Analysis of the Energy Loss on Quadruped Robot Having a Flexible Trunk Joint

2017 ◽  
Vol 29 (3) ◽  
pp. 536-545
Author(s):  
Masahiro Ikeda ◽  
◽  
Ikuo Mizuuchi
Keyword(s):  
Energy Loss ◽  
Energy Flow ◽  
Control Method ◽  
Quadruped Robot ◽  
Rough Terrain ◽  
Legged Robot ◽  
Walking Robot ◽  
Passive Joint ◽  
Quadruped Robots ◽  
The Relationship

[abstFig src='/00290003/09.jpg' width='300' text='Energy flow in legged robot' ] As a method of robot movement, legs have the advantage of traversability on rough terrain. However, the motion of a legged robot is accompanied by energy loss. The main causes for this loss could be negative work and contact between the legs and ground. On the other hand, animals with legs are considered to reduce energy loss by using the elasticity of their body. In this study, we analyze the influence of walking, using an elastic passive joint mounted on the trunk of a quadruped robot, on the energy loss. Additionally, we study the energy flow between legs and elastic components. In this study, we clarify a control method for quadruped robots in order to reduce the energy loss of walking. The results of simulating a quadruped walking robot, which has passive joints with elastic components on the trunk, are analyzed and the relationship between each kind of energy loss and the trunk joint’s elasticity is clarified.

Kinematical Model and Topology Patterns of a New 6-Parallel-Legged Walking Robot

2012 ◽  
Author(s):  
Pan Yang ◽  
Feng Gao
Keyword(s):  
Working Conditions ◽  
Force Control ◽  
Control Method ◽  
Design Method ◽  
Legged Robot ◽  
Walking Robot ◽  
Actuation Force ◽  
And Topology ◽  
Kinematical Model ◽  
The Relationship

In this paper, a new kind of 6-legged robot is presented. It was designed for drilling holes on the aircraft surface. Each leg of the robot is a 3-DOF parallel mechanism and the actuation can be controlled both by position and force. The mechanism design method of the robot is discussed. The relationship between control method and motion topology under different working conditions is studied. The kinematical model is built, based on which the motion plan are made. The control method is position-force control, so the calculation of actuation force is done. Finally, the simulation result is showed: the robot can drill on the fuselage surface successfully and the position-force control method can improve its performance a lot.

scholarly journals Self-Stabilising Quadrupedal Running by Mechanical Design

2009 ◽  
Vol 6 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Panagiotis Chatzakos ◽  
Evangelos Papadopoulos
Keyword(s):  
Mechanical System ◽  
Mechanical Design ◽  
Quadruped Robot ◽  
The Self ◽  
Rough Terrain ◽  
Stable Regime ◽  
Quadruped Robots ◽  
The Stability ◽  
Running Robots ◽  
Body Inertia

Dynamic stability allows running animals to maintain preferred speed during locomotion over rough terrain. It appears that rapid disturbance rejection is an emergent property of the mechanical system. In running robots, simple motor control seems to be effective in the negotiation of rough terrain when used in concert with a mechanical system that stabilises passively. Spring-like legs are a means for providing self-stabilising characteristics against external perturbations. In this paper, we show that a quadruped robot could be able to perform self-stable running behaviour in significantly broader ranges of forward speed and pitch rate with a suitable mechanical design, which is not limited to choosing legs spring stiffness only. The results presented here are derived by studying the stability of the passive dynamics of a quadruped robot running in the sagittal plane in a dimensionless context and might explain the success of simple, open loop running controllers on existing experimental quadruped robots. These can be summarised in (a) the self-stabilised behaviour of a quadruped robot for a particular gait is greatly related to the magnitude of its dimensionless body inertia, (b) the values of hip separation, normalised to rest leg length, and leg relative stiffness of a quadruped robot affect the stability of its motion and should be in inverse proportion to its dimensionless body inertia, and (c) the self-stable regime of quadruped running robots is enlarged at relatively high forward speeds. We anticipate the proposed guidelines to assist in the design of new, and modifications of existing, quadruped robots. As an example, specific design changes for the Scout II quadruped robot that might improve its performance are proposed.

Design and Control Method of a Planar Omnidirectional Crawler Mechanism

2021 ◽  
pp. 1-29
Author(s):  
Eri Takane ◽  
Kenjiro Tadakuma ◽  
Masahiro Watanabe ◽  
Masashi Konyo ◽  
Satoshi Tadokoro
Keyword(s):  
Control Method ◽  
Soft Soil ◽  
Rough Terrain ◽  
Distribution Centers ◽  
Uneven Terrain ◽  
Large Pressure ◽  
Large Contact Area ◽  
Heavy Loads ◽  
And Control ◽  
The Relationship

Abstract Omnidirectional mobility is a popular method of moving in narrow spaces. In particular, the planar omnidirectional crawler previously developed by the authors can traverse unstable and uneven terrain with a large contact area. A novel point is that the proposed system is unique in its ability to carry heavy loads in all directions without getting stuck because of the large pressure-receiving area between the crawler and ground. This work will facilitate omnidirectional motion, which has important implications for the use of robots in spaces such as not only factories, distribution centers, and warehouses but also soft soil in disaster sites. The objective of the present study was to establish a design and control method for an omnidirectional crawler mechanism that can conduct holonomic and two-axis cross driving. Only two motors are set on the crawler base for translation in the X- and Y-directions, and two large crawler units are arranged for turning. We design a small crawler that has higher traversing ability with a derailment prevention mechanism and tapered track. Further, the relationship between the motor rotational speed as input and crawler velocity as output was verified for control. In addition, it was demonstrated experimentally that the proposed crawler could travel across various types of rough terrain in a target direction.

The Mathematical Modeling and Dynamic Trot Gait Simulation on the Single Leg Hydraulic Drive System of the Quadruped Robot

2017 ◽  
Vol 865 ◽  
pp. 417-422
Author(s):  
Xiang Dong Kong ◽  
Kai Xian Ba ◽  
Bin Yu ◽  
Chun He Li ◽  
Qi Xin Zhu ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Position Control ◽  
Control Method ◽  
Simulation Analysis ◽  
Hydraulic Drive ◽  
Quadruped Robot ◽  
Drive System ◽  
Nonlinear Mathematical Model ◽  
Trot Gait ◽  
The Relationship

In this paper, the single leg hydraulic drive system of the quadruped robot is taken as the research object. Then the nonlinear mathematical model of the hydraulic system is built. According to the real mechanical structure parameters of the single leg, the relationship between position control characteristics of the system and variation of single leg trajectory is investigated. Besides, the tracing accuracy of single leg foot displacement in one trot gait condition is analyzed through combination of kinematics solution and simulation analysis. In conclusion, the research indicates that the nonlinear mathematical model can be used to analyze the position control performance of the single leg hydraulic drive system. This research provides a basic foundation for further research of control method.

Light Weight Quadruped with Nine Actuators

2007 ◽  
Vol 19 (2) ◽  
pp. 160-165 ◽  
Author(s):  
Kan Yoneda ◽  
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Quadruped Robot ◽  
Light Weight ◽  
Quadruped Locomotion ◽  
Quadruped Robots ◽  
Reduce Energy Consumption ◽  
Relationship Of ◽  
The Relationship

Quadruped robots, which tend to be heavy can be made lighter by carefully considering the number of actuators and required power. This paper discusses the relationship of the moving functions of quadruped locomotion and the required number of actuators. Using fewer actuators than conventionally need not prevent the quadruped robot from satisfactory locomotion. At the same time, energy saving brings a lighter design, because required actuators and batteries are smaller. This paper discusses several techniques to reduce energy consumption. Combining these discussions, examples of 3-, 5-, and 9-actuator quadrupeds are designed, and experimentally performed good locomotion.

A new six-parallel-legged walking robot for drilling holes on the fuselage

2013 ◽  
Vol 228 (4) ◽  
pp. 753-764 ◽  
Author(s):  
Yang Pan ◽  
Feng Gao
Keyword(s):  
Working Conditions ◽  
Parallel Mechanism ◽  
Position Control ◽  
Control Method ◽  
Control Mode ◽  
Legged Robot ◽  
Walking Robot ◽  
Kinematical Model ◽  
Prismatic Joints ◽  
Control Curves

In this paper, a new kind of six-parallel-legged robot is presented. It is designed for drilling holes on the aircraft surface. Each leg of the robot is a 3-DOF parallel mechanism with three chains: 1UP and 2UPS. The three prismatic joints are active joints and can be controlled either by position or by force. First, the task process and the gait plan are discussed and then, according to the requirement, the control method is introduced. After that, the mechanism topology patterns under different working conditions are studied and the control mode of each motor is determined. Then the kinematical model is built up, based on which the position control curves can be obtained. The simulation result shows that the robot can walk pretty well on the fuselage surface and that the actuation forces are quite smooth. Furthermore, the first prototype has been manufactured and some experiments such as walking and manipulation have been done.

Dynamic Modeling and Locomotion Control for Quadruped Robots Based on Center of Inertia on SE(3)

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Xilun Ding ◽  
Hao Chen
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Dynamic Control ◽  
Quadruped Robot ◽  
The Body ◽  
State Variables ◽  
Complex Environments ◽  
Simulation Experiments ◽  
Quadruped Robots ◽  
Virtual Body

Quadruped robots have good mobility and agility in complex environments, but dynamic control of locomotion for quadruped robots has long been a big challenge for researchers. In this paper, we build the center of inertia (COI) dynamic model of a general quadruped robot and give the exponential coordinates of COI on the special Euclidean space SE(3). The COI model takes the whole quadruped robot as one body, so that the only concern is the movement of the COI rather than the body or legs when the robot walks. As a result, the COI model has fewer dimensions of state variables than the full dynamic model, which helps to reduce the computational load. A control method for quadruped robots is presented based on the dynamic model which is constituted of force loop and position loop. This method controls the movement of the COI directly, so it facilitates to guarantee the robot's stability. The virtual body of the quadruped robot is defined to describe the configuration of the quadruped robot. The proportional-derivative (PD) control method on SE(3) is applied to control the movement of the virtual body, which makes the movement more in line with the group theoretic viewpoint. Finally, some simulation experiments have been conducted to verify the validity of our method.

Minimalistic Control for Reaching Absolute State of a One-Legged Dynamic Robot on Uncertain Terrain

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Adar Gaathon ◽  
Amir Degani
Keyword(s):  
Path Planning ◽  
Control Method ◽  
Legged Robots ◽  
Basic Block ◽  
Rough Terrain ◽  
Control Parameters ◽  
Legged Robot ◽  
Initial State ◽  
Control Laws ◽  
State Information

Abstract Footstep and path planning for dynamic legged robots is complex, and even if such a plan exists, execution is even harder. We propose a new method for a planar model of a dynamic legged robot that brings the trajectory to an absolute desired destination even on unknown rough terrain with minimal sensing. This can later aid a global planner to reach “way-points” with low destination errors. The basic block of the technique incorporates two consecutive jumps, each triggers a minimalistic control method to govern a sole controller—the leg angle during flight. Only two detection sensors and initial state information are required during implementation. Prior to execution, an optimization process is initiated to obtain the temporal control laws for both jumps. This work presents the process of obtaining the control parameters and studies the performance and limitations of the scheme.

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