Parameter design and optimization for mobile mechanism of a transformable wheel-track robot

Wheeled walking mechanism has the advantages of high mobility and low rolling resistance, but it is easy to sink and slip when working in soft and muddy terrain. Tracked walking mechanism has the advantages of high passability and stability, but it has the problems of difficult steering and slow walking speed. In order to make the walking mechanism possess a combination of passability, stability, and mobility, a coordinated variable wheel-track walking mechanism was designed. The coordinated variable triangle track can change the landing area through the deformation structure to improve the ability of the walking mechanism to adapt to different terrains. The kinematics equation of the wheel-track walking mechanism was established, and the front wheel steering angle equation during motion was derived. Based on RecurDyn software, the motion simulation of the walking mechanism was carried out under the conditions of straight walking and turning on the flat ground, climbing hillsides, and crossing ditches. The simulation results show that the coordinated variable wheel-track walking mechanism has the mobility of wheeled walking mechanism and the passability and stability of the tracked walking mechanism. The stability and climbing ability of the wheel-track walking mechanism was better when the coordinated variable triangle track in the stretch state, and the mobility and steering ability was better in the contraction state.

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“…Substituting from equation (4) into equation 7, and dividing both sides by Dt. At the same time, taking the limit of Dt, we get…”

Section: Design Of Wheel-track Walking Mechanismmentioning

confidence: 99%

Design and kinematics analysis of coordinated variable wheel-track walking mechanism

Zang

Yang

et al. 2020

International Journal of Advanced Robotic Systems

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“…A more automated version of such an implementation employs a mechanism that toggles between wheels and tracks [32], [33] with the possibility of integrating belt-driven front and back flippers [34] to enable legged locomotion for military applications. Additional variations include articulated wheels that can be reconfigure into legs [35], [36], and articulated tracks [37] that can reshape into wheels.…”

Section: 2mentioning

confidence: 99%

Design of a Multi-Directional Hybrid-Locomotion Modular Robot With Feedforward Stability Control

Kumar

Saab

Ben-Tzvi

2017

Volume 5B: 41st Mechanisms and Robotics Conference

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This paper presents the design of a modular robot capable of multi-directional mobility to aid reconfiguration on uneven terrain. Modular reconfigurable robotic systems consist of a large number of self-sufficient modules that can dock and reconfigure to scale locomotion and manipulation capabilities. However, on uneven terrains, reconfigurable robots face challenges due to the requirement of precise alignment between modules during the docking procedure. First, a survey of current modular reconfigurable robots is presented, analyzing their strengths and shortcomings in reconfiguration and mobility. A novel design is formulated that features a hybrid combination of wheels and tracks, symmetrically assembled about the front and right planes, providing multi-directional mobility and modularity. The robot can move over uneven terrain via tracks, move at higher speeds via wheels placed orthogonally to the tracks, and move in the vertical direction via a vertical translation mechanism in order to aid in multi-robot docking. Both the wheels and tracks possess yaw mobility via differential drive. The design’s compact size and hybrid multi-directional mobility system make the robot highly mobile on uneven terrain. Presented in this paper are the mechanical and electrical design and a feedforward dynamic stability controller, the performance of which is validated using a simulated case study.

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“…As shown in Figure 6, each TWT unit is composed of a transformable track mechanism and a drive wheel mechanism. In some early works, we studied the design method of its structure parameters and proved their reasonability by the method of theatrical analysis, simulation, and basic experiments [16][17][18]. Table 1 lists some primary design parameters for the mobile mechanism.…”

Section: Kinematic Relation Analysis For Parts Of the Twt Unitmentioning

confidence: 99%

Analysis of the constraint relation between ground and self-adaptive mobile mechanism of a transformable wheel-track robot

et al. 2011

Sci. China Technol. Sci.

Self Cite

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To maneuver in unstructured terrains where the ground might be soft, hard, flat or rough, a transformable wheel-track robot (NEZA-I) with a self-adaptive mobile mechanism is proposed and developed. The robot consists of a control system unit, two symmetric transformable wheel-track (TWT) units, and a rear-wheel unit. The TWT unit is the main mobile mechanism for the NEZA-I robot, with the rear-wheel unit acting as an assistant mechanism. Driven only by one servomotor, each TWT unit can efficiently select between track mode and wheel mode for optimal locomotion, autonomously switching locomotion mode and track configuration with changes in the terrain. In this paper, the mechanism structure, the self-adaptive drive system, the locomotion mode and posture of the NEZA-I robot are presented, the kinematic relation of the inside parts of the TWT unit is analysed, and the mathematic model of the constraint relation between the mobile mechanism and the ground, abbreviated to "MGCR model" is set up for the NEZA-I robot to go through some typical unstructured environments. The mechanism parameters, which influence the self-adaptability of the NEZA-I robot, are found and optimized. Basic experiments show that the mobile mechanism has the self-adaptability to navigate in unstructured terrains and has superior obstacle-negotiating performance, and that the MGCR model and the analysis method of mechanism parameters are reasonable. From a mechanism point of view, it can provide an idea for research on the adaptive control of the robot.self-adaptive mobile mechanism, transformable track, wheel-track hybrid robot, mechanism design Citation:Li Z Q, Ma S G, Li B, et al. Analysis of the constraint relation between ground and self-adaptive mobile mechanism of a transformable wheel-track robot.

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Parameter design and optimization for mobile mechanism of a transformable wheel-track robot

Cited by 9 publications

References 9 publications

Design and kinematics analysis of coordinated variable wheel-track walking mechanism

Design and kinematics analysis of coordinated variable wheel-track walking mechanism

Design of a Multi-Directional Hybrid-Locomotion Modular Robot With Feedforward Stability Control

Analysis of the constraint relation between ground and self-adaptive mobile mechanism of a transformable wheel-track robot

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