From e2501a5674fa8121290320382e35e3b67045b187 Mon Sep 17 00:00:00 2001 From: Tyler Veness Date: Fri, 28 Jun 2024 21:42:29 -0700 Subject: [PATCH] Clean up FRC 2022 shooter example coordinate systems (#580) --- examples/FRC2022Shooter/main.py | 95 ++++++++++++++-------------- examples/FRC2022Shooter/src/Main.cpp | 92 +++++++++++++++------------ 2 files changed, 101 insertions(+), 86 deletions(-) diff --git a/examples/FRC2022Shooter/main.py b/examples/FRC2022Shooter/main.py index 7aa0c084..13cad9c1 100755 --- a/examples/FRC2022Shooter/main.py +++ b/examples/FRC2022Shooter/main.py @@ -16,32 +16,29 @@ import numpy as np from numpy.linalg import norm -field_width = 8.2296 # 27 ft -field_length = 16.4592 # 54 ft +field_width = 8.2296 # 27 ft -> m +field_length = 16.4592 # 54 ft -> m +target_wrt_field = np.array( + [[field_length / 2.0], [field_width / 2.0], [2.64], [0.0], [0.0], [0.0]] +) +target_radius = 0.61 g = 9.806 # m/s² -def main(): - # Robot initial velocity - robot_initial_v_x = 0.2 # ft/s - robot_initial_v_y = -0.2 # ft/s - robot_initial_v_z = 0.0 # ft/s +def lerp(a, b, t): + return a + t * (b - a) - max_launch_velocity = 10.0 - shooter = np.array([[field_length / 4.0], [field_width / 4.0], [1.2]]) - shooter_x = shooter[0, 0] - shooter_y = shooter[1, 0] - shooter_z = shooter[2, 0] +def main(): + # Robot initial state + robot_wrt_field = np.array( + [[field_length / 4.0], [field_width / 4.0], [0.0], [1.524], [-1.524], [0.0]] + ) - target = np.array([[field_length / 2.0], [field_width / 2.0], [2.64]]) - target_x = target[0, 0] - target_y = target[1, 0] - target_z = target[2, 0] - target_radius = 0.61 + max_launch_velocity = 10.0 # m/s - def lerp(a, b, t): - return a + t * (b - a) + shooter_wrt_robot = np.array([[0.0], [0.0], [1.2], [0.0], [0.0], [0.0]]) + shooter_wrt_field = robot_wrt_field + shooter_wrt_robot problem = OptimizationProblem() @@ -52,6 +49,8 @@ def lerp(a, b, t): T.set_value(1) dt = T / N + # Ball state in field frame + # # [x position] # [y position] # [z position] @@ -60,42 +59,46 @@ def lerp(a, b, t): # [z velocity] X = problem.decision_variable(6, N) + p = X[:3, :] p_x = X[0, :] p_y = X[1, :] p_z = X[2, :] + + v = X[3:, :] v_x = X[3, :] v_y = X[4, :] v_z = X[5, :] # Position initial guess is linear interpolation between start and end position for k in range(N): - p_x[k].set_value(lerp(shooter_x, target_x, k / N)) - p_y[k].set_value(lerp(shooter_y, target_y, k / N)) - p_z[k].set_value(lerp(shooter_z, target_z, k / N)) + p_x[k].set_value(lerp(shooter_wrt_field[0, 0], target_wrt_field[0, 0], k / N)) + p_y[k].set_value(lerp(shooter_wrt_field[1, 0], target_wrt_field[1, 0], k / N)) + p_z[k].set_value(lerp(shooter_wrt_field[2, 0], target_wrt_field[2, 0], k / N)) # Velocity initial guess is max launch velocity toward goal - uvec_shooter_to_target = target - shooter + uvec_shooter_to_target = target_wrt_field[:3, :] - shooter_wrt_field[:3, :] uvec_shooter_to_target /= norm(uvec_shooter_to_target) for k in range(N): - v_x[k].set_value(max_launch_velocity * uvec_shooter_to_target[0, 0]) - v_y[k].set_value(max_launch_velocity * uvec_shooter_to_target[1, 0]) - v_z[k].set_value(max_launch_velocity * uvec_shooter_to_target[2, 0]) + v[:, k].set_value( + robot_wrt_field[3:, :] + max_launch_velocity * uvec_shooter_to_target + ) # Shooter initial position - problem.subject_to(X[:3, 0] == shooter) + problem.subject_to(p[:, 0] == shooter_wrt_field[:3, 0]) # Require initial launch velocity is below max # # √{v_x² + v_y² + v_z²) ≤ vₘₐₓ # v_x² + v_y² + v_z² ≤ vₘₐₓ² problem.subject_to( - v_x[0] ** 2 + v_y[0] ** 2 + v_z[0] ** 2 <= max_launch_velocity**2 + (v_x[0] - robot_wrt_field[3, 0]) ** 2 + + (v_y[0] - robot_wrt_field[4, 0]) ** 2 + + (v_z[0] - robot_wrt_field[5, 0]) ** 2 + <= max_launch_velocity**2 ) # Require final position is in center of target circle - problem.subject_to(p_x[-1] == target_x) - problem.subject_to(p_y[-1] == target_y) - problem.subject_to(p_z[-1] == target_z) + problem.subject_to(p[:, -1] == target_wrt_field[:3, :]) # Require the final velocity is down problem.subject_to(v_z[-1] < 0.0) @@ -115,9 +118,9 @@ def f(x): m = 2.0 # kg a_D = lambda v: 0.5 * rho * v**2 * C_D * A / m - v_x = x[3, 0] + robot_initial_v_x - v_y = x[4, 0] + robot_initial_v_y - v_z = x[5, 0] + robot_initial_v_z + v_x = x[3, 0] + v_y = x[4, 0] + v_z = x[5, 0] return VariableMatrix( [[v_x], [v_y], [v_z], [-a_D(v_x)], [-a_D(v_y)], [-g - a_D(v_z)]] ) @@ -140,16 +143,16 @@ def f(x): problem.solve(diagnostics=True) # Initial velocity vector - v = X[3:, 0].value() + v0 = X[3:, 0].value() - robot_wrt_field[3:, :] - launch_velocity = norm(v) + launch_velocity = norm(v0) print(f"Launch velocity = {launch_velocity:.03f} m/s") - pitch = math.atan2(v[2, 0], math.hypot(v[0, 0], v[1, 0])) - print(f"Pitch = {pitch * 180.0 / math.pi:.03f}°") + pitch = math.atan2(v0[2, 0], math.hypot(v0[0, 0], v0[1, 0])) + print(f"Pitch = {np.rad2deg(pitch):.03f}°") - yaw = math.atan2(v[1, 0], v[0, 0]) - print(f"Yaw = {yaw * 180.0 / math.pi:.03f}°") + yaw = math.atan2(v0[1, 0], v0[0, 0]) + print(f"Yaw = {np.rad2deg(yaw):.03f}°") print(f"Total time = {T.value():.03f} s") print(f"dt = {dt.value() * 1e3:.03f} ms") @@ -175,9 +178,9 @@ def plot_wireframe(ax, f, x_range, y_range, color): # Target ax.plot( - target_x, - target_y, - target_z, + target_wrt_field[0, 0], + target_wrt_field[1, 0], + target_wrt_field[2, 0], color="black", marker="x", ) @@ -185,9 +188,9 @@ def plot_wireframe(ax, f, x_range, y_range, color): ys = [] zs = [] for angle in np.arange(0.0, 2.0 * math.pi, 0.1): - xs.append(target_x + target_radius * math.cos(angle)) - ys.append(target_y + target_radius * math.sin(angle)) - zs.append(target_z) + xs.append(target_wrt_field[0, 0] + target_radius * math.cos(angle)) + ys.append(target_wrt_field[1, 0] + target_radius * math.sin(angle)) + zs.append(target_wrt_field[2, 0]) ax.plot(xs, ys, zs, color="black") # Trajectory diff --git a/examples/FRC2022Shooter/src/Main.cpp b/examples/FRC2022Shooter/src/Main.cpp index 5179eafa..f111f7d1 100644 --- a/examples/FRC2022Shooter/src/Main.cpp +++ b/examples/FRC2022Shooter/src/Main.cpp @@ -12,31 +12,33 @@ // This program finds the optimal initial launch velocity and launch angle for // the 2022 FRC game's target. -constexpr double field_width = 8.2296; // 27 ft -constexpr double field_length = 16.4592; // 54 ft -constexpr double g = 9.806; // m/s² +namespace slp = sleipnir; + +using Eigen::Vector3d; +using Vector6d = Eigen::Vector; + +constexpr double field_width = 8.2296; // 27 ft -> m +constexpr double field_length = 16.4592; // 54 ft -> m +constexpr Vector6d target_wrt_field{ + {field_length / 2.0}, {field_width / 2.0}, {2.64}, {0.0}, {0.0}, {0.0}}; +constexpr double g = 9.806; // m/s² #ifndef RUNNING_TESTS int main() { - // Robot initial velocity - double robot_initial_v_x = 0.2; // ft/s - double robot_initial_v_y = -0.2; // ft/s - double robot_initial_v_z = 0.0; // ft/s + // Robot initial state + constexpr Vector6d robot_wrt_field{{field_length / 4.0}, + {field_width / 4.0}, + {0.0}, + {1.524}, + {-1.524}, + {0.0}}; constexpr double max_launch_velocity = 10.0; - Eigen::Vector3d shooter{{field_length / 4.0}, {field_width / 4.0}, {1.2}}; - const auto& shooter_x = shooter(0, 0); - const auto& shooter_y = shooter(1, 0); - const auto& shooter_z = shooter(2, 0); - - constexpr Eigen::Vector3d target{ - {field_length / 2.0}, {field_width / 2.0}, {2.64}}; - const auto& target_x = target(0, 0); - const auto& target_y = target(1, 0); - const auto& target_z = target(2, 0); + Vector6d shooter_wrt_robot{{0.0}, {0.0}, {1.2}, {0.0}, {0.0}, {0.0}}; + Vector6d shooter_wrt_field = robot_wrt_field + shooter_wrt_robot; - sleipnir::OptimizationProblem problem; + slp::OptimizationProblem problem; // Set up duration decision variables constexpr int N = 10; @@ -45,6 +47,8 @@ int main() { T.SetValue(1); auto dt = T / N; + // Ball state in field frame + // // [x position] // [y position] // [z position] @@ -53,9 +57,12 @@ int main() { // [z velocity] auto X = problem.DecisionVariable(6, N); + auto p = X.Block(0, 0, 3, N); auto p_x = X.Row(0); auto p_y = X.Row(1); auto p_z = X.Row(2); + + auto v = X.Block(3, 0, 3, N); auto v_x = X.Row(3); auto v_y = X.Row(4); auto v_z = X.Row(5); @@ -63,38 +70,42 @@ int main() { // Position initial guess is linear interpolation between start and end // position for (int k = 0; k < N; ++k) { - p_x(k).SetValue(std::lerp(shooter_x, target_x, static_cast(k) / N)); - p_y(k).SetValue(std::lerp(shooter_y, target_y, static_cast(k) / N)); - p_z(k).SetValue(std::lerp(shooter_z, target_z, static_cast(k) / N)); + p_x(k).SetValue(std::lerp(shooter_wrt_field(0), target_wrt_field(0), + static_cast(k) / N)); + p_y(k).SetValue(std::lerp(shooter_wrt_field(1), target_wrt_field(1), + static_cast(k) / N)); + p_z(k).SetValue(std::lerp(shooter_wrt_field(2), target_wrt_field(2), + static_cast(k) / N)); } // Velocity initial guess is max launch velocity toward goal - Eigen::Vector3d uvec_shooter_to_target = (target - shooter).normalized(); + Vector3d uvec_shooter_to_target = + (target_wrt_field.block(0, 0, 3, 1) - shooter_wrt_field.block(0, 0, 3, 1)) + .normalized(); for (int k = 0; k < N; ++k) { - v_x(k).SetValue(max_launch_velocity * uvec_shooter_to_target(0, 0)); - v_y(k).SetValue(max_launch_velocity * uvec_shooter_to_target(1, 0)); - v_z(k).SetValue(max_launch_velocity * uvec_shooter_to_target(2, 0)); + v.Col(k).SetValue(robot_wrt_field.block(3, 0, 3, 1) + + max_launch_velocity * uvec_shooter_to_target); } // Shooter initial position - problem.SubjectTo(X.Block(0, 0, 3, 1) == shooter); + problem.SubjectTo(p.Col(0) == shooter_wrt_field.block(0, 0, 3, 1)); // Require initial launch velocity is below max // // √{v_x² + v_y² + v_z²) ≤ vₘₐₓ // v_x² + v_y² + v_z² ≤ vₘₐₓ² - problem.SubjectTo(v_x(0) * v_x(0) + v_y(0) * v_y(0) + v_z(0) * v_z(0) <= + problem.SubjectTo(slp::pow(v_x(0) - robot_wrt_field(3), 2) + + slp::pow(v_y(0) - robot_wrt_field(4), 2) + + slp::pow(v_z(0) - robot_wrt_field(5), 2) <= max_launch_velocity * max_launch_velocity); // Require final position is in center of target circle - problem.SubjectTo(p_x(N - 1) == target_x); - problem.SubjectTo(p_y(N - 1) == target_y); - problem.SubjectTo(p_z(N - 1) == target_z); + problem.SubjectTo(p.Col(N - 1) == target_wrt_field.block(0, 0, 3, 1)); // Require the final velocity is down problem.SubjectTo(v_z(N - 1) < 0.0); - auto f = [&](sleipnir::VariableMatrix x) { + auto f = [](slp::VariableMatrix x) { // x' = x' // y' = y' // z' = z' @@ -109,11 +120,11 @@ int main() { constexpr double m = 2.0; // kg auto a_D = [](auto v) { return 0.5 * rho * v * v * C_D * A / m; }; - auto v_x = x(3, 0) + robot_initial_v_x; - auto v_y = x(4, 0) + robot_initial_v_y; - auto v_z = x(5, 0) + robot_initial_v_z; - return sleipnir::VariableMatrix{{v_x}, {v_y}, {v_z}, - {-a_D(v_x)}, {-a_D(v_y)}, {-g - a_D(v_z)}}; + auto v_x = x(3, 0); + auto v_y = x(4, 0); + auto v_z = x(5, 0); + return slp::VariableMatrix{{v_x}, {v_y}, {v_z}, + {-a_D(v_x)}, {-a_D(v_y)}, {-g - a_D(v_z)}}; }; // Dynamics constraints - RK4 integration @@ -135,15 +146,16 @@ int main() { problem.Solve({.diagnostics = true}); // Initial velocity vector - Eigen::Vector3d v = X.Block(3, 0, 3, 1).Value(); + Eigen::Vector3d v0 = + X.Block(3, 0, 3, 1).Value() - robot_wrt_field.block(3, 0, 3, 1); - double launch_velocity = v.norm(); + double launch_velocity = v0.norm(); std::println("Launch velocity = {:.03} ms", launch_velocity); - double pitch = std::atan2(v(2), std::hypot(v(0), v(1))); + double pitch = std::atan2(v0(2), std::hypot(v0(0), v0(1))); std::println("Pitch = {:.03}°", pitch * 180.0 / std::numbers::pi); - double yaw = std::atan2(v(1), v(0)); + double yaw = std::atan2(v0(1), v0(0)); std::println("Yaw = {:.03}°", yaw * 180.0 / std::numbers::pi); std::println("Total time = {:.03} s", T.Value());