stm32 怎么用pid控制步进电机速度
时间: 2024-03-22 09:30:18 浏览: 11
使用PID控制步进电机速度需要以下几个步骤:
1. 设置定时器:使用定时器产生固定的时间间隔,用于计算PID控制器的输出值。
2. 读取编码器反馈信号:使用编码器读取电机的实际旋转速度。
3. 计算误差:将期望速度与实际速度相减,得到误差值。
4. 计算PID输出:将误差值代入PID控制器中,计算出PID输出值。
5. 更新PWM占空比:将PID输出值转换为PWM占空比,用于控制步进电机的速度。
以下是一个简单的示例代码,供参考:
```c
#include "stm32f4xx.h"
// 编码器反馈信号引脚
#define ENCODER_PIN GPIO_Pin_0
#define ENCODER_PORT GPIOA
// 步进电机控制信号引脚
#define MOTOR_PIN GPIO_Pin_1
#define MOTOR_PORT GPIOA
// PID控制器参数
float Kp = 1.0;
float Ki = 0.0;
float Kd = 0.0;
float set_speed = 100.0; // 期望速度
float actual_speed = 0.0; // 实际速度
float error = 0.0; // 误差值
float integral = 0.0; // 积分值
float derivative = 0.0; // 微分值
float last_error = 0.0; // 上一次误差值
// 定时器中断服务函数
void TIM3_IRQHandler(void)
{
if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)
{
// 读取编码器反馈信号,计算实际速度
actual_speed = ...;
// 计算误差
error = set_speed - actual_speed;
// 计算积分值
integral += error;
// 计算微分值
derivative = error - last_error;
last_error = error;
// 计算PID输出值
float pid_output = Kp * error + Ki * integral + Kd * derivative;
// 更新PWM占空比
TIM_SetCompare1(TIM2, pid_output);
TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
}
}
int main(void)
{
// 初始化GPIO
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
// 步进电机控制信号引脚
GPIO_InitStructure.GPIO_Pin = MOTOR_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(MOTOR_PORT, &GPIO_InitStructure);
GPIO_PinAFConfig(MOTOR_PORT, GPIO_PinSource1, GPIO_AF_TIM2);
// 编码器反馈信号引脚
GPIO_InitStructure.GPIO_Pin = ENCODER_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(ENCODER_PORT, &GPIO_InitStructure);
// 初始化定时器2,用于产生PWM信号
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
TIM_TimeBaseStructure.TIM_Period = 999;
TIM_TimeBaseStructure.TIM_Prescaler = 839;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM2, &TIM_OCInitStructure);
TIM_Cmd(TIM2, ENABLE);
// 初始化定时器3,用于控制PID计算的时间间隔
NVIC_InitTypeDef NVIC_InitStructure;
TIM_TimeBaseStructure.TIM_Period = 999;
TIM_TimeBaseStructure.TIM_Prescaler = 839;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);
TIM_Cmd(TIM3, ENABLE);
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
while (1)
{
// 设置期望速度
set_speed = ...;
}
}
```
注意,以上代码仅为示例代码,需要根据实际情况进行修改和适配。