The Motion Control And Related Research Of Autonomous Legged Robot

Because of the advantage of structure, the work area of autonomous legged robot is broader than that of crawler robot and wheeled robot. Autonomous legged robot often works in dynamic uncertain environment; it's a great challenge for legged robot in locomotion, flexibility and real-time walking status recognition. A lot of research results have been achieved in locomotion design and walking stability. But, with the development of robot technology and the enhanced performance of robot platform, the task is also more complicated than before, and the higher demand is put forward in walking design, walking status analysis and calibration for autonomous legged robot. In order to improve the walking speed of legged robot and increase the capability of legged robot to understand its own status in high-speed movement to enhance robot work ability in unknown environment, with the research platform, quadrupedal robot AIBO, this paper studies the locomotion control of autonomous legged robot in the following three aspects:1. The gait locus generation and optimization of legged robotIn the previous walking design of legged robot which is based on gait design, the rectangle locus and trapezoid locus are often used after the leg model building and inverse kinematic, the lack of research of optimization gait locus makes it difficult for the walking design to work well in different environments and conditions. Based on the gait design, this paper presents a curve fitting planning method to generate the gait locus in the work space of the limb of legged robot while incorporating genetic algorithms, it makes legged robot search gait locus automatically to enhance the robot movement ability.2. The walking state analysis model of legged robotWith the development of legged robot walking speed, the higher demand of walking stability has been put forward. Many research results concentrate on whether turnover is occurred, lack of ideas about the quantitative description of collision and walking stability. Bearing this problem in mind, this paper presents a possibility walking state analysis model for legged robot which is based on the feedback of acceleration sensor. The feedback of acceleration sensor is processed by Discrete Fourier Transform while incorporating the dynamic analysis of the walking of legged robot firstly, then, according to be estimated by Mahalanobis Distance, the result can express the legged robot walking status quantitatively. Using quadrupled robots as a platform for evaluation, this model is shown to be able to descript the walking of legged robot and express the walking status in real time, and it could be helpful for legged robot to adjust its locomotion with the change of environment to ensure the walking stability of legged robot.3. A self-calibration walking state model of legged robotThe walking of legged robot is more complicated than crawler robot and wheeled robot, the walking state calibration for legged robot is very important, especially when motion is changed rapidly, so the on-line walking state model self-calibration capability of legged robot must be enhanced to increase the capability of understanding its own status in high-speed movement. With the idea of improving the calibration capability of legged robot, by combining the motion model of paper[79] and the walking state model which is based on acceleration sensor, this paper presents a self-calibration model for the walking state of legged robot. Utilizing the inter-calibration between motion model and sensor model, legged robot can on-line self-calibrate its own walking state.Using quadrupled robots as a platform for evaluation, this paper makes the experimental study in the three research aspects and achieves good results. The experimental results show that the gait locus generation method can improve the walking speed of legged robot effectively, the walking state model which is based the feedback of acceleration sensor can descript the walking stability of legged robot quantitatively, and the self-calibration walking model make legged robot be able to calibrate its own walking state online.Through the three aspects, this paper studies in the walking design, optimization, identification of walking state and self-calibration of walking state model of autonomous legged robot. The research results improve the walking design of legged robot, enhance the performance of legged robot with the capability of understanding its own walking status and make legged robot be able to adapt to different environments.