#include "balance.h"
#include "stdint.h"
#include "arm_math.h"

/**
 * @brief 根据状态反馈计算当前腿长,查表获得LQR的反馈增益,并列式计算LQR的输出
 * @note 得到的腿部力矩输出还要经过综合运动控制系统补偿后映射为两个关节电机输出
 *
 */
static void CalcLQR(LinkNPodParam *p, ChassisParam *chassis)
{
    static float k[12][3] = {91.443258,-113.149301,-8.780431,
    2.186397,-6.908826,-0.171192,
    47.943203,-39.423913,-13.297140,
    30.671413,-28.308799,-9.363969,
    231.778706,-224.742110,68.974495,
    18.910995,-20.079072,7.490403,
    50.114072,-58.670210,23.856863,
    3.273746,-3.321150,1.267603,
    140.969395,-137.481822,42.507159,
    93.859327,-90.754295,27.811839,
    -283.581279,232.017305,87.865897,
    -28.193619,23.802666,3.963794,};
    float T[2] = {0};       // 0 T_wheel  1 T_hip
    float l = p->leg_len;
    float lsqr = l * l;

    uint8_t i, j;

    // 离地时轮子输出置0
    i = 0; j = i * 6;
    T[i] = p->fly_flag ? 0 :
           ((k[j + 0][0] * lsqr + k[j + 0][1] * l + k[j + 0][2]) * -p->theta +
            (k[j + 1][0] * lsqr + k[j + 1][1] * l + k[j + 1][2]) * -p->theta_w + 
            (k[j + 2][0] * lsqr + k[j + 2][1] * l + k[j + 2][2]) * (chassis->target_dist - chassis->dist) +
            (k[j + 3][0] * lsqr + k[j + 3][1] * l + k[j + 3][2]) * (chassis->target_v - chassis->vel) +
            (k[j + 4][0] * lsqr + k[j + 4][1] * l + k[j + 4][2]) * -chassis->pitch +
            (k[j + 5][0] * lsqr + k[j + 5][1] * l + k[j + 5][2]) * -chassis->pitch_w);
    
    // 离地时关节输出仅保留 theta 和 theta_dot，保证滞空时腿部竖直
    i = 1; j = i * 6;
    T[i] = (k[j + 0][0] * lsqr + k[j + 0][1] * l + k[j + 0][2]) * -p->theta +
           (k[j + 1][0] * lsqr + k[j + 1][1] * l + k[j + 1][2]) * -p->theta_w + (p->fly_flag ? 0 :
           ((k[j + 2][0] * lsqr + k[j + 2][1] * l + k[j + 2][2]) * (chassis->target_dist - chassis->dist) +
            (k[j + 3][0] * lsqr + k[j + 3][1] * l + k[j + 3][2]) * (chassis->target_v - chassis->vel) +
            (k[j + 4][0] * lsqr + k[j + 4][1] * l + k[j + 4][2]) * -chassis->pitch +
            (k[j + 5][0] * lsqr + k[j + 5][1] * l + k[j + 5][2]) * -chassis->pitch_w));
    
    p->T_wheel = T[0];
    p->T_hip = T[1];
}