Type Synthesis for Bionic Quadruped Walking Robots

2015 ◽  
Vol 12 (4) ◽  
pp. 527-538 ◽  
Author(s):  
Jun He ◽  
Feng Gao
Keyword(s):  
Walking Robots ◽  
Type Synthesis

Complexity Criteria for the Preliminary Design Stage of Walking Robots

2017 ◽  
Author(s):  
Da Xi ◽  
Feng Gao
Keyword(s):  
Walking Robots ◽  
Design Stage ◽  
Structure Parameters ◽  
Preliminary Design ◽  
Walking Robot ◽  
Type Synthesis ◽  
End Effector ◽  
Iterative Design ◽  
Preliminary Design Stage ◽  
Kinematic Performance

This paper introduces several complexity-based criteria for walking robots at the preliminary design stage. The motivation lies in filtering optimal leg types or body layouts to reduce cost at later iterative-design stage. Several qualitative or semi-quantitative criteria are proposed for walking robot designers. For different type-synthesis results of robot legs, three criteria are proposed named the uncertainty of the end-effector, the complexity of control and the complexity of movement. For different layouts of robot bodies, two kinematic criteria are proposed named the complexity of translation and the complexity of rotation. These criteria could together judge the kinematic performance or potential for a walking robot with the least structure parameters at the conceptual-design stage. Several prototypes in the researchers’ lab are evaluated with the criteria, and the results are compared with the experimental data to proof the validity.

Type synthesis of a class of novel 3-DOF single-loop parallel leg mechanisms for walking robots

2020 ◽  
Vol 145 ◽  
pp. 103695 ◽  
Author(s):  
Luquan Li ◽  
Yuefa Fang ◽  
Sheng Guo ◽  
Haibo Qu ◽  
Lin Wang
Keyword(s):  
Walking Robots ◽  
Type Synthesis ◽  
Single Loop ◽  
Leg Mechanisms

Multifunctional Electroelastomer Roll Actuators and Their Application for Biomimetic Walking Robots

2003 ◽  
Author(s):  
Qibing Pei ◽  
Marcus Rosenthal ◽  
Ron Pelrine ◽  
Scott Stanford ◽  
Roy Kornbluh
Keyword(s):  
Walking Robots

scholarly journals Type Synthesis of 1T2R Parallel Mechanisms Using Structure Coupling-Reducing Method

2019 ◽  
Vol 32 (1) ◽  
Author(s):  
Haitao Liu ◽  
Ke Xu ◽  
Huiping Shen ◽  
Xianlei Shan ◽  
Tingli Yang
Keyword(s):  
Explicit Form ◽  
Parallel Mechanism ◽  
Analytic Solutions ◽  
Forward Kinematics ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Real Time Control ◽  
Time Control ◽  
Topological Characteristics ◽  
Zero Coupling

Abstract Direct kinematics with analytic solutions is critical to the real-time control of parallel mechanisms. Therefore, the type synthesis of a mechanism having explicit form of forward kinematics has become a topic of interest. Based on this purpose, this paper deals with the type synthesis of 1T2R parallel mechanisms by investigating the topological structure coupling-reducing of the 3UPS&UP parallel mechanism. With the aid of the theory of mechanism topology, the analysis of the topological characteristics of the 3UPS&UP parallel mechanism is presented, which shows that there are highly coupled motions and constraints amongst the limbs of the mechanism. Three methods for structure coupling-reducing of the 3UPS&UP parallel mechanism are proposed, resulting in eight new types of 1T2R parallel mechanisms with one or zero coupling degree. One obtained parallel mechanism is taken as an example to demonstrate that a mechanism with zero coupling degree has an explicit form for forward kinematics. The process of type synthesis is in the order of permutation and combination; therefore, there are no omissions. This method is also applicable to other configurations, and novel topological structures having simple forward kinematics can be obtained from an original mechanism via this method.

scholarly journals Neural Network Based Contact Force Control Algorithm for Walking Robots

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 287
Author(s):  
Byeongjin Kim ◽  
Soohyun Kim
Keyword(s):  
Neural Network ◽  
Contact Force ◽  
Force Control ◽  
Control Algorithm ◽  
Position Control ◽  
Linear Quadratic Regulator ◽  
Walking Robots ◽  
Test Model ◽  
Linear Quadratic ◽  
Contact Force Control

Walking algorithms using push-off improve moving efficiency and disturbance rejection performance. However, the algorithm based on classical contact force control requires an exact model or a Force/Torque sensor. This paper proposes a novel contact force control algorithm based on neural networks. The proposed model is adapted to a linear quadratic regulator for position control and balance. The results demonstrate that this neural network-based model can accurately generate force and effectively reduce errors without requiring a sensor. The effectiveness of the algorithm is assessed with the realistic test model. Compared to the Jacobian-based calculation, our algorithm significantly improves the accuracy of the force control. One step simulation was used to analyze the robustness of the algorithm. In summary, this walking control algorithm generates a push-off force with precision and enables it to reject disturbance rapidly.

scholarly journals A New Method for Type Synthesis of 2R1T and 2T1R 3-DOF Redundant Actuated Parallel Mechanisms with Closed Loop Units

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Yongquan Li ◽  
Yang Zhang ◽  
Lijie Zhang
Keyword(s):  
Closed Loop ◽  
Screw Theory ◽  
Line Graph ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Allocation Criteria ◽  
Grassmann Line Geometry ◽  
Moving Platform ◽  
Atlas Method

Abstract The current type synthesis of the redundant actuated parallel mechanisms is adding active-actuated kinematic branches on the basis of the traditional parallel mechanisms, or using screw theory to perform multiple getting intersection and union to complete type synthesis. The number of redundant parallel mechanisms obtained by these two methods is limited. In this paper, based on Grassmann line geometry and Atlas method, a novel and effective method for type synthesis of redundant actuated parallel mechanisms (PMs) with closed-loop units is proposed. Firstly, the degree of freedom (DOF) and constraint line graph of the moving platform are determined successively, and redundant lines are added in constraint line graph to obtain the redundant constraint line graph and their equivalent line graph, and a branch constraint allocation scheme is formulated based on the allocation criteria. Secondly, a scheme is selected and redundant lines are added in the branch chains DOF graph to construct the redundant actuated branch chains with closed-loop units. Finally, the branch chains that meet the requirements of branch chains configuration criteria and F&C (degree of freedom & constraint) line graph are assembled. In this paper, two types of 2 rotational and 1 translational (2R1T) redundant actuated parallel mechanisms and one type of 2 translational and 1 rotational (2T1R) redundant actuated parallel mechanisms with few branches and closed-loop units were taken as examples, and 238, 92 and 15 new configurations were synthesized. All the mechanisms contain closed-loop units, and the mechanisms and the actuators both have good symmetry. Therefore, all the mechanisms have excellent comprehensive performance, in which the two rotational DOFs of the moving platform of 2R1T redundant actuated parallel mechanism can be independently controlled. The instantaneous analysis shows that all mechanisms are not instantaneous, which proves the feasibility and practicability of the method.

Sign in / Sign up

Export Citation Format

Share Document