Central Nervous System (CNS) Based Motion Control

Motion simulators are widely used in several applications ranging from research to commercial training and entertainment in order to replicate real movement situation. These motions can be sensed by human perception organ called Central Nervous System (CNS). This research presents a novel control algorithm called Central Nervous System (CNS) based control that aims to create realistic perception of vehicle simulation. CNS-based motion control was evaluated by computer simulation to classical, adaptive and optimal washout filter. In addition, comparisons of human motion perception are performed on Force Dynamics 301 simulator for longitudinal acceleration driving test of all four washout filters. The subjects were seated in the simulator. Their motion perceptions were measured through vestibulo-ocular reflex (VOR) using EyeSeeCam vHit camera and compared to the estimated VOR from CNS model. The results revealed that CNS-based motion control can crucially reduce the workspace and provide realistic motion sensation.   &nbsp

Kinematics-Based Analytical Solution for Wheel Slip Angle Estimation of a RWD Vehicle with Drift

Accurate real-time information of wheel slip angle is essential for various active stability control systems. A number of techniques have been proposed to enhance quality of GPS based estimation. This paper exhibits a novel cost-effective strategy of individual wheel slip angle estimation for a rear-wheel-drive (RWD) vehicle. At any slip condition, the slip angle can be estimated using only measurement of steering angle, front wheel speeds, yaw rate, longitudinal and lateral accelerations, without requiring GPS data. On the basis of zero longitudinal slip at both front tires, the closed-form solutions for direct computation of wheel slip angles were derived via kinematic analysis of a planar four-wheel vehicle, and then primarily verified by computational simulation with prescribed functions of radius of curvature, vehicle speed, sideslip and steering angle. Neither integration nor tire friction model is required for this estimation methodology. In terms of implementation, a 1:10th scaled RWD vehicle was modified so that the steering angle, the front wheel rolling speeds, the vehicle yaw rate and the linear accelerations can be measured. Preliminary experiment was done on extremely random sideslip maneuvers beneath the global positioning using four recording cameras. By comparing with the vision-based reference, the individual wheel slip angles could be well estimated despite extreme tire slip. Other vehicle state variables - radius of curvature, vehicle sideslip and speed - may also be directly obtained from the kinematic relations. This proposed estimation methodology could then be alternatively applied for the full range slip angle estimation in advanced active safety systems

Tire-Suspension-Steering Hardware-in-the-Loop Simulation

Safety and performance have always been important factors in automotive testing. These factors are highly dependent on the tires and suspensions, which should be simulated and tested throughout the development process. During development, Hardware-In-the-Loop (HIL) simulations may be used so that testings and tunings can be done earlier in the process. In this paper, designs and configurations of a newly developed tire-suspension-steering HIL are shown. An actual wheel assembly with suspension and steering components can be installed for testing with dynamic models of the rest of the car. The slip angle of the tire can be imposed in the test rig while actual tire forces can be measured and used in the dynamic model. Comparisons of HIL simulations and real experiments using the skidpad test and the step steering test are given using Formula SAE race cars. It was found that the HIL simulation results are more accurate compared to non-HIL simulations

A Study and Develop of Fluid Cobot,

ABSTRACT Cobots are a class of passive robotic devices that utilize steering joints to impose nonholonomic constraints on their joints. These steering joints are a subclass of transmission called Continuous Variable Transmission, CVT. Here we purpose to develop a cobot that utilizes a CVT joint based on flow rate divider of pneumatic actuators. We studied characteristics of a valve and a cylinder. We designed and built a multi channel flow divider. Further more, To test our concept we constructed a simple x-y pneumatic cobot

Variable Damping Actuator Using an Electromagnetic Brake for Impedance Modulation in Physical Human–Robot Interaction

Compliance actuation systems are efficient and safe, drawing attention to their development. However, compliance has caused bandwidth loss, instability, and mechanical vibration in robotic systems. Variable physical damping was introduced to address these issues. This paper presents a technique for obtaining variable damping properties using an electromagnetic brake. The relationship mapping of the voltage and the braking torque is studied and applied to the variable damping concept. A new model is proposed to demonstrate the actuation system performance gained by introducing physical damping. The experimental setup comprises an electromagnetic brake and a motor with an integrated controller for speed control and torque feedback. The motor provides the motion, while the electromagnetic brake replicates the damping through a friction mechanism. The variable damping concept was evaluated experimentally using a 1-degree-of-freedom rotational system. Experimental results show that the proposed concept can generate the desired mechanical damping with a high degree of fidelity