Chi-Tai Cheng

Fuzzy Control of Humanoid Robot for Obstacle Avoidance

A fuzzy system based on the obtained information of four infrared (IR) sensors and one electronic compass is proposed and implemented on a humanoid robot to avoid obstacles. A humanoid robot named TWNHR-3 with 26 degrees of freedom (DOFs) is designed so that it can do five basic motions. Four IR sensors and one electronic compass are installed on TWNHR-3 to detect the environment information including obstacles, the distances of the obstacles, and the directional angle of the robot. Based on the obtained information, an obstacle avoidance method is proposed to decide one behavior from five motions so that it can avoid obstacles and go to the destination area effectively. Some MATLAB simulation results with different number of obstacles and two real experiments are presented to illustrate the effectiveness of the proposed method.

Static balancing control of humanoid robot based on accelerometer

A static balancing control method is proposed and implemented on a humanoid robot so that the robot can stand and balance on a plane. A small-size humanoid robot named TWNHR-IV with 26 degree-of-freedom (DOF) is implemented. A 3-axis accelerometer is installed on TWNHR-IV to obtain the x-axis, y-axis, and z-axis accelerations of TWNHR-IV. Based on the obtained information from the 3-axis accelerometer, a system structure with two two-input-and-one-output fuzzy systems is proposed. The acceleration and the accelerationpsilas variation of the x-axis obtained by the 3-axis accelerometer are considered to be the inputs of forward-and-backward fuzzy system. The acceleration and the accelerationpsilas variation of the y-axis are considered to be the inputs of right-and-left fuzzy system. Some practical tests are presented to illustrate the proposed method can let the humanoid robot stand and balance on a plane.

Fuzzy Balancing Control of a Small-size Humanoid Robot based on Accelerometer

A fuzzy balancing control method is proposed and implemented on a small-size humanoid robot named TWNHR-IV in this paper. The robot TWNHR-IV is able to stand and balance on an inclined plane by the proposed method. A 3-axis accelerometer is mounted on the robot TWNHR-IV, which has 26 degrees-of-freedom (DOFs), for obtaining the 3-axis accelerations of TWNHR-IV. The proposed fuzzy method includes two two-input-and-one-output fuzzy systems, the forward-and-backward fuzzy system and the right-and-left fuzzy system. Based on the obtained information from the 3-axis accelerometer, the proposed method is able to modify the feet posture to balance TWNHR-IV. Some practical experiments with different inclining situations are presented to illustrate the efficiency of the proposed fuzzy balancing control method.

Design and Implementation of an Autonomous Robot Soccer System

Abstract A design and implementation method of a robot soccer system with three vision-based autonomous robots is proposed in this paper. A hierarchical architecture with four independent layers: (a) information layer, (b) strategy layer, (c) tactics layer, and (d) execution layer, is proposed to construct a flexible and robust vision-based autonomous robot soccer system efficiently. Five mechanisms, including (a) a two-dimensional neck mechanism, (b) dribbling mechanism, (c) shooting mechanism, (d) aiming mechanism, and (e) flexible movement mechanism, are proposed to mean the robot with multiple functions can win the game. A method based on data obtained from a compass and a vision sensor is proposed to determine the location of the robot on the field. In the strategy design, a hierarchical architecture of decision based on the finite-state transition mechanism for the field players and the goalkeeper is proposed to solve varied situations in the robot soccer game. Three vision-based robots are implemented and some real competition results in the FIRA Cup are presented to illustrate the validity and feasibility of the proposed method in autonomous robot soccer system design.

CORDIC-based FPGA hardware design method for biped walking gait

In this paper, a simple oscillator-based biped walking method is described and a CORDIC-based FPGA hardware design method is proposed to effectively generate a walking gait in a biped robot. Based on the simple oscillator-based model, some equations represented by sinusoidal functions are proposed to describe a biped walking as a complete walking process with three modes (starting mode, gait cycle mode, and ending mode) and six phases. In these six phases, these oscillation parameters can be represented by the swing length, the step length, and the lifting height of the biped robot. Then an FPGA hardware structure based on the CORDIC operator named circular rotation is proposed and implemented on an FPGA chip. Finally, some comparison of the proposed CORDIC-based FPGA hardware method and the software method are presented. We can see that the proposed hardware method significantly reduces the processing time to generate gait trajectories of a biped robot.

Motion and Emotional Behavior Design for Pet Robot Dog

A pet robot dog with two ears, one mouth, one facial expression plane, and one vision system is designed and implemented so that it can do some emotional behaviors. Three processors (Inter® Pentium® M 1.0 GHz, an 8-bit processer 8051, and embedded soft-core processer NIOS) are used to control the robot. One camera, one power detector, four touch sensors, and one temperature detector are used to obtain the information of the environment. The designed robot with 20 DOF (degrees of freedom) is able to accomplish the walking motion. A behavior system is built on the implemented pet robot so that it is able to choose a suitable behavior for different environmental situation. From the practical test, we can see that the implemented pet robot dog can do some emotional interaction with the human.

Vision-based localization system for XY tracking platform

A vision-based localization system for XY Tracking platform is proposed in this paper. This platform is designed for assisting the humanoid robot to measure the walking performance. When the humanoid robot walks, the platform will keep tracking the robot and localize the position. The proposed system is able to overcome the image block problem, which is caused by the humanoid robots moving. Two cameras are mounted on the XY platform to analyze the robots position and the platforms position. Five color models including Red, Yellow, Green, Blue, and Purple are used for building the landmark. Each landmark is a combination of two or three colors. The platform labels the landmark by a series of the image processing procedure. After the platform labels the landmarks, the platform calculates the relationship between the landmark and the platform to localize itself. The experiment illustrates the effectiveness of the proposed system.

One-leg lifting method for humanoid robots based on SOPC design

An one-leg lifting method for the humanoid robot based on SOPC design is proposed in this paper. Four pressure sensors are mounted on each foot for calculating the center of the robots mass. In order to speed up the calculating time, the purposed method is implemented on a System On a Programmable Chip (SOPC). The proposed method uses the determined value of the center of the mass to adjust the rotation of the robots joint. During the robot is lifting its leg, the center of the mass will be keep inside of the support foot. The practical experiment illustrates the effectiveness of the proposed system.

Fuzzy Basketball Throwing Strength Control System for Vision-Based Humanoid Robot

A fuzzy basketball throwing strength control system for vision-based humanoid robot is proposed in this paper. The implemented method is able to adjust the speed of throwing ball for joining the basketball event in HuroCup (Humanoid Robot World Cup Soccer Tournament). The proposed method speeds up the aiming time and increases the shooting accuracy. A two inputs and one output fuzzy system are designed in this paper. Two inputs, the distance and the voltage, are used for the implemented method. The robot detects the distance between the robot and basket based on the robot’s vision system. An analog to digital system is applied to measure the robot’s voltage, which changes the torque of the motor. The output value of the fuzzy system is the motor speed of the shoulder. The proposed fuzzy system is able to decide the motor speed of the shoulder to throw the table tennis ball, which is substituted for the basketball. The effectiveness of the system is demonstrated in an empirical evaluation.

Design and Implementation of Omni-directional Walking System for Humanoid Robot

An omni-direction walking system for humanoid robot is presented in this paper. This method combines a mark time motion and a walking trajectory planning system. Three sub-motions, including leg shifting, leg lifting and leg opening, with same frequency are proposed to accomplish the mark time motion. The proposed omni-directional walking system is established to make robot walk fast in the soccer field.