HAL STM32F1 通过查表方式实现SVPWM驱动无刷电机测试
- 📍相关篇《基于开源项目HAL STM32F4 +DSP库跑SVPWM开环速度测试》
- ✨针对STM32F1系列，硬件上没有可用的浮点单元（FPU），为了实现特定函数的浮点运算快速计算，通过查表方式来实现，以空间换速度的方式。
- 📍硬件电路和项目参考，立创开源广场：
https://oshwhub.com/shadow27/tai-yang-neng-wu-ren-chuan - 📌 采用6路驱动控制，可以参考个人的相关篇《自制无感无刷电机驱动板》
📘实现核心代码
- 📑
svpwm.c
#include "tim.h"
#include "svpwm.h"
#include "stdio.h"
#define PWM_Period 4800
float voltage_power_supply=12; //母线电压12V
float sensor_offset=0;
float zero_electric_angle=0;
float _normalizeAngle(float angle)// 标准化角度 [0,2PI]
{
float a = fmod(angle, _2PI); //fmod()对浮点数取模
return a >= 0 ? a : (a + _2PI);
}
//把0~Π/2的正弦值分成200份
const int sine_array[200] = {0,79,158,237,316,395,473,552,631,710,789,867,946,1024,1103,1181,1260,1338,1416,1494,
1572,1650,1728,1806,1883,1961,2038,2115,2192,2269,2346,2423,2499,2575,2652,2728,2804,2879,2955,3030,
3105,3180,3255,3329,3404,3478,3552,3625,3699,3772,3845,3918,3990,4063,4135,4206,4278,4349,4420,4491,
4561,4631,4701,4770,4840,4909,4977,5046,5113,5181,5249,5316,5382,5449,5515,5580,5646,5711,5775,5839,
5903,5967,6030,6093,6155,6217,6279,6340,6401,6461,6521,6581,6640,6699,6758,6815,6873,6930,6987,7043,
7099,7154,7209,7264,7318,7371,7424,7477,7529,7581,7632,7683,7733,7783,7832,7881,7930,7977,8025,8072,
8118,8164,8209,8254,8298,8342,8385,8428,8470,8512,8553,8594,8634,8673,8712,8751,8789,8826,8863,8899,
8935,8970,9005,9039,9072,9105,9138,9169,9201,9231,9261,9291,9320,9348,9376,9403,9429,9455,9481,9506,
9530,9554,9577,9599,9621,9642,9663,9683,9702,9721,9739,9757,9774,9790,9806,9821,9836,9850,9863,9876,
9888,9899,9910,9920,9930,9939,9947,9955,9962,9969,9975,9980,9985,9989,9992,9995,9997,9999,10000,10000};
//0~360°的正弦值，函数通过使用固定大小的数组来逼近正弦计算
float _sin(float a){//a的值最大为2Π，即6.28318530718
if(a < _PI_2){//a<1.57079632679
//return sine_array[(int)(199.0*( a / (_PI/2.0)))];
//return sine_array[(int)(126.6873* a)]; // 浮点数组优化
return 0.0001*sine_array[_round(126.6873* a)]; // int数组优化
}else if(a < _PI){//1.57079632679<=a<3.14159265359
// return sine_array[(int)(199.0*(1.0 - (a-_PI/2.0) / (_PI/2.0)))];
//return sine_array[398 - (int)(126.6873*a)]; // float array optimized
return 0.0001*sine_array[398 - _round(126.6873*a)]; // int array optimized
}else if(a < _3PI_2){//3.14159265359<=a<4.71238898038
// return -sine_array[(int)(199.0*((a - _PI) / (_PI/2.0)))];
//return -sine_array[-398 + (int)(126.6873*a)]; // float array optimized
return -0.0001*sine_array[-398 + _round(126.6873*a)]; // int array optimized
} else {//4.71238898038<=a<6.28318530718
// return -sine_array[(int)(199.0*(1.0 - (a - 3*_PI/2) / (_PI/2.0)))];
//return -sine_array[796 - (int)(126.6873*a)]; // float array optimized
return -0.0001*sine_array[796 - _round(126.6873*a)]; // int array optimized
}
}
//0~360°的余弦值，函数逼近余弦计算使用固定大小的数组
float _cos(float a){
float a_sin = a + _PI_2;
a_sin = a_sin > _2PI ? a_sin - _2PI : a_sin;
return _sin(a_sin);
}
//近似开根号函数
float _sqrtApprox(float number) {//low in fat
long i;
float y;
// float x;
// const float f = 1.5F; // better precision
// x = number * 0.5F;
y = number;
i = * ( long * ) &y;
i = 0x5f375a86 - ( i >> 1 );
y = * ( float * ) &i;
// y = y * ( f - ( x * y * y ) ); // better precision
return number * y;
}
// 输入参数0.0f ~ 1.0f，输出3路PWM
//void Set_PWM(float _CCR1, float _CCR2, float _CCR3)
//{
// __HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, _CCR1 * PWM_ARR);
// __HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_2, _CCR2 * PWM_ARR);
// __HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_3, _CCR3 * PWM_ARR);
//}
//FOC核心函数：输入Ud、Uq和电角度，输出PWM
void setPhaseVoltage(float Uq, float Ud, float angle_el)
{
float Uref;
uint32_t sector;
float T0,T1,T2;
float Ta,Tb,Tc;
float U_alpha,U_beta;
angle_el =_normalizeAngle(angle_el); //电角度标准化在【0,2pi】
U_alpha=Ud*_cos(angle_el)-Uq*_sin(angle_el); //反park变换
U_beta=Ud*_sin(angle_el)+Uq*_cos(angle_el);
Uref=_sqrtApprox(U_alpha*U_alpha + U_beta*U_beta) / voltage_power_supply;
if(Uref> 0.577)Uref= 0.577; //六边形的内切圆(SVPWM最大不失真旋转电压矢量赋值)根号3/3
if(Uref<-0.577)Uref=-0.577;
if(Uq>0)
angle_el =_normalizeAngle(angle_el+_PI_2); //加90度后是参考电压矢量的位置
else
angle_el =_normalizeAngle(angle_el-_PI_2);
sector = (angle_el / _PI_3) + 1; //扇区判断
//每个扇区中两个相邻电压矢量Uref作用时间
T1 = _SQRT3*sin(sector*_PI_3 - angle_el) * Uref;
T2 = _SQRT3*sin(angle_el - (sector-1.0)*_PI_3) * Uref;
//零矢量作用时间
T0 = 1 - T1 - T2;
switch(sector) //计算各相的作用时间
{
case 1:
Ta = T1 + T2 + T0/2;
Tb = T2 + T0/2;
Tc = T0/2;
break;
case 2:
Ta = T1 + T0/2;
Tb = T1 + T2 + T0/2;
Tc = T0/2;
break;
case 3:
Ta = T0/2;
Tb = T1 + T2 + T0/2;
Tc = T2 + T0/2;
break;
case 4:
Ta = T0/2;
Tb = T1+ T0/2;
Tc = T1 + T2 + T0/2;
break;
case 5:
Ta = T2 + T0/2;
Tb = T0/2;
Tc = T1 + T2 + T0/2;
break;
case 6:
Ta = T1 + T2 + T0/2;
Tb = T0/2;
Tc = T1 + T0/2;
break;
default: //其他情况关闭上管，打开下管，即刹车
Ta = 0;
Tb = 0;
Tc = 0;
}
//printf("[Ta,Tb,Tc]:%f,%f,%f\r\n", Ta, Tb, Tc);
__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, Ta*PWM_Period); //输出U相PWM,配置占空比
__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_2,Tb*PWM_Period); //输出V相PWM,配置占空比
__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_3, Tc*PWM_Period); //输出W相PWM,配置占空比
}
- 📄
svpwm.h
#ifndef __SVPWM_H__
#define __SVPWM_H__
#include <math.h>
#define _sign(a) ( ( (a) < 0 ) ? -1 : ( (a) > 0 ) )
#define _round(x) ((x)>=0?(long)((x)+0.5):(long)((x)-0.5))
#define _constrain(amt,low,high) ((amt)<(low)?(low):((amt)>(high)?(high):(amt)))
#define _sqrt(a) (_sqrtApprox(a))
#define _isset(a) ( (a) != (NOT_SET) )
#define _2_SQRT3 1.15470053838
#define _SQRT3 1.73205080757
#define _1_SQRT3 0.57735026919
#define _SQRT3_2 0.86602540378
#define _SQRT2 1.41421356237
#define _120_D2R 2.09439510239
#define _PI 3.14159265359
#define _PI_2 1.57079632679
#define _PI_3 1.0471975512
#define _2PI 6.28318530718
#define _3PI_2 4.71238898038
#define _PI_6 0.52359877559
//FOC核心函数：输入Ud、Uq和电角度，输出PWM
void setPhaseVoltage(float Uq, float Ud, float angle_el);
#endif /* __SVPWM_H__ */
- 🌿在滴答回调函数中，每隔2毫秒执行一次
void HAL_SYSTICK_Callback(void)
{
// Sys_Tick_Count_1ms();
Count++;
if (Count >= vtaskms)
{
Count = 0;
//Uq和电角度增加值需要自己调，每个电机都不一样
setPhaseVoltage(0.5,0.0,angle_el); //空载的时候尽量让uq<2。Uq越大电机的电流越大，扭力约大
angle_el +=0.64; //估计电角度，电角度增加的越快，电机转的越快。电角度减小则电机反向旋转0.18 0.36 0.54 0.62
}
}
🎉在电机能转动的情况下，可以逐步增大电角度（
angle_el）数值，以提高转动的速度。在电机能提速的情况下，电流相对会减少。这个速度也不是不限增加的，当程序设定的角度电机执行完，正好与下一次循环设定的角度接近重合时，达到最佳的运转效果。
个人使用2204电机测试，在电角度参数和电机运转步进接近的状态下，空载下运转，电流只有60毫安左右，长时间运转，电机都没有感受发热。
-
🌿3路PWM驱动波形及参数
-
🌿三相驱动桥，下端电流采样波形
📚测试工程
- 🌿基于3路PWM控制。（EG2133）
链接：https://pan.baidu.com/s/1H_5o-4v7Z8x4XBi8RtVU1A?pwd=rcv6
提取码：rcv6
- 🌿基于3路互补PWM输出控制。
链接：https://pan.baidu.com/s/13mFTlaAbvnjr1eh-rdLQSQ?pwd=2fr7
提取码：2fr7
