Muscle roles on directional change during hopping of a biomimetic feline hindlimb

Cats, from tiny domestic cats (Felix Catus) to big tigers (Panthera Tigris), are well known for their great acrobatic skills and hunting ability. Aiming to better understand how the feline family interacts with the environment, we adopt a biomimetic approach on a hopping feline hindlimb. Using air muscles to simulate the compliance of biological muscles, this robotic hindlimb has seven muscles and changes hopping direction. We individually evaluate and estimate muscles contribution to the jumping direction. Finally, we successfully control the hopping direction using a non-linear curve fitting from experimental results, hopefully contributing to the understanding of our biological counterpart.This work was partially supported by KAKENHI Kiban(S) 23220004This is the accepted manuscript. The final version's available at http://dx.doi.org/10.1109/ROBIO.2012.6491108

Investigating balance control of a hopping bipedal robot

Legged robots are dynamic moving machines that are potentially able to traverse through rough terrain which is inaccessible for wheeled or tracked vehicles. For bipedal robots, balancing control while hopping/running is challenging, especially when the foot contact area is small. Servo hydraulics is highly suitable for robot leg actuation due to its high power density and good power-to weight ratio. This paper presents a controller for a hydraulically actuated bipedal robot, the Bath Bipedal Hopper (BBH). The controller follows the well-established structure of the ‘Three-part’ control algorithm. The three parts are: hopping height control; longitudinal velocity control by changing the leg angle during the flight phase to place the foot in the desired position; and body attitude correction during the stance phase. Simulation results from a detailed non-linear model indicate that this controller can successfully balance the hydraulic robot while hopping with different longitudinal velocities

Simulation of the Landing Buffer of a Three-Legged Jumping Robot

In recent years, the research of planetary exploration robots has become an active field. The jumping robot has become a hot spot in this field. This paper presents a work modelling and simulating a three-legged jumping robot, which has a powerful force, high leaping performance, and good flexibility. In particular, the jumping of the robot was simulated and the landing buffer of the robot was analyzed. Because this jumping robot lacks landing buffer, this paper verifies a method of absorbing landing kinetic energy to improve landing stability and storing it as the energy for the next jump in the simulation. Through the landing simulation, the factors affecting the landing energy absorption are identified. Moreover, the simulation experiment verifies that the application of the intermediate axis theorem helps to absorb more energy and adjust the landing attitude of the robot. The simulation results in this paper can be applied to the optimal design of robot prototypes and provide a theoretical basis for subsequent research

A new mechanical design for legged robots to reduce energy consumption

Many legged robots have been designed and built by universities, research institutes and industry; however, few investigations regard energy consumption as a crucial design criterion. This paper presents a novel configuration for legged robots to reduce the energy consumption. The proposed leg can be either used as a single leg or easily attached to bodies with four, six and eight legs. This mechanism is a parallel four-bar linkage equipped with one active and four passive joints. In fact, the usage of the passive elements leads to simple feed-forward control paradigms. Moreover, another distinctive feature of this design is the arrangement of one-way clutches and flat springs to store the potential energy for utilizing it in the next step. A locomotion prototype of the proposed mechanical structure is built and its simulation is also presented in this paper. Comparing the results with other structures demonstrates the superiority and efficiency of this work regarding energy consumption problem.</p

生物の二関節間筋腱複合体を規範とした脚ロボットの開発

電気通信大学201

A new rotary actuator capable of rapid motion using an antagonistic cam mechanism

Animals can achieve agile behaviors such as jumping and throwing in addition to flexible behaviors with the same musculoskeletal systems, and those movements can extend the range of their activities. We have been working on actuators capable of rapid and flexible motions learning the musculoskeletal systems. In this paper, we propose a new rotary actuator using a pair of motors, springs, and cams to perform three functions, namely, normal motion, rapid or instantaneous motion, and rigidity control using an antagonistic cam mechanism, and describe the operating principle of the proposed mechanism, the mathematical model of the mechanism during rapid motion, and the design principle of the cam, which is a key mechanical element in this mechanism. Finally, we present an analysis of the error between the theoretical the measurement results during rapid motion

Squat vertical jump of a 3DOF robot leg over an inclined plane: analysis with joint torque profile approximation

This work shows an analysis of the movement of a robot with an articulated leg (without a toe) of 3 degrees of freedom (3DOF) when performing a squat vertical jump over an inclined plane. We propose two different approaches to model this problem. The first method estimates the ankle position and foot orientation at the landing time, using the non-zero angular momentum and the plane tilt angle; thus, the foot orientation can be corrected during the time in the air, which achieves greater contact area when the robot land. The second method adjusts the relative position of the CoM (Center of Mass) to the horizontal axis in order to infer the joint torque profile in different tilt angles of the plane. Matlab simulation results show that, the ankle is the most affected joint whereas the plane tilts with the same jump pattern. Having a range of inclination values of ± #960;/18, the torque variation changes from 35.82% to 2.59%, which proves the efficiency of the evaluated cases1618087COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES99999.006184/2015-0