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SpotMicroESP32-Leika/esp32/include/gait/walk_state.h
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2025-09-04 17:33:25 +02:00

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C++

#pragma once
#include <gait/state.h>
#include <utils/math_utils.h>
#include <array>
#include <functional>
enum class WALK_GAIT { TROT, CRAWL };
class WalkState : public GaitState {
private:
WALK_GAIT mode = WALK_GAIT::TROT;
float phase_time = 0.0f;
float phase_offset[4] = {0.f, 0.5f, 0.5f, 0.f};
float stand_offset = 0.6f;
float step_length = 0.0f;
float phase_lead = 0.08f;
float feather = 0.05f;
float speed_factor = 1;
float com_shift_gain = 0.35f;
float com_shift_limit = 0.06f;
float com_tau = 0.12f;
alignas(16) float crawl_target_xz[4][2] = {{0}};
int crawl_order[4] = {0, 1, 2, 3};
static float d2(float ax, float az, float bx, float bz) {
float dx = ax - bx, dz = az - bz;
return std::sqrt(dx * dx + dz * dz);
}
void buildCrawlTargetsIncenter() {
for (int s = 0; s < 4; ++s) {
int a = (s + 1) & 3, b = (s + 2) & 3, c = (s + 3) & 3;
float Ax = default_feet_pos[a][0], Az = default_feet_pos[a][2];
float Bx = default_feet_pos[b][0], Bz = default_feet_pos[b][2];
float Cx = default_feet_pos[c][0], Cz = default_feet_pos[c][2];
float la = d2(Bx, Bz, Cx, Cz);
float lb = d2(Ax, Az, Cx, Cz);
float lc = d2(Ax, Az, Bx, Bz);
float L = la + lb + lc;
if (L <= 1e-6f) {
crawl_target_xz[s][0] = (Ax + Bx + Cx) / 3.f;
crawl_target_xz[s][1] = (Az + Bz + Cz) / 3.f;
} else {
crawl_target_xz[s][0] = (la * Ax + lb * Bx + lc * Cx) / L;
crawl_target_xz[s][1] = (la * Az + lb * Bz + lc * Cz) / L;
}
}
}
static constexpr uint8_t BEZIER_POINTS = 12;
static constexpr std::array<float, BEZIER_POINTS> COMBINATORIAL_VALUES = {
combinatorial_constexpr(11, 0), // 1
combinatorial_constexpr(11, 1), // 11
combinatorial_constexpr(11, 2), // 55
combinatorial_constexpr(11, 3), // 165
combinatorial_constexpr(11, 4), // 330
combinatorial_constexpr(11, 5), // 462
combinatorial_constexpr(11, 6), // 462
combinatorial_constexpr(11, 7), // 330
combinatorial_constexpr(11, 8), // 165
combinatorial_constexpr(11, 9), // 55
combinatorial_constexpr(11, 10), // 11
combinatorial_constexpr(11, 11) // 1
};
alignas(32) static constexpr float BEZIER_STEPS[12] = {-1.0f, -1.4f, -1.5f, -1.5f, -1.5f, 0.0f,
0.0f, 0.0f, 1.5f, 1.5f, 1.4f, 1.0f};
alignas(32) static constexpr float BEZIER_HEIGHTS[12] = {0.0f, 0.0f, 0.9f, 0.9f, 0.9f, 0.9f,
0.9f, 1.1f, 1.1f, 1.1f, 0.0f, 0.0f};
public:
WalkState() { buildCrawlTargetsIncenter(); }
const char *name() const override { return "Bezier"; }
void set_mode_crawl(float duty = 0.85f, std::array<int, 4> order = {0, 1, 2, 3}) {
mode = WALK_GAIT::CRAWL;
speed_factor = 0.1;
stand_offset = duty;
const float base[4] = {0.f, 0.25f, 0.5f, 0.75f};
for (int i = 0; i < 4; ++i) phase_offset[order[i]] = base[i];
}
void set_mode_trot(float duty = 0.6f, std::array<float, 4> offsets = {0.f, 0.5f, 0.5f, 0.f}) {
mode = WALK_GAIT::TROT;
speed_factor = 1;
stand_offset = duty;
for (int i = 0; i < 4; ++i) phase_offset[i] = std::fmod(std::fabs(offsets[i]), 1.f);
}
void step(body_state_t &body_state, CommandMsg command, float dt = 0.02f) override {
this->mapCommand(command);
step_length = std::hypot(gait_state.step_x, gait_state.step_z);
if (gait_state.step_x < 0.0f) step_length = -step_length;
updatePhase(dt);
updateBodyPosition(body_state, dt);
updateFeetPositions(body_state);
}
protected:
void updatePhase(float dt) {
phase_time = std::fmod(phase_time + dt * gait_state.step_velocity * speed_factor, 1.0f);
}
void updateBodyPosition(body_state_t &body_state, float dt) {
if (mode != WALK_GAIT::CRAWL) return;
const bool moving = gait_state.step_x != 0.f || gait_state.step_z != 0.f || gait_state.step_angle != 0.f;
const float a = dt / (com_tau + dt);
if (!moving) {
body_state.xm += (0.f - body_state.xm) * a;
body_state.zm += (0.f - body_state.zm) * a;
return;
}
int k = (int)std::floor(std::fmod(phase_time, 1.f) * 8.f) & 7;
int leg = crawl_order[k >> 1];
float tx = crawl_target_xz[leg][0] * com_shift_gain;
float tz = crawl_target_xz[leg][1] * com_shift_gain;
float m = std::hypot(tx, tz);
if (m > com_shift_limit) {
float s = com_shift_limit / m;
tx *= s;
tz *= s;
}
body_state.xm += (tx - body_state.xm) * a;
body_state.zm += (tz - body_state.zm) * a;
}
static float smoothstep01(float t) {
const float x = std::clamp(t, 0.f, 1.f);
return x * x * (3.f - 2.f * x);
}
void updateFeetPositions(body_state_t &body_state) {
for (int i = 0; i < 4; ++i) updateFootPosition(body_state, i);
}
void updateFootPosition(body_state_t &body_state, const int index) {
body_state.feet[index][0] = this->default_feet_pos[index][0];
body_state.feet[index][1] = this->default_feet_pos[index][1];
body_state.feet[index][2] = this->default_feet_pos[index][2];
const float leg_phase = std::fmod(phase_time + phase_offset[index], 1.0f);
const bool contact = leg_phase <= stand_offset;
if (contact)
standController(body_state, index, leg_phase / stand_offset);
else
swingController(body_state, index, (leg_phase - stand_offset) / (1.f - stand_offset));
}
void standController(body_state_t &body_state, const int index, const float phase) {
controller(index, body_state, phase, stanceCurve, &gait_state.step_depth);
}
void swingController(body_state_t &body_state, const int index, const float phase) {
controller(index, body_state, phase, bezierCurve, &gait_state.step_height);
}
void controller(const int index, body_state_t &body_state, const float phase,
std::function<void(float, float, float *, float, float *)> curve, float *arg) {
float delta_pos[3] = {0};
float delta_rot[3] = {0};
float length = step_length * 0.5f;
float angle = std::atan2(gait_state.step_z, step_length);
curve(length, angle, arg, phase, delta_pos);
length = gait_state.step_angle * 2.0f;
angle = yawArc(default_feet_pos[index], body_state.feet[index]);
curve(length, angle, arg, phase, delta_rot);
body_state.feet[index][0] += delta_pos[0] + delta_rot[0] * 0.2;
if (step_length || gait_state.step_angle) body_state.feet[index][1] += delta_pos[1] + delta_rot[1] * 0.2;
body_state.feet[index][2] += delta_pos[2] + delta_rot[2] * 0.2;
}
static void stanceCurve(const float length, const float angle, const float *depth, const float phase,
float *point) {
float step = length * (1.0f - 2.0f * phase);
point[0] += step * std::cos(angle);
point[2] += step * std::sin(angle);
if (length != 0.0f) point[1] = -*depth * std::cos((M_PI * (point[0] + point[2])) / (2.f * length));
}
static void bezierCurve(const float length, const float angle, const float *height, const float phase,
float *point) {
const float X_POLAR = std::cos(angle);
const float Z_POLAR = std::sin(angle);
const float t = std::clamp(phase, 1e-4f, 1.f - 1e-4f);
float phase_power = 1.0f;
float inv_phase_power = std::pow(1.0f - t, 11);
const float one_minus_phase = 1.0f - t;
for (int i = 0; i < 12; i++) {
float b = COMBINATORIAL_VALUES[i] * phase_power * inv_phase_power;
point[0] += b * BEZIER_STEPS[i] * length * X_POLAR;
point[1] += b * BEZIER_HEIGHTS[i] * *height;
point[2] += b * BEZIER_STEPS[i] * length * Z_POLAR;
phase_power *= phase;
inv_phase_power /= one_minus_phase;
}
}
static float yawArc(const float feet_pos[3], const float *current_pos) {
const float foot_mag = std::hypot(feet_pos[0], feet_pos[2]);
const float foot_dir = std::atan2(feet_pos[2], feet_pos[0]);
const float offsets[] = {current_pos[0] - feet_pos[0], current_pos[1] - feet_pos[1],
current_pos[2] - feet_pos[2]};
const float offset_mag = std::hypot(offsets[0], offsets[2]);
const float offset_mod = std::atan2(offset_mag, foot_mag);
return (float)M_PI_2 + foot_dir + offset_mod;
}
};