The information about the original testing device aligns perfectly with the article’s emphasis on dynamic analysis. The ultimate objective of all these efforts is to put the vehicle into practical operation for commercial utilization.

IoT-Driven Parking System: Integrating 4WD, 4WS, And Parking Sensors for Electric Four Wheelers' Enhanced Maneuverability

Innovative automotive technologies like 4-Wheel Drive, 4-Wheel Steering, and Electric Power Steering systems can greatly enhance a vehicle's performance, stability, and handling. These technologies are commonly found in high-end vehicles due to their ability to improve traction, maneuverability, and steering accuracy. A sophisticated system utilizing a combination of advanced sensors, electronic controls, and mechanical components would enable each wheel to turn independently of the others. Such a system could provide even better handling, stability, and traction in challenging driving situations. The integration of independent wheel turning mechanisms, 4-Wheel Drive, 4Wheel Steering, and Electric Power Steering has the potential to transform the automotive industry, offering enhanced safety and efficiency in addition to providing an enjoyable driving experience, making it more appealing to drivers.