/**
* create and score a trajectory given the current pose of the robot and selected velocities
*/
void CalibrateAction::generateTrajectory(
double x, double y, double theta,
double vx, double vy, double vtheta, double sim_time_, double vx_samp, double vy_samp, double vtheta_samp,
double acc_x, double acc_y, double acc_theta, Trajectory& traj) {
double x_i = x;
double y_i = y;
double theta_i = theta;
double vx_i, vy_i, vtheta_i;
vx_i = vx;
vy_i = vy;
vtheta_i = vtheta;
//compute the number of steps we must take along this trajectory to be "safe"
int num_steps = int(sim_time_ / traj_sim_granularity_ + 0.5);
//we at least want to take one step... even if we won't move, we want to score our current position
if(num_steps == 0) {
num_steps = 1;
}
double dt = sim_time_ / num_steps;
//create a potential trajectory
traj.resetPoints();
traj.xv_ = vx_i;
traj.yv_ = vy_i;
traj.thetav_ = vtheta_i;
for(int i = 0; i < num_steps; ++i){
//the point is legal... add it to the trajectory
traj.addPoint(x_i, y_i, theta_i);
//calculate velocities
vx_i = computeNewVelocity(vx_samp, vx_i, acc_x, dt);
vy_i = computeNewVelocity(vy_samp, vy_i, acc_y, dt);
vtheta_i = computeNewVelocity(vtheta_samp, vtheta_i, acc_theta, dt);
//calculate positions
x_i = computeNewXPosition(x_i, vx_i, vy_i, theta_i, dt);
y_i = computeNewYPosition(y_i, vx_i, vy_i, theta_i, dt);
theta_i = computeNewThetaPosition(theta_i, vtheta_i, dt);
} // end for i < numsteps
}
bool SimpleScoredSamplingPlanner::findBestTrajectory(Trajectory& traj, std::vector<Trajectory>* all_explored) {
Trajectory loop_traj;
Trajectory best_traj;
double loop_traj_cost, best_traj_cost = -1;
bool gen_success;
int count, count_valid;
for (std::vector<TrajectoryCostFunction*>::iterator loop_critic = critics_.begin(); loop_critic != critics_.end(); ++loop_critic) {
TrajectoryCostFunction* loop_critic_p = *loop_critic;
if (loop_critic_p->prepare() == false) {
ROS_WARN("A scoring function failed to prepare");
return false;
}
}
for (std::vector<TrajectorySampleGenerator*>::iterator loop_gen = gen_list_.begin(); loop_gen != gen_list_.end(); ++loop_gen) {
count = 0;
count_valid = 0;
TrajectorySampleGenerator* gen_ = *loop_gen;
while (gen_->hasMoreTrajectories()) {
gen_success = gen_->nextTrajectory(loop_traj);
if (gen_success == false) {
// TODO use this for debugging
continue;
}
loop_traj_cost = scoreTrajectory(loop_traj, best_traj_cost);
if (all_explored != NULL) {
loop_traj.cost_ = loop_traj_cost;
all_explored->push_back(loop_traj);
}
if (loop_traj_cost >= 0) {
count_valid++;
if (best_traj_cost < 0 || loop_traj_cost < best_traj_cost) {
best_traj_cost = loop_traj_cost;
best_traj = loop_traj;
}
}
count++;
if (max_samples_ > 0 && count >= max_samples_) {
break;
}
}
if (best_traj_cost >= 0) {
traj.xv_ = best_traj.xv_;
traj.yv_ = best_traj.yv_;
traj.thetav_ = best_traj.thetav_;
traj.cost_ = best_traj_cost;
traj.resetPoints();
double px, py, pth;
for (unsigned int i = 0; i < best_traj.getPointsSize(); i++) {
best_traj.getPoint(i, px, py, pth);
traj.addPoint(px, py, pth);
}
}
ROS_DEBUG("Evaluated %d trajectories, found %d valid", count, count_valid);
if (best_traj_cost >= 0) {
// do not try fallback generators
break;
}
}
return best_traj_cost >= 0;
}
/**
* create and score a trajectory given the current pose of the robot and selected velocities
*/
void TrajectoryPlanner::generateTrajectory(
double x, double y, double theta,
double vx, double vy, double vtheta,
double vx_samp, double vy_samp, double vtheta_samp,
double acc_x, double acc_y, double acc_theta,
double impossible_cost,
Trajectory& traj) {
// make sure the configuration doesn't change mid run
boost::mutex::scoped_lock l(configuration_mutex_);
double x_i = x;
double y_i = y;
double theta_i = theta;
double vx_i, vy_i, vtheta_i;
vx_i = vx;
vy_i = vy;
vtheta_i = vtheta;
//compute the magnitude of the velocities
double vmag = sqrt(vx_samp * vx_samp + vy_samp * vy_samp);
//compute the number of steps we must take along this trajectory to be "safe"
int num_steps;
if(!heading_scoring_) {
num_steps = int(max((vmag * sim_time_) / sim_granularity_, fabs(vtheta_samp) / angular_sim_granularity_) + 0.5);
} else {
num_steps = int(sim_time_ / sim_granularity_ + 0.5);
}
//we at least want to take one step... even if we won't move, we want to score our current position
if(num_steps == 0) {
num_steps = 1;
}
double dt = sim_time_ / num_steps;
double time = 0.0;
//create a potential trajectory
traj.resetPoints();
traj.xv_ = vx_samp;
traj.yv_ = vy_samp;
traj.thetav_ = vtheta_samp;
traj.cost_ = -1.0;
//initialize the costs for the trajectory
double path_dist = 0.0;
double goal_dist = 0.0;
double occ_cost = 0.0;
double heading_diff = 0.0;
for(int i = 0; i < num_steps; ++i){
//get map coordinates of a point
unsigned int cell_x, cell_y;
//we don't want a path that goes off the know map
if(!costmap_.worldToMap(x_i, y_i, cell_x, cell_y)){
traj.cost_ = -1.0;
return;
}
//check the point on the trajectory for legality
double footprint_cost = footprintCost(x_i, y_i, theta_i);
//if the footprint hits an obstacle this trajectory is invalid
if(footprint_cost < 0){
traj.cost_ = -1.0;
return;
//TODO: Really look at getMaxSpeedToStopInTime... dues to discretization errors and high acceleration limits,
//it can actually cause the robot to hit obstacles. There may be something to be done to fix, but I'll have to
//come back to it when I have time. Right now, pulling it out as it'll just make the robot a bit more conservative,
//but safe.
/*
double max_vel_x, max_vel_y, max_vel_th;
//we want to compute the max allowable speeds to be able to stop
//to be safe... we'll make sure we can stop some time before we actually hit
getMaxSpeedToStopInTime(time - stop_time_buffer_ - dt, max_vel_x, max_vel_y, max_vel_th);
//check if we can stop in time
if(fabs(vx_samp) < max_vel_x && fabs(vy_samp) < max_vel_y && fabs(vtheta_samp) < max_vel_th){
ROS_ERROR("v: (%.2f, %.2f, %.2f), m: (%.2f, %.2f, %.2f) t:%.2f, st: %.2f, dt: %.2f", vx_samp, vy_samp, vtheta_samp, max_vel_x, max_vel_y, max_vel_th, time, stop_time_buffer_, dt);
//if we can stop... we'll just break out of the loop here.. no point in checking future points
break;
}
else{
traj.cost_ = -1.0;
return;
}
*/
}
occ_cost = std::max(std::max(occ_cost, footprint_cost), double(costmap_.getCost(cell_x, cell_y)));
//do we want to follow blindly
if (simple_attractor_) {
goal_dist = (x_i - global_plan_[global_plan_.size() -1].pose.position.x) *
(x_i - global_plan_[global_plan_.size() -1].pose.position.x) +
(y_i - global_plan_[global_plan_.size() -1].pose.position.y) *
(y_i - global_plan_[global_plan_.size() -1].pose.position.y);
} else {
bool update_path_and_goal_distances = true;
// with heading scoring, we take into account heading diff, and also only score
// path and goal distance for one point of the trajectory
if (heading_scoring_) {
if (time >= heading_scoring_timestep_ && time < heading_scoring_timestep_ + dt) {
heading_diff = headingDiff(cell_x, cell_y, x_i, y_i, theta_i);
} else {
update_path_and_goal_distances = false;
}
}
if (update_path_and_goal_distances) {
//update path and goal distances
path_dist = path_map_(cell_x, cell_y).target_dist;
goal_dist = goal_map_(cell_x, cell_y).target_dist;
//if a point on this trajectory has no clear path to goal it is invalid
if(impossible_cost <= goal_dist || impossible_cost <= path_dist){
// ROS_DEBUG("No path to goal with goal distance = %f, path_distance = %f and max cost = %f",
// goal_dist, path_dist, impossible_cost);
traj.cost_ = -2.0;
return;
}
}
}
//the point is legal... add it to the trajectory
traj.addPoint(x_i, y_i, theta_i);
//calculate velocities
vx_i = computeNewVelocity(vx_samp, vx_i, acc_x, dt);
vy_i = computeNewVelocity(vy_samp, vy_i, acc_y, dt);
vtheta_i = computeNewVelocity(vtheta_samp, vtheta_i, acc_theta, dt);
//calculate positions
x_i = computeNewXPosition(x_i, vx_i, vy_i, theta_i, dt);
y_i = computeNewYPosition(y_i, vx_i, vy_i, theta_i, dt);
theta_i = computeNewThetaPosition(theta_i, vtheta_i, dt);
//increment time
time += dt;
} // end for i < numsteps
//ROS_INFO("OccCost: %f, vx: %.2f, vy: %.2f, vtheta: %.2f", occ_cost, vx_samp, vy_samp, vtheta_samp);
double cost = -1.0;
if (!heading_scoring_) {
cost = pdist_scale_ * path_dist + goal_dist * gdist_scale_ + occdist_scale_ * occ_cost;
} else {
cost = occdist_scale_ * occ_cost + pdist_scale_ * path_dist + 0.3 * heading_diff + goal_dist * gdist_scale_;
}
traj.cost_ = cost;
}