/* =============================================================================
 * pid.c - 位置式/增量式 PID(自 legacy Control/PID 原样移植)
 * 用法:
 *   PID_PositionStructureInit(pid, need)             初始化
 *   PID_PositionSetParameter(pid, kp, ki, kd)        设置增益
 *   PID_PositionSetEkRange(pid, lo, hi)              误差死区(|ek|在区间内视为0)
 *   PID_PositionSetOUTRange(pid, lo, hi)             输出限幅
 *   PID_PositionCalc(pid, now)                       每周期计算,结果在 pid->OUT
 *   PID_PositionClean(pid)                           清误差与积分(模式切换时)
 * 注意: 积分无独立限幅,靠输出限幅+死区约束;所有云台/底盘 PID 参数集中在
 *       robot_param.h,控制周期 2ms(与 legacy 调参时一致,勿随意改周期)
 * ========================================================================== */
#include "pid.h"

void PID_PositionStructureInit(PID_PositionTypeDef * pid, float need_value)
{
    pid->Need_Value = need_value;
    pid->Ek = 0;
    pid->Sum_Ek = 0;
    pid->Ek_low = 0;
    pid->Ek_up = 0;
    pid->Kp = 0;
    pid->Ki = 0;
    pid->Kd = 0;
    pid->OUT_low = -1e10;
    pid->OUT_up = 1e10;
}

void PID_PositionSetParameter(PID_PositionTypeDef * pid, float kp, float ki, float kd)
{
    pid->Kp = kp;
    pid->Ki = ki;
    pid->Kd = kd;
}

void PID_PositionSetEkRange(PID_PositionTypeDef * pid, float ek_low, float ek_up)
{
    pid->Ek_low = ek_low;
    pid->Ek_up = ek_up;
}

void PID_PositionSetOUTRange(PID_PositionTypeDef * pid, float out_low, float out_up)
{
    pid->OUT_low = out_low;
    pid->OUT_up = out_up;
}

void PID_PositionClean(PID_PositionTypeDef * pid)
{
    pid->Ek = 0;
    pid->Sum_Ek = 0;
}

void PID_PositionCalc(PID_PositionTypeDef * pid, float now_value)
{
    pid->Now_Value = now_value;
    pid->Ek_1 = pid->Ek;
    pid->Ek = pid->Need_Value - pid->Now_Value;
    if (pid->Ek_low < pid->Ek && pid->Ek < pid->Ek_up)  // 误差为0检测
        pid->Ek = 0;
    pid->Sum_Ek += pid->Ek;
    pid->Del_Ek = pid->Ek - pid->Ek_1;

    pid->P_OUT = pid->Kp * pid->Ek;
    pid->I_OUT = pid->Ki * pid->Sum_Ek;
    pid->D_OUT = pid->Kd * pid->Del_Ek;
    pid->OUT = pid->P_OUT + pid->I_OUT + pid->D_OUT;

    if (pid->OUT < pid->OUT_low)  // 输出限幅
        pid->OUT = pid->OUT_low;
    if (pid->OUT > pid->OUT_up)
        pid->OUT = pid->OUT_up;
}

void PID_IncrementalStructureInit(PID_IncrementalTypeDef * pid, float need_value)
{
    pid->Need_Value = need_value;
    pid->Ek = 0;
    pid->Ek_1 = 0;
    pid->Ek_low = 0;
    pid->Ek_up = 0;
    pid->Kp = 0;
    pid->Ki = 0;
    pid->Kd = 0;
    pid->OUT_low = -1e10;
    pid->OUT_up = 1e10;
}

void PID_IncrementalSetParameter(PID_IncrementalTypeDef * pid, float kp, float ki, float kd)
{
    pid->Kp = kp;
    pid->Ki = ki;
    pid->Kd = kd;
}

void PID_IncrementalSetEkRange(PID_IncrementalTypeDef * pid, float ek_low, float ek_up)
{
    pid->Ek_low = ek_low;
    pid->Ek_up = ek_up;
}

void PID_IncrementalSetOUTRange(PID_IncrementalTypeDef * pid, float out_low, float out_up)
{
    pid->OUT_low = out_low;
    pid->OUT_up = out_up;
}

void PID_IncrementalCalc(PID_IncrementalTypeDef * pid, float now_value)
{
    pid->Now_Value = now_value;
    pid->Ek_2 = pid->Ek_1;
    pid->Ek_1 = pid->Ek;
    pid->Ek = pid->Need_Value - pid->Now_Value;
    if (pid->Ek_low < pid->Ek && pid->Ek < pid->Ek_up)  // 误差为0检测
        pid->Ek = 0;

    pid->P_OUT = pid->Kp * (pid->Ek - pid->Ek_1);
    pid->I_OUT = pid->Ki * pid->Ek;
    pid->D_OUT = pid->Kd * (pid->Ek - 2 * pid->Ek_1 + pid->Ek_2);
    pid->OUT = pid->P_OUT + pid->I_OUT + pid->D_OUT;

    if (pid->OUT < pid->OUT_low)  // 输出限幅
        pid->OUT = pid->OUT_low;
    if (pid->OUT > pid->OUT_up)
        pid->OUT = pid->OUT_up;
}