Conceptual Design and Computational Modeling Analysis of a Single-Leg System of a Quadruped Bionic Horse Robot Driven by a Cam-Linkage Mechanism

Abstract

In this study, the configuration of a bionic horse robot for equine-assisted therapy is presented. A single-leg system with two degrees of freedom (DOFs) is driven by a cam-linkage mechanism, and it can adjust the span and height of the leg end-point trajectory. After a brief introduction on the quadruped bionic horse robot, the structure and working principle of a single-leg system are discussed in detail. Kinematic analysis of a single-leg system is conducted, and the relationships between the structural parameters and leg trajectory are obtained. On this basis, the pressure angle characteristics of the cam-linkage mechanism are studied, and the leg end-point trajectories of the robot are obtained for several inclination angles controlled by the rotation of the motor for the stride length adjusting. The closed-loop vector method is used for the kinematic analysis, and the motion analysis system is developed in MATLAB software. The motion analysis results are verified by a three-dimensional simulation model developed in Solidworks software. The presented research on the configuration, kinematic modeling, and pressure angle characteristics of the bionic horse robot lays the foundation for subsequent research on the practical application of the proposed bionic horse robot.

Dynamic Margins of Stability During Robot-Assisted Walking in Able-Bodied Individuals: A Preliminary Study

“…Previously, walking performance involving RE-assisted gait has included clinical measures, functional measures, and gait analysis studies focused primarily on spatiotemporal and lower limb kinematic outcomes during quadrupedal gait using inverse dynamic techniques (Sylos-Labini et al, 2014; Ramanujam et al, 2017, 2018, 2019a,b; Husain et al, 2018;Forrest et al, 2019;Wang et al, 2019). Moreover, our group has not only published articles on upper and lower extremity kinematics but also studied the posture and balance of individuals (both SCI and AB controls) during RE-assisted gait with forearm crutches by examining their instantaneous CoM excursions (whole body, trunk, and lower extremity) in relation to the BoS (Ramanujam et al, 2019a,b).…”

“…During RE walking (especially, EksoGT TM ), the devices' limitation toward choosing the desired lateral foot placement puts more emphasis on crutch location outside the leading limb to provide a stable BoS, resulting in reduced ML control of stability. The location of this crutch may also be influenced by the different surfaces (e.g., carpet, pavement) (Wang et al, 2019).…”

“…Therefore, understanding the posture and balance control strategies during robotic exoskeleton (RE) gait compared to independent OG walking is crucial in ensuring the safety of these individuals and preventing falls. Although researchers have studied the kinematic, spatiotemporal, cardiopulmonary, cognitive, neuromuscular, and safety outcomes associated with RE training (Nozaki et al, 2005;Sayenko et al, 2015;Miller et al, 2016;Ramanujam et al, 2017Ramanujam et al, , 2018Ramanujam et al, , 2019aSaleh et al, 2017;Gordon et al, 2018;Tefertiller et al, 2018;Forrest et al, 2019;Guanziroli et al, 2019;Khan et al, 2019;Luger et al, 2019;Momeni et al, 2019;Wang et al, 2019;Yildirim et al, 2019;McIntosh et al, 2020), a thorough assessment of dynamic stability during RE walking is important to understanding the mechanics of human-machine interactions during exoskeleton-assisted gait and the potential to lower fall risk.…”

Optimization and synthesis of a cam-linkage mechanism with a swing follower with variable pivot

“…The engineering applications of the cam-linkage mechanisms are very wide, including cutting and forming presses, package machinery, textile machinery, sew machines, bionic robots, and all types of automatic production equipment. [1][2][3][4][5] For a long time, the design of cam-linkage mechanisms has been intensively investigated. Cardona and G eradin 6 investigated the kinematics and dynamics of mechanisms with cams.…”

Design and Analysis of the Bionic Mechanical Foot with High Trafficability on Sand

“…For example, Boston Dynamics has made great progress in quadruped bionic robot, and has successively developed BigDog, LS3, WildCat, Spot, and SpotMini [10][11][12][13]. Besides, Cheetah, HyQ, and ASLP also promoted the development of quadruped bionic robots [14][15][16][17][18]. Osaka University designed the "Asterisk" hexapod robot with spider as a bionic prototype [19], and NASA designed the "LEMUR" hexapod bionic robot with crab as a bionic prototype [20].…”