Design and optimization of a dual quadruped vehicle based on whole close-chain mechanism

Abstract

A new ''whole close-chain mechanism'' concept is proposed for the design of the modular legged unit of walking vehicles. Based on this concept, the walking vehicle called dual quadruped vehicle is developed and constructed. The vehicle designed as an omnidirectional carrying platform contains two identical single-driven quadruped mechanisms. The details of the design procedure are given, including the single close-chain legged mechanism, the modular legged unit, and the dual quadruped vehicle. The construction description of the single leg is presented. With the optimum design of the whole close-chain legged mechanism, the two foot-point characteristic trajectories are investigated. Based on the strategies of the legged module integration, the best phase configuration in pitching movement and the steering analysis are discussed and illustrated. Dynamic simulations and experiments are performed to verify the validity of the theoretical analysis of the new concept and the maneuverability of the vehicle prototype.

Design and analysis of a novel multi-legged horse-riding simulation vehicle for equine-assisted therapy

“…According to the characteristics of the topological structure 27 and the creative mechanism design method 28 of the planar kinematic chain, we proposed the single close-chain legged mechanism through the particularization of the feasible specialized chain. The full-pivot legged mechanism with bionic characteristics is shown in Figure 2.…”

“…In consideration of these above-mentioned conditions, we provided five pre-assigned points (marked with circles in Figure 4) on the desired foot trajectory, and the x pi and y pi are x and y components of the pre-assigned points. The objective function is expressed as equation (3), and we obtained the optimal solutions using the sequence quadratic program 27 in Matlab™. The optimum values of the linkages are described in Table 1.…”

“…18 In general, the open-loop legged robots, such as BigDog, 19 DANTE II, 20 and ASIMO, 21 have greater degrees of freedom (DoFs), which require more actuators, while the closed-loop legged robots, such as the mechanical horse, 22 Chebyshev mechanism, Theo Jansen mechanism, 23 Klann mechanism, 24 and rehabilitation studies of wooden ox and horse, 25,26 have fewer DoFs. In order to enhance the mobility and the carrying capability of the closed-loop legged mechanism, in our previous work, the “whole close-chain mechanism” 27 integrated by modules of single-DoF planar linkages has been proposed. The study analyzed two foot-point trajectories, pitching motion and steering motion of a multi-legged vehicle.…”

Simulation and analysis of a single actuated quadruped robot

“…Wu et al (2019) combined four groups of quadruped robots into a 16-legged platform, which can perform turning and other functions through the interaction of four motors. Wu et al (2017) analyzed the single leg structure by using the closed-vector method and optimized the parameters of the single leg structure. Then they studied a fully closed leg device and walking vehicle and produced the detailed design process of a single, closed-loop leg mechanism, a modular leg unit and a double quadruped robot (Wu and Yao, 2018a;Wu et al, 2021).…”

Research on a ø6m TBM Steel Arch Splicing Manipulator

“…At present, researches on single-DOF closed-loop mechanism are mainly focused on leg mechanism and gripper mechanism [ 20 ]. Studies of closed-loop planar mechanisms such as Chebyshev Mechanism [ 21 ], Klann Mechanism [22], LARM BiPED Mechanism [23] and DQV [24] have shown that the closed-loop series structure possesses the integral rigidity, more suitable for missions under a high load, and it performs better at high stride frequency [25,26].Liu [27] designed a single DOF robot leg mechanism intended for tailed quadruped locomotion.…”