scholarly journals Self-Stabilizing Dynamics for a Quadruped Robot and Extension Toward Running on Rough Terrain

2007 ◽  
Vol 19 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Zu Guang Zhang ◽  
◽  
Hiroshi Kimura ◽  
Yasuhiro Fukuoka ◽  
◽  
...  
Keyword(s):  
Control Strategy ◽  
Pitch Angle ◽  
Energy Input ◽  
Adaptation Strategy ◽  
Quadruped Robot ◽  
Delayed Feedback Control ◽  
Rough Terrain ◽  
Autonomous Adaptation ◽  
Good Energy ◽  
Simulation Results

We designed and analyzed a control strategy that achieves autonomous adaptation and good energy efficiency in running by a quadruped robot. Our control strategy, inspired by previous studies on self-stabilizing dynamics, combines rhythm and torque generators with delayed feedback control (DFC) to achieve stable running and essential energy input. We developed an adaptation strategy to extend this control strategy that adjusts the robot’s leg touchdown angle based on the body’s pitch angle. Used together with our proposed control, it enables robust bounding over a shallow slope. Simulation results confirmed the feasibility of our proposal and its performance.

Rush: A simple and autonomous quadruped running robot

2009 ◽  
Vol 223 (3) ◽  
pp. 323-336 ◽  
Author(s):  
Z G Zhang ◽  
H Kimura
Keyword(s):  
System Design ◽  
Control Strategy ◽  
Energy Efficient ◽  
Sensory Feedback ◽  
Quadruped Robot ◽  
Rough Terrain ◽  
Simulation Studies ◽  
Simulation Results

In this paper, the system design and analysis of a quadruped robot, Rush, are presented. The quadruped robot was fabricated to study autonomous and efficient running on flat and rough terrain. It is a compact, kneed, four-legged machine with only one actuator per compliant leg. A novel control strategy for the quadruped robot has been proposed in consideration of several engineering limitations on sensory feedback. Several simulation studies have already been performed to confirm the validity of the control strategy in the previous reports. In this paper, the results obtained from experiments with Rush are found to agree with the simulation results. The reported work may help improve the understanding of energy-efficient running locomotion and the simple control required to autonomously stabilize it on flat or rough terrain.

scholarly journals Steering Control Method for an Underactuated Unicycle Robot Based on Dynamic Model

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Hongzhe Jin ◽  
Yang Zhang ◽  
Hui Zhang ◽  
Zhangxing Liu ◽  
Yubin Liu ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Control Strategy ◽  
Pitch Angle ◽  
Control Method ◽  
Steering Control ◽  
Dynamics Model ◽  
Gyroscope System ◽  
Simulation Results ◽  
Balance Structure ◽  
Gyroscope Precession

This paper proposes a lateral balancing structure based on precession effect of double-gyroscopes and its associated control strategy of the steering for an underactuated unicycle robot. Double-gyroscopes are symmetrically designed on the top of the unicycle robot and utilized to adjust the lateral balance of system. Such design can inhibit the disturbance of the gyroscope system to the pitch angle and is beneficial to maintain the lateral balance in the case of large roll angle fluctuations. Based on the analysis of the dynamics model, the gyroscope precession effects will be caused by the angular velocity of the bottom wheel and the roll angular velocity, i.e., resulting in a torque in the direction of the yaw. Then, a rapid response control strategy is proposed to use the torque to control the steering. Simulation results demonstrate the rationality of the lateral balance structure and the feasibility of the steering control method.

Design of Vertebrae-Inspired Trunk Mechanism for Robust and Directive Quadruped Locomotion on Rough Terrain Without Requiring Sensing and Actuation

2017 ◽  
Vol 29 (3) ◽  
pp. 546-555 ◽  
Author(s):  
Takashi Takuma ◽  
◽  
Yoshiki Murata ◽  
Wataru Kase
Keyword(s):  
Rigid Body ◽  
Success Rate ◽  
Design Principle ◽  
Quadruped Robot ◽  
Rough Terrain ◽  
Elastic Coefficient ◽  
Sensors And Actuators ◽  
Quadruped Locomotion ◽  
Trunk Posture ◽  
Simulation Results

[abstFig src='/00290003/10.jpg' width='300' text='Quadruped robot equipping a vertebrae-inspired trunk mechanism' ] Quadrupedal animals adaptively change their trunk posture in order to avoid falling down and to facilitate directive locomotion even on rough terrain. This paper focuses on an animal-like trunk mechanism which has passive viscoelastic joints. The effect of the trunk mechanism is observed by changing the elasticity and configuration of joints. Simulation results showed that the locomotion success rate of a robot equipped with the trunk mechanism on rough terrain is higher than the locomotion success rate of a robot equipped with a rigid body. In addition, the distribution of the success rate changes according to the elastic coefficient, number, configuration, and type of joints. These results suggest a design principle for the trunk mechanism of a quadruped robot in order to obtain robust and directive locomotion without requiring sensors and actuators.

Speed regulation control of tractors’ new dual-flow transmission system based on slip rate resistance classification

2021 ◽  
pp. 095440702110105
Author(s):  
Guang Xia ◽  
Yan Xia ◽  
Xiwen Tang ◽  
Linfeng Zhao ◽  
Baoqun Sun
Keyword(s):  
Control Strategy ◽  
Control Algorithm ◽  
Production Efficiency ◽  
Sliding Mode ◽  
Slip Rate ◽  
Speed Control ◽  
Working Environment ◽  
Vehicle Speed ◽  
Speed Change ◽  
Simulation Results

Fluctuations in operation resistance during the operating process lead to reduced efficiency in tractor production. To address this problem, the project team independently developed and designed a new type of hydraulic mechanical continuously variable transmission (HMCVT). Based on introducing the mechanical structure and transmission principle of the HMCVT system, the priority of slip rate control and vehicle speed control is determined by classifying the slip rate. In the process of vehicle speed control, the driving mode of HMCVT system suitable for the current resistance state is determined by classifying the operation resistance. The speed change rule under HMT and HST modes is formulated with the goal of the highest production efficiency, and the displacement ratio adjustment surfaces under HMT and HST modes are determined. A sliding mode control algorithm based on feedforward compensation is proposed to address the problem that the oil pressure fluctuation has influences on the adjustment accuracy of hydraulic pump displacement. The simulation results of Simulink show that this algorithm can not only accurately follow the expected signal changes, but has better tracking stability than traditional PID control algorithm. The HMCVT system and speed control strategy models were built, and simulation results show that the speed control strategy can restrict the slip rate of driving wheels within the allowable range when load or road conditions change. When the tractor speed is lower than the lower limit of the high-efficiency speed range, the speed change law formulated in this paper can improve the tractor speed faster than the traditional rule, and effectively ensure the production efficiency. The research results are of great significance for improving tractor’s adaptability to complex and changeable working environment and promoting agricultural production efficiency.

Research on Flux Damping Control Strategy of DFIG during Grid Voltage Dips

2015 ◽  
Vol 713-715 ◽  
pp. 756-759
Author(s):  
Xu Guang Zhang ◽  
Zhen Xie
Keyword(s):  
Mathematical Model ◽  
Control Strategy ◽  
Grid Voltage ◽  
Damping Control ◽  
Simulink Simulation ◽  
Voltage Dips ◽  
Simulation Results ◽  
Stator Flux ◽  
Natural Component ◽  
Simplified Mathematical Model

A flux damping control strategy was proposed to accelerate the decay of stator flux and restrain stator, rotor current and torque oscillation caused by grid voltage dips. Firstly, this paper analyzes the simplified mathematical model of DFIG during symmetrical voltage dips. Then, the mechanism of flux damping control strategy to restrain stator, rotor current oscillation and increase flux damping was analyzed. The flux damping control strategy can increase the damping of stator side, which accelerates the decay of the stator flux natural component and improve the dynamic LVRT performance of DFIG. The correctness and effectiveness of this method is verified by MATLAB/Simulink simulation results.

Road Feel Design for Vehicle Steer-by-Wire System Based on Joystick

2013 ◽  
Vol 336-338 ◽  
pp. 734-737
Author(s):  
Hong Yu Zheng ◽  
Ya Ning Han ◽  
Chang Fu Zong
Keyword(s):  
Computer Simulation ◽  
Control Strategy ◽  
Vehicle Speed ◽  
Control Module ◽  
Matlab Simulink ◽  
The Road ◽  
Steering Feel ◽  
Steer By Wire ◽  
Simulation Results ◽  
Wire System

In order to solve the problem of road feel feedback of vehicle steer-by-wire (SBW) system based on joystick, a road feel control strategy was established to analyze the road feel theory of traditional steer system, which included return, assist and damp control module. By verifying the computer simulation results with the control strategy from software of CarSim and Matlab/Simulink, it shows that the proposed strategy can effective get road feel in different vehicle speed conditions and could improve the vehicle maneuverability to achieve desired steering feel by different drivers.

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