int main()
{
// Setup for random number generator
srand(time(NULL));
// Initialize our particle filter
ParticleFilter filter;
// Load occupancy map of wean hall and data from log
filter.readMap();
filter.loadMapImage();
filter.readLog();
// Draw initial particles
filter.drawParticles();
// Start the filter!
for (int i = 1; i < filter.timestamps.size(); i++) {
filter.motionModel(i);
filter.updateWeights(i);
filter.resampleParticles();
filter.visualize();
}
std::cout << "Done!\n";
}
int main() {
uWS::Hub h;
// Set up parameters here
double delta_t = 0.1; // Time elapsed between measurements [sec]
double sensor_range = 50; // Sensor range [m]
double sigma_pos[3] = {
0.3, 0.3,
0.01}; // GPS measurement uncertainty [x [m], y [m], theta [rad]]
double sigma_landmark[2] = {
0.3, 0.3}; // Landmark measurement uncertainty [x [m], y [m]]
// Read map data
Map map;
if (!read_map_data("../data/map_data.txt", map)) {
cout << "Error: Could not open map file" << endl;
return -1;
}
// Create particle filter
ParticleFilter pf;
h.onMessage([&pf, &map, &delta_t, &sensor_range, &sigma_pos,
&sigma_landmark](uWS::WebSocket<uWS::SERVER> ws, char *data,
size_t length, uWS::OpCode opCode) {
// "42" at the start of the message means there's a websocket message event.
// The 4 signifies a websocket message
// The 2 signifies a websocket event
if (length && length > 2 && data[0] == '4' && data[1] == '2') {
auto s = hasData(std::string(data));
if (s != "") {
auto j = json::parse(s);
std::string event = j[0].get<std::string>();
if (event == "telemetry") {
// j[1] is the data JSON object
if (!pf.initialized()) {
// Sense noisy position data from the simulator
double sense_x = std::stod(j[1]["sense_x"].get<std::string>());
double sense_y = std::stod(j[1]["sense_y"].get<std::string>());
double sense_theta =
std::stod(j[1]["sense_theta"].get<std::string>());
pf.init(sense_x, sense_y, sense_theta, sigma_pos);
} else {
// Predict the vehicle's next state from previous (noiseless
// control) data.
double previous_velocity =
std::stod(j[1]["previous_velocity"].get<std::string>());
double previous_yawrate =
std::stod(j[1]["previous_yawrate"].get<std::string>());
pf.prediction(delta_t, sigma_pos, previous_velocity,
previous_yawrate);
}
// receive noisy observation data from the simulator
// sense_observations in JSON format
// [{obs_x,obs_y},{obs_x,obs_y},...{obs_x,obs_y}]
vector<LandmarkObs> noisy_observations;
string sense_observations_x = j[1]["sense_observations_x"];
string sense_observations_y = j[1]["sense_observations_y"];
std::vector<float> x_sense;
std::istringstream iss_x(sense_observations_x);
std::copy(std::istream_iterator<float>(iss_x),
std::istream_iterator<float>(),
std::back_inserter(x_sense));
std::vector<float> y_sense;
std::istringstream iss_y(sense_observations_y);
std::copy(std::istream_iterator<float>(iss_y),
std::istream_iterator<float>(),
std::back_inserter(y_sense));
for (int i = 0; i < x_sense.size(); i++) {
LandmarkObs obs;
obs.x = x_sense[i];
obs.y = y_sense[i];
noisy_observations.push_back(obs);
}
// Update the weights and resample
pf.updateWeights(sensor_range, sigma_landmark, noisy_observations,
map);
pf.resample();
// Calculate and output the average weighted error of the particle
// filter over all time steps so far.
vector<Particle> particles = pf.particles;
int num_particles = particles.size();
double highest_weight = -1.0;
Particle best_particle;
double weight_sum = 0.0;
for (int i = 0; i < num_particles; ++i) {
if (particles[i].weight > highest_weight) {
highest_weight = particles[i].weight;
best_particle = particles[i];
}
weight_sum += particles[i].weight;
}
cout << "highest w " << highest_weight << endl;
cout << "average w " << weight_sum / num_particles << endl;
json msgJson;
msgJson["best_particle_x"] = best_particle.x;
msgJson["best_particle_y"] = best_particle.y;
msgJson["best_particle_theta"] = best_particle.theta;
// Optional message data used for debugging particle's sensing and
// associations
msgJson["best_particle_associations"] =
pf.getAssociations(best_particle);
msgJson["best_particle_sense_x"] = pf.getSenseX(best_particle);
msgJson["best_particle_sense_y"] = pf.getSenseY(best_particle);
auto msg = "42[\"best_particle\"," + msgJson.dump() + "]";
// std::cout << msg << std::endl;
ws.send(msg.data(), msg.length(), uWS::OpCode::TEXT);
}
} else {
std::string msg = "42[\"manual\",{}]";
ws.send(msg.data(), msg.length(), uWS::OpCode::TEXT);
}
}
});
// We don't need this since we're not using HTTP but if it's removed the
// program
// doesn't compile :-(
h.onHttpRequest([](uWS::HttpResponse *res, uWS::HttpRequest req, char *data,
size_t, size_t) {
const std::string s = "<h1>Hello world!</h1>";
if (req.getUrl().valueLength == 1) {
res->end(s.data(), s.length());
} else {
// i guess this should be done more gracefully?
res->end(nullptr, 0);
}
});
h.onConnection([&h](uWS::WebSocket<uWS::SERVER> ws, uWS::HttpRequest req) {
std::cout << "Connected!!!" << std::endl;
});
h.onDisconnection([&h](uWS::WebSocket<uWS::SERVER> ws, int code,
char *message, size_t length) {
ws.close();
std::cout << "Disconnected" << std::endl;
});
int port = 4567;
if (h.listen(port)) {
std::cout << "Listening to port " << port << std::endl;
} else {
std::cerr << "Failed to listen to port" << std::endl;
return -1;
}
h.run();
}
