我正在尝试在 arduino 控制的四足动物上实现逆运动学,但我得到了一些不准确的计算结果。为了检查出了什么问题,我将算法移植到 C++ 并在 PC 上运行。我的问题是我会假设坐标变化会产生相同的结果,无论我改变坐标的哪个方向。但是 x 和 y 轴上的过渡会产生几度差异,具体取决于方向。我的数学知识有点尘土飞扬,所以也许我在检查算法时错过了一些东西。腿的配置是这样的http://te.unib.ac.id/lecturer/indraagustian/wp-content/uploads/2014/05/逆运动学.jpg
什么可能导致结果的差异?
#include <cmath>
#include <iostream>
#define CONNECTED_SERVOS 12
#define PI 3.1415
#define coxa 55
#define femur 40
#define tibia 47
int nogo_buffer[CONNECTED_SERVOS];
int end_position[CONNECTED_SERVOS];
int cur_pw[CONNECTED_SERVOS];
int calibrate[] = { 1500, 1520, 1500, 1560, 1400, 1410, 1520, 1550, 1500, 1560, 1510, 1620 }; //calibrate servos to simmetrical positions
int floatToInt(double num) {
//Rounding a number avoiding truncation:
return (int)(num < 0 ? (num - 0.5) : (num + 0.5));
}
int radToMicro(double rad, int ref) {
//Make sure rad isn't negative:
if (rad < 0) {
while (rad < -PI) {
rad += PI;
}
}
else {
while (rad > PI) {
rad -= PI;
}
}
//edit 2400
return ref - floatToInt(572.958 * rad);
}
void IkLeg(int x, int y, int z, int nLeg)
{
double L1 = sqrt(pow(x,2) + pow(z,2));
double L = sqrt(pow(L1 - coxa,2) + pow(y,2));
double t = acos((pow(tibia,2) + pow(femur,2) - pow(L,2)) / (2 * tibia * femur)) / PI * 180;
double f1 = acos(y / L) / PI * 180;
double f2 = acos((pow(femur,2) + pow(L,2) - pow(tibia,2)) / (2 * femur * L)) / PI * 180;
double f = f1 + f2;
double c = atan2(z, x) / PI * 180;
std::cout << c << std::endl;
std::cout << f-90 << std::endl;
std::cout << t-90 << std::endl;
//coxa angle
nogo_buffer[3 * nLeg - 1] = radToMicro(c/180*PI, calibrate[3 * nLeg - 1]);
std::cout << nogo_buffer[3 * nLeg - 1] << std::endl;
//femur angle
nogo_buffer[3 * nLeg - 2] = radToMicro(f / 180 * PI, calibrate[3 * nLeg - 2]+900);
std::cout << nogo_buffer[3 * nLeg - 2] << std::endl;
//tibia angle
nogo_buffer[3 * nLeg - 3] = radToMicro(t / 180 * PI, calibrate[3 * nLeg - 3]+900);
std::cout << nogo_buffer[3 * nLeg - 3] << std::endl;
}
int main() {
IkLeg(95,47,0,1);
std::cout << "x transition" << std::endl;
IkLeg(105, 47, 0, 1);
IkLeg(85, 47, 0, 1);
std::cout << "y transition" << std::endl;
IkLeg(95, 57, 0, 1);
IkLeg(95, 37, 0, 1);
std::cout << "z transition" << std::endl;
IkLeg(95, 47, 30, 1);
IkLeg(95, 47, -30, 1);
return 0;
}