Rush: A simple and autonomous quadruped running robot

Author(s):  
Z G Zhang ◽  
H Kimura

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.

2007 ◽  
Vol 19 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Zu Guang Zhang ◽  
◽  
Hiroshi Kimura ◽  
Yasuhiro Fukuoka ◽  
◽  
...  

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.


2017 ◽  
Vol 29 (3) ◽  
pp. 546-555 ◽  
Author(s):  
Takashi Takuma ◽  
◽  
Yoshiki Murata ◽  
Wataru Kase

[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.


1998 ◽  
Vol 37 (12) ◽  
pp. 219-226 ◽  
Author(s):  
Henri Spanjers ◽  
Peter Vanrolleghem ◽  
Khanh Nguyen ◽  
Henk Vanhooren ◽  
Gilles G. Patry

Many respirometry-based control strategies have been proposed in the literature but few successful practical implementations or even simulation-based evaluations have been reported. The state-of-the-art provides insufficient justification for the development of a how-to-do procedure for such control strategies in full scale. It is, therefore, expected that carefully conducted simulation studies will greatly support the evaluation of proposed strategies and, eventually, the implementation in practice. These studies should be based on a rigorous methodology including simulation model, plant layout, controller and test procedure. This paper describes the development of such a methodology, termed “benchmark”. The benchmark is evaluated on the basis of a respirometry-based control strategy from the literature. Some simulation results are shown and modifications to the strategy imperative to the implementation in the benchmark are discussed. It is concluded that the benchmark provides a convenient means to perform a number of tests with the implemented control strategy. The benchmark should be further developed and tested.


Author(s):  
Guang Xia ◽  
Yan Xia ◽  
Xiwen Tang ◽  
Linfeng Zhao ◽  
Baoqun Sun

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.


2015 ◽  
Vol 713-715 ◽  
pp. 756-759
Author(s):  
Xu Guang Zhang ◽  
Zhen Xie

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.


2013 ◽  
Vol 336-338 ◽  
pp. 734-737
Author(s):  
Hong Yu Zheng ◽  
Ya Ning Han ◽  
Chang Fu Zong

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.


2015 ◽  
Vol 738-739 ◽  
pp. 986-990
Author(s):  
Zhi Gang Wang ◽  
Jia Guang Cheng ◽  
Yan Wang ◽  
Qiang Shen

Organic Rankine Cycle (ORC) is one of the most promising technologies for low-temperature energy conversion. In recent years, it has gotten more attention due to the energy crisis and environmental problems caused by the combustion of fossil fuels. In this paper, a moving boundary model is introduced to describe the transient phenomena of evaporator and condenser, which are the important components of ORC. The simulation results are given to illustrate the efficiency and feasibility of the proposed control strategy.


2013 ◽  
Vol 330 ◽  
pp. 615-618
Author(s):  
Cheng Lin ◽  
Zhi Feng Xu

There is no mechanical connection between two driving motors of two-motor independent driven vehicle. In order to solve target vehicles differential problem, this paper has proposed self-adaptive differential control strategy, and based on that, has proposed anti-slip control strategy through limiting the motor driving torque. Then, the anti-slip differential effect has been tested by simulation. The simulation results have proved that good anti-slip differential effect can be realized by using the anti-slip differential control strategy proposed by this paper.


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