无人机系统常采用脉冲宽度调制信号(PWM)控制舵机执行机构,在进行飞行控制系统闭环半物理仿真中,需要实时采集舵机控制信号作为无人机模型的控制输入,进而构成闭环仿真。提出并实现了一种以FPGA为核心的PWM信号转换器的设计,给出了PWM信号转换器各部分模块的详细设计,并用Verilog在FPGA中实现了其全部功能。在对FPGA设计的PWM信号转换器模块功能仿真和时序仿真正确后,下载到Altera开发板中进行验证。测试结果表明,利用FPGA设计的PWM信号转换器模块具有测量精度高、简单高效的特点,满足了实时仿真的要求。
PWM(pulse width modulation) signal is often adapted by UAV(unmanned aerial vehicle)to control actuators.In the flight control system HIL(hardware in the loop) simulation,the simulation models need to measure the PWM signal to construct the simulation loop.The PWM signal converter based on FPGA(field programmable gate array) is designed in detail.All the modules of PWM signal converter are studied and implemented in Verilog language.The design is verified in Altera development board after the correct function and timing simulation.The experimental results demonstrate that the PWM signal converter based on FPGA has some advantages,such as high precision,high efficiency and so on.The PWM signal converter model meets the need of the flight control system HIL simulation and has certain application value.