#include "PID.h" #include "Relays.h" #include "USART.h" #include "rs485.h" float cold_tem = 0; float red_tem = 0; float ti; float ki = 0.001; float kd = 340; extern u8 hot_clod_flag; extern u8 gpio_state; extern int T; unsigned int num = 0; PID pid; int min_speed_count = 2000; int max_speed_count = 4800; /** * PID init */ void PID_Init() { // // if flash have not a vaild value, just set a default value // if (pid.Kp < 1e-7) { pid.Kp = 9.6; } // if (pid.Ki < 1e-7) { pid.Ki = 0.01; } // if (pid.Kd < 1e-7) { pid.Kd = 340; } // if (pid.tem_threshold < 0.0001) { pid.tem_threshold = 0.2; } pid.Ek = 0; pid.Ek_prev = 0; pid.SEk = 0; pid.Pout = 0; pid.Iout = 0; pid.Dout = 0; pid.OUT = 0; pid.OUT0 = 0; pid.h_percent = 0; pid.c_speed = 0; pid.t = 1000; // PID calc period // pid.Ti=5000000;// integral time // pid.Td=1000;// differential time pid.pwmcycle = 200; // pwm cycle 200 pid.OUT0 = 1; pid.C1ms = 0; pid.max_compressor_tem = 30; pid.hp_h = 5; pid.hi_h = 0.02; pid.hd_h = 0.5; pid.h_base_h = 0; pid.hp_l = 19.2; pid.hi_l = 0.08; pid.hd_l = 0; pid.h_base_l = 53; pid.cp = 9.6; pid.ci = 0; pid.cd = 0; pid.c_base = 37; } /** * set compressor speed count * range of speed count: 0-6000, if speed count lower than 1500, the compressor will stop */ void set_compressor_power(int speed) { u8 data[8] = {0x01, 0x06, 0x60, 0x00, 0x00, 0x09, 0xBB, 0xAA}; // speed control for compressor controller if (speed > max_speed_count) { speed = max_speed_count; } if (speed < 0) { speed = 0; } data[4] = speed / 256; data[5] = speed % 256; GetCRC16(data, 6, data + 6, data + 7); RS485_3_Init(9600); delay_xms(30); RS485_3_Send_Data(data, 8); delay_xms(30); RS485_1_Init(9600); } /** * set heater percent * range of heater percent: 0-100 */ void set_heater_power(int percent) { u8 data[8] = { 0x10, 0x06, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00 }; if (percent > 100) { percent = 100; } if (percent < 0) { percent = 0; } data[4] = percent / 256; data[5] = percent % 256; GetCRC16(data, 6, data + 6, data + 7); RS485_1_Init(9600); delay_xms(30); RS485_1_Send_Data(data, 8); delay_xms(30); } /** * heater power calc */ int calc_hp(float delta_t, float Error_calc, float DelEk, int p_hb, float pid_hp, float pid_hi, float pid_hd) { int p_h = p_hb + pid_hp * delta_t + pid_hi * Error_calc + pid_hd * DelEk; if (p_h > 100) { return 100; } if (p_h < 0) { return 0; } return p_h; } /** * compressor power percent calc */ int calc_cp(float delta_t, int p_cb, float pid_cp) { int percent = p_cb - pid_cp * delta_t; if (percent > 100) { return 100; } if (percent < 0) { return 0; } return percent; } /** * compressor speed calc */ int calc_compressor_speed(int percent, int v_min, int v_max) { int v = percent * v_max / 100.0; if (v > v_max) { return v_max; } if (v < v_min) { return v_min; } return v; } void PID_Calc() // pid calc { // int min_speed_count = 1800; // int max_speed_count = 4800; float DelEk; // The difference between the last two deviations // float td; float out; // if (pid.C1ms < (pid.t)) // The calculation cycle has not yet arrived // { // return; // } float delta_t = pid.set_tem - pid.now_tem; // When the target tem is greater then max compressor tem, the compressor will stop if (pid.set_tem > pid.max_compressor_tem) { pid.c_speed = 0; } else { int p_c = calc_cp(delta_t, pid.c_base, pid.cp); pid.c_speed = calc_compressor_speed(p_c, min_speed_count, max_speed_count); } float hp = pid.hp_h; float hi = pid.hi_h; float hd = pid.hd_h; int h_base = pid.h_base_h; // if now temp is close to set temp, the heater will be less power if (pid.set_tem - pid.now_tem < 3) { hp = pid.hp_h * 0.6; } // l mode if (pid.set_tem <= pid.max_compressor_tem) { hp = pid.hp_l; hi = pid.hi_l; hd = pid.hd_l; h_base = pid.h_base_l; } pid.Ek = pid.set_tem - pid.now_tem; pid.Pout = pid.Kp * pid.Ek; // Proportional output pid.SEk += pid.Ek; // Total historical deviation DelEk = pid.Ek - pid.Ek_prev; // The difference between the last two deviations // no integral when the deviation is too large if (pid.now_tem < pid.set_tem - 3) { pid.SEk = 0; } // SEk limit, updated func, remain a little heater power when the compressor is running in full state if (pid.SEk < - (h_base - 10) / hi) { pid.SEk = - (h_base - 10) / hi; } if (pid.c_speed == max_speed_count) { pid.SEk = 0; } float Error_calc = pid.SEk; if (Error_calc < - (h_base + hp * delta_t) / hi) { Error_calc = - (h_base + hp * delta_t) / hi; } if (pid.c_speed == max_speed_count) { Error_calc = 0; } // ti=pid.t/pid.Ti; // ki=ti*pid.Kp; pid.Iout = pid.Ki * pid.SEk; // integral output // td=pid.Td/pid.t; // kd=pid.Kp*td; pid.Dout = pid.Kd * DelEk; // difference output if (pid.Dout < 0) { pid.Dout = 0 - pid.Dout; } // out= pid.Pout+pid.Iout+ pid.Dout; out = pid.Pout; if (out > pid.pwmcycle) { pid.OUT = pid.pwmcycle; } else if (out <= 0) { pid.OUT = pid.OUT0; } else { pid.OUT = out; } // heater percent pid.h_percent = calc_hp(delta_t, Error_calc, DelEk, h_base, hp, hi, hd); // close heater when compressor is running in full state if (pid.c_speed == max_speed_count) { pid.h_percent = 0; } set_compressor_power(pid.c_speed); set_heater_power(pid.h_percent); pid.Ek_prev = pid.Ek; // udpate difference pid.C1ms = 0; }