Mechanical Design of a Non-Overconstrained Walking Machine

1995 ◽  
Author(s):  
E. Fichter ◽  
B. Fichter
Keyword(s):  
Force Control ◽  
Mechanical Design ◽  
Control Algorithms ◽  
Walking Machine ◽  
Walking Machines ◽  
Darkling Beetles ◽  
Leg Kinematics

Abstract This paper describes the mechanical design of a walking machine that avoids overconstraint. All current walking machines that are also capable of standing on their own are overconstrained and must depend on force control algorithms to control joints. From observations of darkling beetles we have concluded that it is possible for them to perambulate while keeping their bodies constrained but not overconstrained. Our walking machine was built to test hypotheses of how these beetles walk. We discuss the aspects of beetle leg kinematics that are most important for non-overconstrained walking.

Mechanical design of walking machines

2006 ◽  
Vol 365 (1850) ◽  
pp. 171-183 ◽  
Author(s):  
Keisuke Arikawa ◽  
Shigeo Hirose
Keyword(s):  
Energy Efficiency ◽  
Mechanical Design ◽  
Three Dimensional ◽  
Weight Ratio ◽  
Negative Power ◽  
Driving System ◽  
Walking Machine ◽  
Improve Energy Efficiency ◽  
Walking Machines ◽  
Severe Constraint

The performance of existing actuators, such as electric motors, is very limited, be it power–weight ratio or energy efficiency. In this paper, we discuss the method to design a practical walking machine under this severe constraint with focus on two concepts, the gravitationally decoupled actuation (GDA) and the coupled drive. The GDA decouples the driving system against the gravitational field to suppress generation of negative power and improve energy efficiency. On the other hand, the coupled drive couples the driving system to distribute the output power equally among actuators and maximize the utilization of installed actuator power. First, we depict the GDA and coupled drive in detail. Then, we present actual machines, TITAN-III and VIII, quadruped walking machines designed on the basis of the GDA, and NINJA-I and II, quadruped wall walking machines designed on the basis of the coupled drive. Finally, we discuss walking machines that travel on three-dimensional terrain (3D terrain), which includes the ground, walls and ceiling. Then, we demonstrate with computer simulation that we can selectively leverage GDA and coupled drive by walking posture control.

scholarly journals Mechatronic Control System for a Compliant and Precise Pneumatic Rotary Drive Unit

Actuators ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
Johannes T. Stoll ◽  
Kevin Schanz ◽  
Andreas Pott
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Mechanical Design ◽  
Control Algorithms ◽  
Field Oriented Control ◽  
Pneumatic Drive ◽  
Drive Unit ◽  
Control Approach ◽  
Human Robot Collaboration ◽  
Rotary Drive

Robots that enable safe human-robot collaboration can be realized by using compliant drive units. In previous works, different mechanical designs of compliant pneumatic rotary drive units with similar characteristics have been presented. In this paper, we present the overall control approach that we use to operate one of these compliant pneumatic rotary drive units. We explain the mechanical design and derive the differential equation that describes the dynamics of the system. In order to successfully operate a pneumatic drive unit with three or more working chambers, the torque specified by the controller has to be split up onto the working chambers. We transfer the well-known field-oriented control approach from electric motors to the investigated pneumatic drive unit to create such a torque mapping. Moreover, we develop optimized torque mappings that are tailored to work with this type of drive unit. Furthermore, we introduce and compare two control algorithms based on different implementations of state feedback to realize position control. Finally, we present the step responses that we achieve when we implement either one of the control algorithms in combination with the different torque mappings.

Design and Underwater Tests of Subsea Walking Hexapod MAK-1

2016 ◽  
Author(s):  
Vadim V. Chernyshev ◽  
Vladimir V. Arykantsev ◽  
Andrey E. Gavrilov ◽  
Yaroslav V. Kalinin ◽  
Nikolay G. Sharonov
Keyword(s):  
Movement Control ◽  
Experimental Tests ◽  
Energy Usage ◽  
Walking Machine ◽  
Walking Machines ◽  
Sea Bottom ◽  
Different Types ◽  
Robotic Devices ◽  
And Control ◽  
System Power

An important role among machines for sea bottom exploration is assigned to the autonomous ground devices. Some rescue tasks also require subsea robotic devices. The main purpose of the work is to investigate and improve adaptive characteristics, traction properties and control methods of cyclic walking movers in underwater conditions. Traction properties of walking machines, which moves at sea bottom was analyzed. Some experience of development and experimental tests of the walking robot “Vosminog”, designed for work at weak and waterlogged grounds. Dynamic model of a walking machine has been shown. Studied an opportunity to increase adaptive characteristics and shape passableness of walking machines. Also design and results of underwater tests of subsea walking unit MAK-1 are discussed. During tests the performance of a walking unit has been checked and the influence of design features of a walking mover on its traction characteristics and ground passability has been investigated. Some details about control system, power system and energy usage, vertical motions and accelerations for different types of walking and conditions of movement has been given. Also, certain attention was given to testing of methods of standalone movement control of subsea unit in conditions of incomplete and ambiguous vision of current situation. Tests have shown that walking movers in subsea conditions can provide higher traction properties, in comparison with wheeled and tracked ones. The unit can be used for exploration of seabed resources and for rescue tasks.

How to achieve precise operation of a robotic manipulator on a macro to micro/nano scale

2017 ◽  
Vol 37 (2) ◽  
pp. 186-199 ◽  
Author(s):  
Zhiqiang Yu ◽  
Qing Shi ◽  
Huaping Wang ◽  
Ning Yu ◽  
Qiang Huang ◽  
...  
Keyword(s):  
Control Algorithm ◽  
Mechanical Design ◽  
Robotic Manipulator ◽  
Control Algorithms ◽  
General Control ◽  
Content Type ◽  
Mechanical Parts ◽  
Accurate Perception ◽  
And Control ◽  
Made In

Purpose The purpose of this paper is to present state-of-the-art approaches for precise operation of a robotic manipulator on a macro- to micro/nanoscale. Design/methodology/approach This paper first briefly discussed fundamental issues associated with precise operation of a robotic manipulator on a macro- to micro/nanoscale. Second, this paper described and compared the characteristics of basic components (i.e. mechanical parts, actuators, sensors and control algorithm) of the robotic manipulator. Specifically, commonly used mechanisms of the manipulator were classified and analyzed. In addition, intuitive meaning and applications of its actuator explained and compared in details. Moreover, related research studies on general control algorithm and visual control that are used in a robotic manipulator to achieve precise operation have also been discussed. Findings Remarkable achievements in dexterous mechanical design, excellent actuators, accurate perception, optimized control algorithms, etc., have been made in precise operations of a robotic manipulator. Precise operation is critical for dealing with objects which need to be manufactured, modified and assembled. The operational accuracy is directly affected by the performance of mechanical design, actuators, sensors and control algorithms. Therefore, this paper provides a categorization showing the fundamental concepts and applications of these characteristics. Originality/value This paper presents a categorization of the mechanical design, actuators, sensors and control algorithms of robotic manipulators in the macro- to micro/nanofield for precise operation.

The Mechanics of Parallel Mechanisms and Walking Machines

1994 ◽  
Vol 208 (6) ◽  
pp. 367-377 ◽  
Author(s):  
S J Zhang ◽  
D J Sanger ◽  
D Howard
Keyword(s):  
Parallel Mechanism ◽  
Virtual Work ◽  
The Body ◽  
Position Vector ◽  
Parallel Mechanisms ◽  
Active Joint ◽  
End Effector ◽  
Walking Machine ◽  
Walking Machines ◽  
Fixed Base

A parallel mechanism is one whose links and joints form two or more serially connected chains which join the fixed base and the end effector The mechanism of a multi-legged walking machine can be considered as a parallel mechanism whose base is not fixed and whose configuration changes during different phases of its gait. This paper presents methods for analysing the mechanics of parallel mechanisms and walking machines using vector and screw algebra Firstly, displacement analysis is covered; this includes general methods for deriving the position vector of any joint in any leg and for calculating the active joint displacements in any leg. Secondly, velocity analysis is covered which tackles the problem of calculating active joint velocities given the velocity, position and the orientation of the body and the positions of the feet. Thirdly, the static analysis of these classes of mechanisms using the principle of virtual work and screw algebra is given. Expressions are derived for the actuator forces and torques required to balance a given end effector (or body) wrench and, in the case of a walking machine, the ground reactions at the feet. Numerical examples are given to demonstrate the application of these methods.

Optimal tripod turning gait generation for hexapod walking machines

Robotica ◽  
2000 ◽  
Vol 18 (6) ◽  
pp. 639-649 ◽  
Author(s):  
S. Miao ◽  
D. Howard
Keyword(s):  
Rotation Angle ◽  
Gait Generation ◽  
Walking Machine ◽  
Walking Machines ◽  
Machine Layout ◽  
The Stability

This paper describes an algorithm for generating a tripod turning gait which, when given an arbitrarily located turning centre, firstly maximises the rotation angle (angular stride) and then secondly optimises the stability. It does not require a specific walking machine layout or leg workspace shape, and it can deal with changes in the position of the CG caused by walking on a gradient or by uneven loading.

Basic Design and Synchronized Motion Control for Hexapod Walking Machine

1993 ◽  
Vol 5 (6) ◽  
pp. 511-515
Author(s):  
Katsuhiko Inagaki ◽  
◽  
Hisato Kobayashi
Keyword(s):  
Motion Control ◽  
Distributed Control ◽  
Gasoline Engine ◽  
High Energy ◽  
Basic Design ◽  
Walking Machine ◽  
Walking Machines ◽  
Clutch System ◽  
High Energy Efficiency ◽  
Electromagnetic Clutch

This paper discusses a new mechanism and a new method of motion control for a multi-legged walking machine. The new mechanism provides high energy efficiency which is one of the most important points of walking machines. This problem is solved combining a gasoline engine and an electromagnetic clutch system. In addition, synchronized motion control is also proposed for this mechanism. This control is based on the notion of an autonomous distributed control. Thus, this system has sufficient flexibility and reliability.

Modeling and Mechanical Design of an Active-Caster Omnidirectional Mechanism with a Ball Transmission

2018 ◽  
Vol 30 (6) ◽  
pp. 910-919 ◽  
Author(s):  
Kosuke Kato ◽  
◽  
Masayoshi Wada
Keyword(s):  
Power Distribution ◽  
Control Function ◽  
Mechanical Design ◽  
Computer Control ◽  
Single Layer ◽  
Control Algorithms ◽  
Angle Sensor ◽  
Simple Motor ◽  
Point Control ◽  
Point To Point

This paper presents kinematic and static analyses of an active-caster robotic drive with a single-layer ball transmission (ACROBAT-S). On the basis of the analyses, a single-wheel prototype is designed, and fundamental experiments using the prototype are conducted. The proposed ACROBAT-S includes a ball transmission that transmits power to a wheel axis and steering axis of an active-caster wheel in an appropriate ratio to produce so-called “caster motion.” The power distribution is realized mechanically rather than by complicated computer control algorithms. Therefore, the angle sensor for detecting the wheel orientation, and the control calculations for coordinated control of the wheel and steering motors of a conventional system are eliminated. Thus, the proposed mechanical design, which transfers a part of the control function to the mechanism, contributes to simplifying the overall control system. The results of the analyses and experiments with a prototype confirm that the proposed active-caster mechanism, ACROBAT-S, can realize the expected omnidirectional motion with simple motor control, such as Point-To-Point control.

scholarly journals Comparison of Contact Force Control Strategies on Different Robot Arm Types

2010 ◽  
Author(s):  
Hu¨seyin Yaltirik ◽  
A. Kerim Kar ◽  
Bu¨lent Ekici
Keyword(s):  
Force Control ◽  
Control Algorithm ◽  
Control Strategies ◽  
Control Algorithms ◽  
Robot Arm ◽  
Interaction Forces ◽  
Static Contact ◽  
Contact Tasks ◽  
Control Interaction ◽  
Contact Force Control

Nowadays robots are used in various areas. There are extremely important applications where the robot arm tip comes in contact with the environment or an object. During controlling an object, static or in motion, the object or the robot arm should not be damaged. The interaction forces are important in such conditions. Whether the task succeeds or fails depends on how accurate the interaction forces are controlled. The interaction forces are changed depending on the motion of the robot arm. Therefore, to control interaction forces a force control algorithm must be developed. In this research a force control algorithm will first be developed for the quasi-static contact tasks, then it will be extended to the dynamic cases. The goal of this study is to compare force control strategies to achieve the desired interaction forces between the robot arm tip (end-effector) and the environment during contact tasks. Taguchi L9 method is used for comparison of selected force control algorithms which are modeled in SIMULINK MATLAB program.

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