Application And Development Of FPGA In Embedded Controller For Painting Robot

Spraying is a painting method which is the most widely used in many industry nowdays.As more and more industries request higher spray quality,efficiency,complexity and diversity.Traditional manual spraying and automatic spraying has been unable to meet the needs.The development of computer numeric control makes the robot spraying become a trend in spraying operations nowdays.Technology of robot spraying is relatively mature in foreign,and has already begun to study it at 1960 s.Now the market for painting robot is still dominated by foreign companie’s robot brand,such as Germany’s KUKA,Sweden’s ABB,Japan’s FANUC and MOTOMAN.Interiorly,we start late in the research on the spray robot,and lag in the correlative technology compared with foreign countries,and now the domestic manufacturers have little ability to produce the painting robot independently.According to the domestic market demand for painting robot,the development on technical level of robot,and the workers’ s current level of robot operating,we can take foreign countrys as lessons.In this project,a embedded controller for painting robot by direct teaching based on heterogeneous dual-core processor OMAPL138 + FPGA is proposed to solve the problem of the inertial load and damping force of every joint in robotic teaching by servo torque control.According to the function planning of the embedded controller for painting robot by direct teaching and the application of FPGA in controller,this paper study the overall scheme of the controller,the construction of software platform,the hardware circuit design and the controlling software design for device based on FPGA.According to the functional requirements and design objectives of the robot controller,the controller is divided into three levels: interface layer,control layer and equipment layer.The ARM core of the OMAPL138 is responsible for communication with the robot interface and system management.The DSP core is responsible for robot coordinate transformation,joint interpolation,sampling information processing and power-assist algorithm.The FPGA is responsible for the control and detection of the robot equipment.And this paper analyzes the overall scheme of the controller based on OMAPL138 + FPGA,and designs the controller hardware and software platform.Combined with the layout and power designing of the controller for painting robot based on OMAPL138 + FPGA,it introduced the hardware resources of OMAPL138 core board are,and focused on the circuit design of FPGA expansion board and terminal board.And according to the communication interface between OMAPL138 and FPGA,analyzes the hardware circuit of EMIFA bus,designs the communication by EMIFA between FPGA and OMAPL138.According to the signal sampling,position/torque control and switching of servo,and detection and control of I/O device,it studied the design and implementation of the controller software for painting robot based on FPGA,including the module of incremental pulse sampling,DAC controller,the module of digital/pulse conversion and I/O monitoring,this provide the underlying support for achieving the spraying-teach,power-assist and reproduction of the painting robot.Finally,it performs the functional test of the controller for painting robot,verify whether the controller can realize the robot’s teaching and reproducing function and achieve the desired spraying effect by the painting test for workpiece with painting robot.At present,after the verification of the controller’s function,it has been used in a painting robot system of the company in Foshan.