Obstacle-Avoiding Sensoring Unit Development And Trajectory Regulating Research Of Home Security Robot

Currently service robot which sells at a high price serves mainly in the hotel and museum and has only a very small consumption market. Therefore, it has a very wide market to exploit home service robots with lower cost, lower power dissipation, lower volume, higher reliability and higher intelligent level.This paper adopts hardware system based on 32-bit ARM processor S3C44B0X made by Samsung Corporation as the control kernel of the security robot, other than traditional computer control system. It makes full advantage of embed system's high performance, plenty of interfaces, easy extending, rich of recourses and so on. It solves the disadvantage of programming exploiting and maintaining with the system getting bigger and bigger by transplanting real time operation systemμC/OS-II, GUI graph supporting system, increasing the ability of system operating and fulfill the communication of multi-task.This paper develops cost-effective obstacle avoiding sensor unit. It utilizes 8 bit microprocessor AT89C52 to realize control of the unit and data collecting and processing. It detects the obstacle distance in the environment by controlling the eight ultrasonic sensors at different time. Infrared sensor makes up for the dead zone shortcoming of ultrasonic sensors. In terms of requirements of robot's displacement and attitude precision, this paper designs a motor driving module based on high precise motion control and all-digital position-serving control IC LM629 and exclusive DC motor driving IC LMD18200. Motor driving unit, motor and incremental coder composes a complete close-loop feed-back system. And the paper gives the kinetic mathematical model of the robot movement. It uses the data fed back by the coder to figure out the robot's displacement and attitude in the global coordinate and plans the local track according to the local environment information which is given by the sensor unit and processed by the simplified artificial potential field method to let the robot duck obstacles while moving forward to the destination point.The paper makes experiments on the home security robot platform. It verifies the validity of motor control and robot displacement and attitude calculation to control the robot through remote controller. And it also certifies accuracy of robot response and real time ability of communication control to communicate with the speech recognition module, intelligent charging module and computer via extended five R232 interfaces. The experiment results improve the feasibility of the embedded system which apples on the home security robot. The embedded system also has the advantage of lower cost, high real time ability and plenty of functions.