Steering Angle Research Articles

Optimizing the Knuckle Corner Design of an Urban EV8 Vehicle Category Concept to Meet Turning Radius Requirements

This research aims to achieve the smallest possible turning radius for the knuckle joint while also meeting the regulations set by the Shell Eco-Marathon (SEM) committee regarding the design angles and lengths. Calculations and testing are conducted using simulation methods to obtain suitable angles and lengths for the knuckle. This simulation method involves a series of analyses to obtain data such as static turning radius diagrams, followed by an analysis using the camber calculation formula. The shape, angle, length, and design of the knuckle are considered with regard to driving safety factors. The findings of this study indicate that for a six-meter turning radius, the outer wheel requires a steering angle of δ_0=10.868°, and the inner wheel requires a steering angle of δ_i=77.397°. After improvements, for a 5.5-meter turning radius, the outer wheel requires a steering angle of δ_0=15.960°, and the inner wheel requires a steering angle of δ_i=71.321°. It can be concluded that this design can optimize the performance of the knuckle steering system.

Effects of strut cover and lower vertical fin in podded propulsion units on ship maneuverability

To investigate the effects of a strut cover and lower vertical fin in podded propulsion units (POD units) on the maneuverability of a POD-driven ship, free-running model tests (turning test, spiral/revers spiral test, and zig-zag maneuver test) were conducted for three different profiles of the POD units: only a vertical strut without the strut cover or fin (F0), smaller strut cover and smaller fin (FS), and larger strut cover and larger fin (FL). The profile area increases in the order of F0, FS, and FL. The tests were conducted using two propeller positions: one with a propeller equipped in front of the POD units (PULL position) and another with the propeller equipped behind the POD units (PUSH position). The steady turning performance at a steering angle of 35° in the PULL position deteriorated in the order of F0, FS, and FL. In contrast, in the case of the PUSH position, the turning performance improved in the order of F0, FS, and FL. Thus, the PULL and PUSH positions demonstrated different tendencies. The non-dimensional steady yaw rate exceeded 1.0 in all cases, which indicates that the present ship has an excellent turning performance. Furthermore, captive model tests (the POD steering force test in straight towing, oblique towing test, and circular motion test) were conducted to determine the effects of the strut cover and lower vertical fin on the lateral force and yaw moment acting on the ship model. It was found that the large strut cover and fin increase the steering force and improves the course stability of the ship in both the PULL and PUSH positions.

The first distributed-mass high-performance programmable optoelectromechanical steerable motion-wave sensors focused on sophisticated biomedical applications

This paper introduces the first high-performance distributed-mass acoustic sensor made of cascaded differential phase shift suspended slot waveguide sections in a Mach–Zehnder interferometer optical transducer circuit. The heavyweight seismic mass used in traditional optoelectromechanical sensors is replaced by an fg lightweight coupling arm yielding an extra compact fast responding structure enabling utilizing over 64\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$64$$\\end{document} cascaded sections and resulting in enhancing the performance by hundreds of times. The transducer operation relies on converting the acoustic vibration into phase modulation of the light for a splendid performance. The novel sensor architecture challenges achieving optical sensitivities higher than 33×103%/g\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$33\ imes {10}^{3} \\%/\\mathrm{g}$$\\end{document} (33 times supersensitive), operating at ultrasonic acoustic speeds higher than 27 MHz, and recognizing resolutions in the 1 ng order. The programmable sensor is voltage-controlled supporting the operation in multimodes. Four operation modes are elucidated including the natural aspiration force, turbo electrostatic force open-loop voltage control, zero-force closed-loop voltage control, and dynamic turbo-force closed-loop voltage control. Wide dynamic ranges for controlling the optical sensitivity and maximum measurable acceleration up to 115.5 dB are reported. Steering capabilities of the acoustic beam in the azimuth plane are demonstrated utilizing two-spoke and three-spoke directional architectures supporting 116.64∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$116.64^\\circ$$\\end{document} and 360∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$360^\\circ$$\\end{document} of respective steering angles. Potential acoustic biosignal-based applications in the medical field are outlined.

Adaptive heading control strategy for unmanned ground vehicle with variable wheelbase based on robust-active disturbance rejection control

In order to fully exploit the variable wheelbase characteristics of the unmanned ground vehicle (UGV) with variable configuration, this paper proposes an adaptive heading tracking control strategy based on wheelbase changes. This strategy involves adjusting the wheelbase according to different working conditions to optimize various driving performance aspects. Firstly, the impact of changing wheelbase on the response characteristics of sideslip angle and heading angle relative to the front-wheel steering angle is analyzed by using a lateral vehicle dynamic model. The configurations where the 2nd axle moves forward by 0.5 m, remains unchanged, and moves backward by 0.5 m are defined as the ‘stable configuration’, ‘balanced configuration’, and ‘maneuverable configuration’, respectively. Considering time lag effects of hydraulic systems and external random noise interference, a robust-active disturbance rejection control (r-ADRC) method is developed by incorporating a robust term into active disturbance rejection control (ADRC) in order to achieve desired front-wheel steering angle. Additionally, a torque distribution method based on the tire load rate and the real-time vertical load of each wheel is applied to ensure uniform tire wear and enhance longitudinal driving stability. Finally, simulations under various typical working conditions as well as scaled prototype experiments are conducted, and both the theory behind the changing wheelbases and the effectiveness of proposed control strategy are verified. According to different vehicle configurations and mission requirements, the maneuverability and stability of the ground unmanned vehicle are ensured respectively.

Design and realization of directivity adjustable ring transducer

In this paper, a directional segmented ring transmitting transducer, which can radiate sound waves in any horizontal region, has been developed. First, we introduce the structure of the segmented ring transducer and the characteristics of its radiation sound field, investigate the transmitting beam pattern control method based on the modal synthesis, and propose orthogonal beam pattern functions to adjust steering angles. Then, the three-dimensional finite element model of the segmented ring transducer is established, and the amplitude and phase of sound pressure excited by the first three modes, respectively, are calculated as a function of the frequency. We can combine each mode to obtain the desired beam patterns, and simulate the transmitting beam patterns steering to different directions. Finally, we manufacture the segmented ring transducer and measure its transmitting directivity in an anechoic water tank, and the first three modes are also calibrated according to the measured sound pressure. The experimental results show that the beam pattern synthesized by the first two modes has a 3 dB down beam width of about 156◦ at 15 kHz after calibration, and the maximum source level is approximately 24 dB higher than the minimum. The −3 dB beam width synthesized by the first three modes is about 84◦ at 17 kHz after calibration. In addition, we also carry out the experimental test on the proposed beam control method, and the driving-voltage weighting vectors are designed to obtain good transmitting beam patterns steering to different angles.

Yawing stability and manipulative approach design for maglev car based on active disturbance rejection control

AbstractIn the present work, to realize the stable static suspension of a new type of electrodynamic wheel (EDW) magnetic levitation (maglev) car without track constraints on the conductor plate. Design and analysis of the active disturbance rejection control and explicit complementary filter (ADRC‐ECF) have been presented to solve the maglev car's yaw angle disturbance rejection under low lateral damping characteristics. Simple and efficient ECF helps to filter the high and low frequency noise generated by EDWs when rotating at high speed, to obtain accurate data in real‐time. Design and build the hardware control system for maglev car, and conduct experimental comparisons with PID controller to verify the effectiveness of suppressing yaw angle disturbances. Based on simulation and experimental results, it is shown that both PID and ADRC‐ECF can improve the stable yaw angle convergence of maglev car under external disturbances. However, ADRC performs better in resisting disturbances than PID and can achieve more accurate fixed angle steering. This paper is the first attempt to control maglev car on a trackless conductor plate for precise steering and anti‐disturbance, which is anticipated to have some reference significance in this field.

Influence of asymmetrical factors on aircraft ground steering stability

An aircraft taxiing on the ground is affected by several nonlinear forces so that the directional instability may occur during the steering process, and the asymmetric factors could exacerbate this phenomenon. A nonlinear asymmetrical aircraft ground taxiing dynamic model is established in MATLAB/Simulink in this study. Then the numerical continuation method based on the bifurcation theory is used to study the influence of the asymmetrical aircraft structure on the taxiing directional stability by taking the distance between the eccentric mass and the aircraft symmetry plane as the bifurcation parameter. In addition, a dual-parameter bifurcation is conducted to study the influence of the nose-wheel steering angle and the asymmetrical mass eccentric distance on the directional stability. Moreover, the effect of the asymmetrical thrust on the taxiing steering bifurcation characteristics is investigated, and the instability mechanism is revealed by analyzing the aircraft taxiing motion states under five working conditions. Then the dual-parameter bifurcation curves are obtained by introducing the nose wheel steering angle as the additional bifurcation parameter. The Bogdanov-Takens (BT) bifurcation and the Generalized Hopf (GH) bifurcation in the nonlinear ground turning dynamic system are also discussed. The results show that the asymmetrical factors can significantly affect the aircraft ground taxiing directional stability.

The Development of a Steering Angle Estimation Model for Evaluation of Simulated Ship Handling Training for Remote Operators of Autonomous Ships

Through technological development, ships are being automated, reducing the number of human operators. Accordingly, the responsibility of humans becomes more significant, making a single operator’s proficiency count. Simulated ship-handling training evaluates trainees’ proficiency using specific criteria to verify proficiency. However, the present criteria are confined to training scenarios, and it is hard to determine whether trainees finally achieved expert-like ability. This research conducted probabilistic estimation on experts’ average steering angles. The paper contains the corresponding explanations for each step of the research methods, from the data preprocessing step to the probabilistic steering angle estimation. The research findings include the experts’ trendline of average steering angles and the sample trainee’s evaluation results.

Çift taraflı park edilmiş dar sokaklarda paralel park için geometrik yol planlaması

The aim of the paper is to propose collision-free path planning algorithm for autonomous parallel parking based on Ackermann steering geometry. A geometrical path planning algorithm has been employed for generating a path that is based on two straight lines and two identical circles. The algorithm is taking into account that the left side of the street is taken as another parking slot occupied by full of cars. The ego’s kinematics model appropriate for the low-velocity parking scenario and the maximum allowable steering angle for the narrow streets is used in the path planning stage by considering mechanical and environmental limits. According to the steering angle, required length of the parking space is obtained. The algorithm can adapt itself according to the lateral position of the ego in case it is parallel to other parked cars. The steering angle to be used and the required parking space length according to the lateral position of the vehicle in the environmental model are given with graphics.

Reconfigurable and multiple beam steerable non-orthogonal-multiple-access system for optical wireless communication

The ability to reconfigure and adapt to different application scenarios plays an important role in future wireless communication systems. Here, a beam dividable and steerable optical wireless communication (OWC) system adopting a spatial light modulator (SLM) is presented. The reconfigurable multiple beam splitter as well as the adjustable splitting ratio are demonstrated. Experimental results show the proposed system can nearly evenly partition the input beam into up to five spots and can have the adjustable splitting ratio for the two-spot case. Combining non-orthogonal multiple access (NOMA) and wavelength division multiplexing (WDM), the proof-of-concept experimental demonstration shows the proposed system can provide 320.08 Gbit/s and 179.68 Gbit/s for the single-user scenario without beam steering and with steering of about 4°, respectively. Moreover, the data rates pairs of (92.20 Gbit/s, 119.17 Gbit/s) and (51.50 Gbit/s, 124.78 Gbit/s) can be achieved for the two-user scenario at different beam steering angles, respectively. The flexibility of data rate allocation for multiple users is also discussed. The OWC system under evaluation can satisfy the pre-forward error correction bit-error rate limit (pre-FEC BER = 3.8 × 10−3).

Development and Experiment of an Innovative Row-Controlled Device for Residual Film Collector to Drive Autonomously along the Ridge.

The field harvesting process of harvesting machinery is often affected by high workload and environmental factors that can impede/delay manual rowing, thereby leading to lower efficiency and quality in the residual film collector. To address this challenge, an automatic rowing control system using the 4mz-220d self-propelled residual film collector as the experimental carrier was proposed in this study. Cotton stalks in the ridges were chosen as the research object, and a comprehensive application of key technologies, machinery, and electronic control was used, thereby incorporating a pure tracking model as the path-tracking control method. To achieve the automatic rowing function during the field traveling process, the fuzzy control principle was implemented to adjust the forward distance within the pure tracking model dynamically, and the expected steering angle of the steering wheel was determined based on the kinematic model of the recovery machine. The MATLAB/Simulink software was utilized to simulate and analyze the proposed model, thus achieving significant improvements in the automation level of the residual film collector. The field harvesting tests showed that the average deviation of the manual rowing was 0.144 m, while the average deviation of the automatic rowing was 0.066 m. Moreover, the average lateral deviation of the automatic rowing was reduced by 0.078 m with a probability of deviation within 0.1 m of 95.71%. The research study demonstrated that the designed automatic rowing system exhibited high stability and robustness, thereby meeting the requirements of the autonomous rowing operations of residual film collectors. The results of this study can serve as a reference for future research on autonomous navigation technology in agriculture.

Boosting the Response of Object Detection and Steering Angle Prediction for Self-Driving Control

Our previous work introduced the LW-YOLOv4-tiny and the LW-ResNet18 models by replacing traditional convolution with the Ghost Conv to achieve rapid object detection and steering angle prediction, respectively. However, the entire object detection and steering angle prediction process has encountered a speed limit problem. Therefore, this study aims to significantly speed up the object detection and the steering angle prediction simultaneously. This paper proposes the GhostBottleneck approach to speed the frame rate of feature extraction and add the SElayer method to maintain the existing precision of object detection, which constructs an enhanced object detection model abbreviated as LWGSE-YOLOv4-tiny. In addition, this paper also conducted depthwise separable convolution to simplify the Ghost Conv as depthwise separable and ghost convolution, which constructs an improved steering angle prediction model abbreviated as LWDSG-ResNet18 that can considerably speed up the prediction and slightly increase image recognition accuracy. Compared with our previous work, the proposed approach shows that the GhostBottleneck module can significantly boost the frame rate of feature extraction by 9.98%, and SElayer can upgrade the precision of object detection slightly by 0.41%. Moreover, depthwise separable and ghost convolution can considerably boost prediction speed by 20.55% and increase image recognition accuracy by 2.05%.

Real-Time Path Planning for Obstacle Avoidance in Intelligent Driving Sightseeing Cars Using Spatial Perception

The increasing prevalence of intelligent driving sightseeing vehicles in the tourism industry underscores the critical importance of real-time planning for effective local obstacle avoidance paths when these vehicles encounter obstacles during operation. To fulfill this requirement, it is imperative to establish real-time dynamic perception as the foundational element. Thus, this paper introduces a novel local path planning algorithm founded on the principles of spatial perception. In the diverse array of road environments characterized by varying spatial features, sightseeing vehicles can effectively achieve safe and comfortable obstacle avoidance maneuvers. The proposed approach employs a high-precision positioning module and a real-time dynamic perception module to acquire real-time spatial information pertaining to the sightseeing vehicle and the road environment. It comprehensively integrates spatiotemporal safety constraints and obstacle avoidance curvature constraints to derive control points for the obstacle avoidance path. Specific control points undergo optimization and adjustment, ultimately resulting in the generation of the obstacle avoidance spatiotemporal path through discrete interpolation using B-spline curves. These locally tailored paths are subsequently compared with local obstacle avoidance paths generated using Bezier curves. The empirical validation of the proposed local obstacle avoidance path algorithm is conducted through a combination of simulation analysis and real vehicle verification. The research outcomes affirm that the algorithm can indeed produce smoother local obstacle avoidance paths, resulting in reduced front-wheel steering angles and yaw angle variations. This enhancement substantially contributes to the overall stability of sightseeing vehicles during obstacle avoidance maneuvers.

Ways to increase the stability of the movement of cars at small and large angles of rotation of the controlled wheels

The controllability and stability of the car are the most important operational properties and components of the active safety of its movement. Currently, the issues of creating active security systems are actively engaged all over the world. The purpose of the work is to analyze ways to increase the stability of the movement of a two—axle wheeled vehicle at small and large angles of rotation of the controlled wheels. A new method is proposed for analyzing ways to increase the stability of a two-axle wheeled vehicle, characterized in that it allows, based on the application of the second Lyapunov method, to identify methods to increase the stability of movement at small and large angles of rotation of controlled wheels. The analysis of the stability of the movement of two-axle wheeled vehicles at large rotation angles of controlled wheels with various traction and steering drive schemes is carried out. It is proved that for a two-axle wheeled vehicle with all driving and steerable wheels at small angles, the corrective steering angle on the rear axle should be directed towards reducing the angle of rotation of the front wheels of the rear axle modulo and, in addition, the rotation of the rear steerable wheels should begin later than the rotation of the front, i.e. with a delay. Keywords: сontrollability and stability of wheeled vehicles; large rotation angles of the driven wheels; redistribution of torques

Solid-state Lidar with wide steering angle using counter-propagating beams

In a solid-state photonics-based Lidar, all essential components can be integrated into a silicon chip. It is simple and effective to use a tunable laser source to implement Lidar’s beam steering. However, how to effectively increase the steering angle in a small wavelength tuning range is usually a key challenge due to the limited material and waveguide dispersion. In Silicon-on-insulator waveguide, we design a novel solid-state Lidar using two trans-electrical (TE) polarized beams counter-propagating towards each other. Two corresponding output beams from just a single grating coupler (GC) can be seamlessly combined to double the beam steering angle. Furthermore, a low-priced solid-state Lidar is designed for TE polarized beams counter-propagating towards each other by using wavelength division multiplexed laser array.

An algorithm for solving the equilibrium points of high-dimensional nonlinear vehicle dynamic system based on a combination of genetic algorithm, sequential quadratic programming method, and continuation method

The paper proposes an algorithm that combines Genetic Algorithm, Sequential Quadratic Programming, and Continuation Method to solve the equilibrium points of a multi-degree-of-freedom vehicle nonlinear system. The algorithm’s effectiveness is demonstrated by applying it to search for equilibrium points of a 5-degree-of-freedom (5DOF) nonlinear vehicle model, which considers both longitudinal and lateral motion. The dynamic equilibrium points of front-wheel-drive, rear-wheel-drive, and all-wheel-drive vehicles with different front-wheel steering angle inputs are calculated. Taking the front-wheel-drive system as an example, the system equilibrium points are further analyzed using phase space analysis and eigenvalue analysis for verification. In addition, the impact of the driving effect on the equilibrium points bifurcation is investigated. The results show that compared with the Genetic Algorithm alone and the combination method of Genetic Algorithm and Sequential Quadratic Programming, the proposed algorithm can effectively and accurately solve the equilibrium points of the 5DOF vehicle model. The study also reveals that the driving effect significantly influences the vehicle equilibrium point bifurcation.

End-to-End Steering Angle Prediction for Autonomous Car Using Vision Transformer

The development of autonomous cars is currently increasing along with the need for safe and comfortable autonomous cars. The development of autonomous cars cannot be separated from the use of deep learning to determine the steering angle of an autonomous car according to the road conditions it faces. In the research, a Vision Transformer (ViT) model is proposed to determine the steering angle based on images taken using a front-facing camera on an autonomous car. The dataset used to train ViT is a public dataset. The dataset is taken from streets around Rancho Palos Verdes and San Pedro, California. The number of images is 45,560, which are labeled with the steering angle value for each image. The proposed model can predict steering angle well. Then, the steering angle prediction results are compared using the same dataset with existing models. The experimental results show that the proposed model has better accuracy regarding the resulting MSE value of 2,991 compared to the CNN-based model of 5,358 and the CNN-LSTM combination model of 4,065. From the results of this experiment, the ViT model can replace the existing model, namely the CNN model and the combination model between CNN and LSTM, in predicting the steering angle of an autonomous car.

Design of a Wideband, High Steering Angle and Low Side-Lobes Levels Matrix Antenna

This paper presents the use of pixel-type radiating elements in the context of broadband beam steering. The elements are composed of a resonant cavity topped by a frequency selective surface, fed via a patch antenna and filled with dielectric substrates. This pixel antenna has a wide -10 dB matching band from 1.22 to 1.61 GHz, which corresponds to a 27% fractional bandwidth. It has an angular aperture greater than 124° and a realized gain between 3.3 and 3.8 dBi over the whole matching band. An array composed of 5 elements has been simulated and allows a steering on a range of ±60° in the E plane while keeping the gain variation below 3 dB. A prototype has been manufactured and presents a steering capacity between -56 and 53° on the whole band with side-lobes levels lower than -8.1 dB whatever the angle.

Multimodal fusion for sensorimotor control in steering angle prediction

Efficient reasoning about the spatial and temporal structure of the environment is crucial for perception in autonomous driving, particularly in an end-to-end approach. Although different sensor modalities are employed to capture the complex nature of the environment, they each have their limitations. For example, frame-based RGB cameras are susceptible to variations in illumination conditions. However, these limitations at the sensor level can be addressed by complementing them with sensor fusion techniques, enabling the learning of efficient feature representations for end-to-end autonomous perception. In this study, we address the end-to-end perception problem by fusing a frame-based RGB camera with an event camera to improve the learned representation for predicting lateral control. To achieve this, we propose a convolutional encoder–decoder architecture called DRFuser. DRFuser encodes the features from both sensor modalities and leverages self-attention to fuse the frame-based RGB and event camera features in the encoder part. The decoder component unrolls the learned features to predict lateral control, specifically in the form of a steering angle. We extensively evaluate the proposed method on three datasets: our collected Dataset, Davis Driving dataset, and the EventScape dataset for simulation. The results demonstrate the generalization capability of our method on both real-world and simulated datasets. We observe qualitative and quantitative improvements in the performance of the proposed method for predicting lateral control by incorporating the event camera in fusion with the frame-based RGB camera. Notably, our method outperforms state-of-the-art techniques on the Davis Driving Dataset, achieving a 5.6% improvement in the root mean square error (RMSE) score.

Wireless Millimeter-Size Soft Climbing Robots with Omnidirectional Steerability on Tissue Surfaces.

Wirelessly actuated miniature soft robots actuated by magnetic fields that can overcome gravity by climbing soft and wet tissues are promising for accessing challenging enclosed and confined spaces with minimal invasion for targeted medical operation. However, existing designs lack the directional steerability to traverse complex terrains and perform agile medical operations. Here we propose a rod-shaped millimeter-size climbing robot that can be omnidirectionally steered with a steering angle up to 360 degrees during climbing beyond existing soft miniature robots. The design innovation includes the rod-shaped robot body, its special magnetization profile, and the spherical robot footpads, allowing directional bending of the body under external magnetic fields and out-of-plane motion of the body for delivery of medical patches. With further integrated bio-adhesives and microstructures on the footpads, we experimentally demonstrated inverted climbing of the robot on porcine gastrointestinal (GI) tract tissues and deployment of a medical patch for targeted drug delivery.