Development of Primitive Circuit in a Scalable and Flexible PWM Mechanism Using FPGA

Abstract

Servomotors are used in various applications such as joints of industrial robots, joints of humanoid robots, and belt mechanisms of conveying equipment. To realize better articulated robots, more complex and high-performance motions using many servomotors will be required in the future. To use many servomotors, many microcontrollers controlling them are required. This approach may increase the scale of the system. This fact will lead to an increase in cost and largen the difficulty to control and manage many servomotors. To solve these problems, we aim to realize a scalable and flexible PWM mechanism using a general-purpose dynamic partial reconfiguration microcontroller that can dynamically reconfigure the circuit. Dynamic Partial Reconfiguration can be applied to control many servo motors with a single platform. Since this is a single platform running, the number of hardware can be physically reduced, which greatly reduces the cost. In addition, it can be expected to save power because only one part of the system operates at a time. The goal of this research is to develop a circuit that generates PWM, which is constructed by dynamic partial reconfiguration. In our experiments, we compare the conventional PWM generation circuit with the servomotor-specific circuit and examine the differences in circuit size and performance. The experiments showed that the proposed system, which specifies only the numerical value of the angle, can be executed in a shorter time than the conventional system, in which the period and pulse width of the servomotor to be used are specified from the CPU to run the PWM generation circuit.