void NavfnWithCostmap::poseCallback(const rm::PoseStamped::ConstPtr& goal) {
tf::Stamped<tf::Pose> global_pose;
cmap_->getRobotPose(global_pose);
vector<PoseStamped> path;
rm::PoseStamped start;
start.header.stamp = global_pose.stamp_;
start.header.frame_id = global_pose.frame_id_;
start.pose.position.x = global_pose.getOrigin().x();
start.pose.position.y = global_pose.getOrigin().y();
start.pose.position.z = global_pose.getOrigin().z();
start.pose.orientation.x = global_pose.getRotation().x();
start.pose.orientation.y = global_pose.getRotation().y();
start.pose.orientation.z = global_pose.getRotation().z();
start.pose.orientation.w = global_pose.getRotation().w();
makePlan(start, *goal, path);
}
void ExploreFrontier::findFrontiers(Costmap2DROS& costmap_) {
frontiers_.clear();
Costmap2D costmap;
costmap_.getCostmapCopy(costmap);
int idx;
int w = costmap.getSizeInCellsX();
int h = costmap.getSizeInCellsY();
int size = (w * h);
int pts = 0;
map_.info.width = w;
map_.info.height = h;
map_.set_data_size(size);
map_.info.resolution = costmap.getResolution();
map_.info.origin.position.x = costmap.getOriginX();
map_.info.origin.position.y = costmap.getOriginY();
// Find all frontiers (open cells next to unknown cells).
const unsigned char* map = costmap.getCharMap();
for (idx = 0; idx < size; idx++) {
//get the world point for the index
unsigned int mx, my;
costmap.indexToCells(idx, mx, my);
geometry_msgs::Point p;
costmap.mapToWorld(mx, my, p.x, p.y);
//check if the point has valid potential and is next to unknown space
//bool valid_point = planner_->validPointPotential(p);
//bool valid_point = planner_->computePotential(p) && planner_->validPointPotential(p);
//bool valid_point = (map[idx] < LETHAL_OBSTACLE);
//bool valid_point = (map[idx] < INSCRIBED_INFLATED_OBSTACLE );
bool valid_point = (map[idx] == FREE_SPACE);
if ((valid_point && map) &&
(((idx+1 < size) && (map[idx+1] == NO_INFORMATION)) ||
((idx-1 >= 0) && (map[idx-1] == NO_INFORMATION)) ||
((idx+w < size) && (map[idx+w] == NO_INFORMATION)) ||
((idx-w >= 0) && (map[idx-w] == NO_INFORMATION))))
{
map_.data[idx] = -128;
//ROS_INFO("Candidate Point %d.", pts++ );
} else {
map_.data[idx] = -127;
}
}
// Clean up frontiers detected on separate rows of the map
// I don't know what this means -- Travis.
idx = map_.info.height - 1;
for (unsigned int y=0; y < map_.info.width; y++) {
map_.data[idx] = -127;
idx += map_.info.height;
}
// Group adjoining map_ pixels
int segment_id = 127;
std::vector< std::vector<FrontierPoint> > segments;
for (int i = 0; i < size; i++) {
if (map_.data[i] == -128) {
std::vector<int> neighbors, candidates;
std::vector<FrontierPoint> segment;
neighbors.push_back(i);
int points_in_seg = 0;
unsigned int mx, my;
geometry_msgs::Point p_init, p;
costmap.indexToCells(i, mx, my);
costmap.mapToWorld(mx, my, p_init.x, p_init.y);
// claim all neighbors
while (neighbors.size() > 0) {
int idx = neighbors.back();
neighbors.pop_back();
btVector3 tot(0,0,0);
int c = 0;
if ((idx+1 < size) && (map[idx+1] == NO_INFORMATION)) {
tot += btVector3(1,0,0);
c++;
}
if ((idx-1 >= 0) && (map[idx-1] == NO_INFORMATION)) {
tot += btVector3(-1,0,0);
c++;
}
if ((idx+w < size) && (map[idx+w] == NO_INFORMATION)) {
tot += btVector3(0,1,0);
c++;
}
if ((idx-w >= 0) && (map[idx-w] == NO_INFORMATION)) {
tot += btVector3(0,-1,0);
c++;
}
assert(c > 0);
// Only adjust the map and add idx to segment when its near enough to start point.
// This should prevent greedy approach where all cells belong to one frontier!
costmap.indexToCells(idx, mx, my);
costmap.mapToWorld(mx, my, p.x, p.y);
float dist;
dist = sqrt( pow( p.x - p_init.x, 2 ) + pow( p.y - p_init.y, 2 ));
if ( dist <= 0.8 ){
map_.data[idx] = segment_id; // This used to be up before "assert" block above.
points_in_seg += 1;
//ROS_INFO( "Dist to start cell: %3.2f", dist );
segment.push_back(FrontierPoint(idx, tot / c));
// consider 8 neighborhood
if (((idx-1)>0) && (map_.data[idx-1] == -128))
neighbors.push_back(idx-1);
if (((idx+1)<size) && (map_.data[idx+1] == -128))
neighbors.push_back(idx+1);
if (((idx-map_.info.width)>0) && (map_.data[idx-map_.info.width] == -128))
neighbors.push_back(idx-map_.info.width);
if (((idx-map_.info.width+1)>0) && (map_.data[idx-map_.info.width+1] == -128))
neighbors.push_back(idx-map_.info.width+1);
if (((idx-map_.info.width-1)>0) && (map_.data[idx-map_.info.width-1] == -128))
neighbors.push_back(idx-map_.info.width-1);
if (((idx+(int)map_.info.width)<size) && (map_.data[idx+map_.info.width] == -128))
neighbors.push_back(idx+map_.info.width);
if (((idx+(int)map_.info.width+1)<size) && (map_.data[idx+map_.info.width+1] == -128))
neighbors.push_back(idx+map_.info.width+1);
if (((idx+(int)map_.info.width-1)<size) && (map_.data[idx+map_.info.width-1] == -128))
neighbors.push_back(idx+map_.info.width-1);
}
}
segments.push_back(segment);
ROS_INFO( "Segment %d has %d costmap cells", segment_id, points_in_seg );
segment_id--;
if (segment_id < -127)
break;
}
}
int num_segments = 127 - segment_id;
ROS_INFO("Segments: %d", num_segments );
if (num_segments <= 0)
return;
for (unsigned int i=0; i < segments.size(); i++) {
Frontier frontier;
std::vector<FrontierPoint>& segment = segments[i];
uint size = segment.size();
//we want to make sure that the frontier is big enough for the robot to fit through
// This seems like a goofy heuristic rather than fact. What happens if we don't do this...?
if (size * costmap.getResolution() < costmap.getInscribedRadius()){
ROS_INFO( "Discarding segment... too small?" );
//continue;
}
float x = 0, y = 0;
btVector3 d(0,0,0);
for (uint j=0; j<size; j++) {
d += segment[j].d;
int idx = segment[j].idx;
x += (idx % map_.info.width);
y += (idx / map_.info.width);
// x = (idx % map_.info.width);
// y = (idx / map_.info.width);
}
d = d / size;
frontier.pose.position.x = map_.info.origin.position.x + map_.info.resolution * (x / size);
frontier.pose.position.y = map_.info.origin.position.y + map_.info.resolution * (y / size);
// frontier.pose.position.x = map_.info.origin.position.x + map_.info.resolution * (x);
// frontier.pose.position.y = map_.info.origin.position.y + map_.info.resolution * (y);
frontier.pose.position.z = 0.0;
frontier.pose.orientation = tf::createQuaternionMsgFromYaw(btAtan2(d.y(), d.x()));
frontier.size = size;
geometry_msgs::Point p;
p.x = map_.info.origin.position.x + map_.info.resolution * (x); // frontier.pose.position
p.y = map_.info.origin.position.y + map_.info.resolution * (y);
if (!planner_->validPointPotential(p)){
ROS_INFO( "Discarding segment... can't reach?" );
//continue;
}
frontiers_.push_back(frontier);
}
}
bool ExploreFrontier::getExplorationGoals(Costmap2DROS& costmap, geometry_msgs::Point start, navfn::NavfnROS* planner, std::vector<geometry_msgs::Pose>& goals, double potential_scale, double orientation_scale, double gain_scale)
{
planner->computePotential(start);
planner_ = planner;
costmapResolution_ = costmap.getResolution();
findFrontiers(costmap);
if (frontiers_.size() == 0){
return false;
}
//we'll make sure that we set goals for the frontier at least the circumscribed
//radius away from unknown space
double goal_stepback = costmap.getCircumscribedRadius();
WeightedFrontier goal;
std::vector<WeightedFrontier> weightedFrontiers;
weightedFrontiers.reserve(frontiers_.size());
for (uint i=0; i < frontiers_.size(); i++) {
Frontier& frontier = frontiers_[i];
WeightedFrontier weightedFrontier;
weightedFrontier.frontier = frontier;
tf::Quaternion bt;
tf::quaternionMsgToTF(frontier.pose.orientation, bt);
double distance = 0.0;
//we'll walk back along the potential function generated by the planner from the frontier point at least the inscribed radius
while(distance < goal_stepback){
geometry_msgs::Point check_point = frontier.pose.position;
check_point.x -= costmapResolution_;
check_point.y -= costmapResolution_;
double best_potential = planner->getPointPotential(check_point);
geometry_msgs::Point best_point = check_point;
//look at the neighbors of the current point to find the one with the lowest potential
for(unsigned int i = 0; i < 3; ++i){
for(unsigned int j = 0; j < 3; ++j){
check_point.x += costmapResolution_;
double potential = planner->getPointPotential(check_point);
//check if the potential is better, make sure that we don't check the frontier point itself
if(potential < best_potential && !(i == 1 && j == 1)){
best_potential = potential;
best_point = check_point;
}
}
check_point.x = frontier.pose.position.x - costmapResolution_;
check_point.y += costmapResolution_;
}
//update the frontier position and add to the distance traveled
frontier.pose.position.x = best_point.x;
frontier.pose.position.y = best_point.y;
distance += costmapResolution_;
}
//create a line using the vector we stored in the frontier
//Line l(Point(frontier.pose.position.x, frontier.pose.position.y, frontier.pose.position.z), bt.getAngle());
//step back the inscribed radius along that line to find a goal point
//Point t = l.eval(goal_stepback);
weightedFrontier.frontier.pose.position.x = frontier.pose.position.x;
weightedFrontier.frontier.pose.position.y = frontier.pose.position.y;
weightedFrontier.frontier.pose.position.z = frontier.pose.position.z;
tf::Stamped<tf::Pose> robot_pose;
costmap.getRobotPose(robot_pose);
//compute the cost of the frontier
weightedFrontier.cost = potential_scale * getFrontierCost(weightedFrontier.frontier) + orientation_scale * getOrientationChange(weightedFrontier.frontier, robot_pose) - gain_scale * getFrontierGain(weightedFrontier.frontier, costmapResolution_);
weightedFrontiers.push_back(weightedFrontier);
}
goals.clear();
goals.reserve(weightedFrontiers.size());
std::sort(weightedFrontiers.begin(), weightedFrontiers.end());
for (uint i = 0; i < weightedFrontiers.size(); i++) {
goals.push_back(weightedFrontiers[i].frontier.pose);
}
return (goals.size() > 0);
}
