Design of a Labriform-Steering Underwater Robot Using a Multiphysics Simulation Environment

Bio-inspired solutions devised for Autonomous Underwater Robots are currently investigated by researchers as a source of propulsive improvement. To address this ambitious objective, the authors have designed a carangiform swimming robot, which represents a compromise in terms of efficiency and maximum velocity. The requirements of stabilizing a course and performing turns were not met in their previous works. Therefore, the aim of this paper is to improve the vehicle maneuvering capabilities by means of a novel transmission system capable of transforming the constant angular velocity of a single rotary actuator into the pitching–yawing rotation of fish pectoral fins. Here, the biomimetic thrusters exploit the drag-based momentum transfer mechanism of labriform swimmers to generate the necessary steering torque. Aside from inertia and encumbrance reduction, the main improvement of this solution is the inherent synchronization of the system granted by the mechanism’s kinematics. The system was sized by using the experimental results collected by biologists and then integrated in a multiphysics simulation environment to predict the resulting maneuvering performance.

Hardware in the loop simulation technology evaluation method for power steering systems

In the paper, the method of measuring and assessing of steering systems with the help of test benches with HILS technology implementation is justified in part of the adaptive algorithms of the regulation of the assistant steering torque. In the article, overall principal of creating virtual – physical system using as a physical part the rack and pinion steering system with electromechanical assistant is described. Interaction of the physical and virtual parts and fields of usage are described. Development, calibration and tweaking of the newly designed ECU and adaptive algorithms suppose a lot of testing. Time consumption and difficultness can be reduced only by the way of carrying out bench tests with usage of HILS technology.

A Review Paper on Electric Assisted Steering System for Automobiles

Electric Assisted Steering system is an Electric System, which reduces the amount of steering effort by directly applying the output from the electric motor to the steering system.In this system the mechanical link between the steering wheel and road wheels of an automobile are replaced by a control system consisting of sensors, actuators and controllers seem to offer great advantages such as enhanced system performance, simplified construction, design flexibility etc.It offers greater vehicle safety by adapting variable steering ratios to human needs, filtering drive train influences and even adjusting active steering torque in critical situations. In addition, it can make cars even lighter and more fuel efficient when compared to those using hydraulic steering systems. The central electronic elements of today’s steering systems are modern microcontrollers

Novel Two-stage Nonlinear Interconnected Unknown Input Observer Design: Hardware & Experimental Vehicle Validation

This paper concerns both vehicle lateral and longitudinal nonlinear dynamics estimation. Consequently, the interlinked vehicle models dependency and the hurdle coupling features will be overcome here thanks to the NONLINEAR INTERCONNECTED UNKNOWN INPUTS OBSERVER (NI-UIO) framework. This interconnection scheme extends the estimation of the lateral motion to the longitudinal one with the unknown accelerator, brake pedal and driver steering torque inputs, as well as tire-ground pneumatic efforts to reduce conservatism and observability problems. The aspects of immeasurable real-time variation in the forward speed and tire slip velocities in front and rear wheels are taken particularly into account. Consequently, TAKAGI-SUGENO (TS) fuzzy form is undertaken to deal with these nonlinearities in the observer synthesis. The INPUT TO STATE STABILITY (ISS) of the estimation errors is exploited using Lyapunov stability arguments to allow more relaxation and additional robustness guarantee regarding the disturbance term of immeasurable nonlinearities. Therein, sufficient conditions of the ISS property are formulated as an optimization problem in terms of linear matrix inequalities (LMIs). Finally, hardware and experimental validation with robustness test are performed with the well-known SHERPA dynamic interactive driving simulator as well as TWINGO vehicle prototype to highlight performances and applicability of the outlined observer.

Musculoskeletal Driver Model for the Steering Feedback Controller

This paper aims to find a mathematical justification for the non-linear steady state steering haptic response as a function of driver arm posture. Experiments show that different arm postures, that is, same hands location on the steering wheel but at different initial steering angles, result in a change in maximum driver arm stiffness. This implies the need for different steering torque response as a function of steering angle, which is under investigation. A quasi-static musculoskeletal driver model considering elbow and shoulder joints is developed for posture analysis. The torque acting in the shoulder joint is higher than in the elbow. The relationship between the joint torque and joint angle is linear in the shoulder, whereas the non-linearity occurs in the elbow joint. The simulation results qualitatively indicate a similar pattern as compared to the experimental muscle activity results. Due to increasing muscle non-linearity at high steering angles, the arm stiffness decreases and then the hypothesis suggests that the effective steering stiffness is intentionally reduced for a consistent on-center haptic response.