| The frequency of forest fire is a great threat to forest ecology and the development of national economy. Complex and changeable forest terrain environment blocks the entry of fire-fighting and rescue equipment, and it is dangerous for those who detect or clean forest fire embers. Based on the status of domestic forest fires and relevant embers detection and cleaning technologies and methods, and concerning that hexapod bionic robot has good motion performance, the mechanism for forest fire embers detection robot is designed and its control system is built, so that it can be used for detecting and cleaning forest fire embers.(1)According to the research of six-legged insects body structures and the features of international and domestic multi-legged bionic robot structure design, motion platform and implementing mechanism for forest fire embers detection robot is designed with the help of Solid Works—a three-dimensional software. The motion platform consists of six legs and contains 18 degrees of freedom which mainly come from legs, bodies and driving devices. The implementing mechanism has 4 degrees of freedom which mainly come from base, upper arm, elbow, forearm, drive motor, etc. Besides, other work such as selecting motors, reducers, controllers and installing sensors has been done as well.(2)For convenience of path planning and motion control of forest fire embers detection robot, kinematics analysis is done to the hexapod robot. The end position coordinate of each leg is discussed in detail. Through D-H method, build a coordinate system to describe the motion of legs and implementing mechanism. Calculate the end positions of legs and implementing mechanism according to joint angles by using kinematic equation. By using inverse kinematic equation, calculate joint angles based on known coordinates so as to lay a good foundation for robot excellent performance.(3)Using ADAMS to carry on kinematics simulation for designed robot model. Through robot crawling experiments on flat and rugged slopes, derive angular velocity and suffered moment of robot centroid displacement, base leg joints, hip joints and knee joints. Simulation curves show that the robot has great stability when crawl on flat and rugged slopes, which verify the rationality and correctness of robot platform design. Through implementing mechanism motion stimulation analysis, derive the displacement of end actuator and torque curves of base joint, wrist joint and elbow joint on implementing mechanism, which demonstrate that implementing mechanism has the ability of cleaning obstacles and can provide support for cleaning work during motion process.(4)According to the complex and changeable working environment and working demands, robot motion control together with forest fire embers detection control system are promoted. The control system design is based on the numbers of degrees of freedom in platform and implementing mechanism, sensor information conveying, forest fire embers detection, forest terrain adaption and obstacles cleaning. Robot control system consists of central control system, sensor modules, motion control module, driving and execution module, embers information detection. The controller, inertial navigation system, power supply battery and DC servo drives, smoke, temperature, flame sensors are properly selected. Software architecture of robot control system is designed and automatic and manual control mode is proposed so as to lay a solid theoretical foundation for the precise control of the robot in the future. |
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