Kejie Li

Kinematics mapping and similarity evaluation of humanoid motion based on human motion capture

The captured data must be adapted for the humanoid because its kinematics and dynamic differ from those of the human actor. The kinematics constraints such as ground contact conditions are crucial for humanoid locomotion. Furthermore, it is desirable that the humanoid motion have of high similarity with those of the human actor. In this paper, first the similarity function of the humanoid motion is proposed. Then, the kinematics constrains including ground contact conditions are formulated, and the algorithm to derive the humanoid motion with a high similarity and satisfying kinematics constraints is present. Finally, the effectiveness is confirmed by the experiment of Chinese Kungfu Taiji using our developed 33 DOF humanoid robot.

Suction Ability Analyses of a Novel Wall Climbing Robot

The wall climbing robot has characteristics of moving smartly and suction reliably on the wall, therefore, this paper proposes a method called critical suction, based on the negative suction and thrust force. Then mechanics, the robots suction mechanism and the performance of air-sealed are analyzed, and the critical suction mechanism is discussed in theory. Furthermore, the fluid model and the fluid network dynamic model of the robots suction system are set up. According to the dynamic response equation of the negative pressure in the suction cup, the suction process of the robot on the wall is simulated. Finally, the effect that the key parameters of the suction cup system have on the suction characteristic is analyzed and the conclusions are presented.

Online Trajectory Generation Based on Off-line Trajectory for Biped Humanoid

This paper proposed a method of online trajectory generation based on key parameters of off-line trajectories for a biped humanoid. The key parameters include hip parameters, step length, walking cycle and so on. The walk pattern can be obtained according to these parameters. In order to generate walk patterns online, first key parameters of the on-line walk pattern are computed based on the off-line parameters, and then the on-line trajectories are derived. The effectiveness of this method is confirmed by simulations and experiments with our developed humanoid robot BHR-01

Location and Tracking of Robot End-effector Based on Stereo Vision

In this paper stereo vision based tracking system for humanoid robot is proposed. The goal is to locate and track the end-effector in unknown and dynamic environments. A robust approach is developed by utilizing visual features. Identical visual features such as color, disparity and adaptive template matching are used to detect and track the end-effector robustly. An improved active search method is used in order to realize effective tracking of end-effector. Active search stereo vision system of humanoid robot is designed. Two computers are embedded in to the system to realize real time robust tracking of end-effector. One computer is used for processing visual information and other one is responsible for servo control of pan-tilt platform on which CCD cameras are mounted. The performance of the developed modular visual cues based tracking of end-effector is exploited through experiments.

A floor cleaning robot using Swedish wheels

This paper presents a floor cleaning robot equipped with Swedish wheels. It can be used in crowded places such as houses, train station, airport etc. the robot can perform its work in autonomous and teleoperated mode. Moreover the robot can pivot around without turning, can avoid obstacles and is provided with automatic power management ability. And meanwhile, the kinematics for its control and controlling methods are studied and demonstrated. This new structure, smooth locomotion capability and high working efficiency are verified by experimentation.

Humanoid kinematics mapping and similarity evaluation based on human motion capture

The captured data must be adapted for the humanoid because its kinematics and dynamic differ from those of the human actor. The kinematics constraints such as ground contact conditions are crucial for humanoid locomotion. Furthermore, it is desirable that the humanoid motion have of high similarity with those of the human actor. In this paper, first the similarity function of the humanoid motion is proposed. Then, the kinematics constrains including ground contact conditions are formulated, and the algorithm to derive the humanoid motion with a high similarity and satisfying kinematics constraints is present. Finally, the effectiveness is confirmed by the experiment of Chinese Kongfu Taiji using our developed 33 DOF humanoid robot.

Research of the frequency calibration of high shock accelerometer using Hopkinson bar

A method about the shock comparison frequency calibration is brought forward in this paper to calibrate a high shock accelerometer using the Hopkinson bar as the pulse exciter. The output of the standard accelerometer is used as the input of the test accelerometer, the output of the test accelerometer is used as the output of test accelerometer, the transfer function can be obtained by the characteristic of the input and the output of the test accelerometer, then the frequency characteristic of the test accelerometer is known.

Stability adjustment of dynamic motion considering similarity based on human motion capture

The captured human data cant be used to drive the humanoid robot directly because of different bodys configurations and physical properties between the humanoid robot and the human actor, and it must be adapted through stability adjustment. The stability is a fundamental condition for humanoid motion. A method of stability adjustment considering high similarity with the human actor is proposed in this paper. The effectiveness of the method is confirmed by simulations and experiments of Chinese Kungfu Daoshu using our developed 32 DOF humanoid robot

Towards automated micromachining of PMMA micro channels using CO/sub 2/ laser and sacrificial mask process

A novel system for 3D microchannel fabrication based on CO/sub 2/ laser-micromachining is presented. The system consists of a CO/sub 2/ laser focusing system and a 3D precision positioning platform. The CO/sub 2/ laser focusing system can regulate a laser beam which is of appropriate energy level and of micron dimension in beam diameter. The fabrication of 3D microchannel system in PMMA (polymethyl methacrylate) can be realized by controlling the CO/sub 2/ laser and a 3-axis platform with micron-resolution movement. A special sacrificial mask process was used to produce translucent channels of micron dimensions with low surface roughness using the developed system. The effectiveness of our developed system is confirmed by experimental results. Potentially, our developed system can be automated to produce 3D micro channels in PMMA substrates without the requirement for the costly and time-consuming lithography and hot-embossing processes that are needed currently.

Micro channel fabrication in PMMA substrates using CO/sub 2/ laser and sacrificial mask process

A novel system for 3D microchannel fabrication based on CO/sub 2/ laser-micromachining is presented. The system consists of a CO/sub 2/, laser focusing system and a 3D precision positioning platform. The CO/sub 2/ laser focusing system can regulate a laser beam which is of high-energy and of micron dimension in beam diameter, and the movement precision of the 3D platform is of micron dimension. The fabrication of 3D microchannel system in PMMA (polymethyl methacrylate) can be realized by controlling the CO/sub 2/ laser and the platform. A special sacrificial mask process was used to produce translucent channels of micron dimensions with low surface roughness using the developed system. The effectiveness of our developed system is confirmed by the experimental results. Potentially, our developed system can be automated to produce 3D micro channels in PMMA substrates without the requirement for the costly and time-consuming lithography and hot-embossing processes that are needed currently.