Colony » Colony Scout

/**

 * The code in this package was developed using the structure of Willow

 * Garage's turtlesim package.  It was modified by the CMU Robotics Club

 * to be used as a simulator for the Colony Scout robot.

 *

 * All redistribution of this code is limited to the terms of Willow Garage's

 * licensing terms, as well as under permission from the CMU Robotics Club.

 * 

 * Copyright (c) 2011 Colony Project

 * 

 * Permission is hereby granted, free of charge, to any person

 * obtaining a copy of this software and associated documentation

 * files (the "Software"), to deal in the Software without

 * restriction, including without limitation the rights to use,

 * copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following

 * conditions:

 * 

 * The above copyright notice and this permission notice shall be

 * included in all copies or substantial portions of the Software.

 * 

 * Copyright (c) 2009, Willow Garage, Inc.

 * All rights reserved.

 * 

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 * 

 *    Redistributions of source code must retain the above copyright

 *       notice, this list of conditions and the following disclaimer.

 *    Redistributions in binary form must reproduce the above copyright

 *       notice, this list of conditions and the following disclaimer in the

 *       documentation and/or other materials provided with the distribution.

 *    Neither the name of the Willow Garage, Inc. nor the names of its

 *       contributors may be used to endorse or promote products derived from

 *       this software without specific prior written permission.

 * 

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

 * OTHER DEALINGS IN THE SOFTWARE.

 */

#include "scout.h"

#include <wx/wx.h>

#define DEFAULT_PEN_R 0xb3

#define DEFAULT_PEN_G 0xb8

#define DEFAULT_PEN_B 0xff

using namespace std;

namespace scoutsim

{

    Scout::Scout(const ros::NodeHandle& nh,

                 const wxImage& scout_image,

                 const Vector2& pos,

                 wxBitmap *path_bitmap,

                 float orient)

        : path_bitmap(path_bitmap)

          , sonar_on(sonar_on)

          , node (nh)

          , scout_image(scout_image)

          , pos(pos)

          , orient(orient)

          , motor_fl_speed(0)

          , motor_fr_speed(0)

          , motor_bl_speed(0)

          , motor_br_speed(0)

          , fl_ticks(0)

          , fr_ticks(0)

          , bl_ticks(0)

          , br_ticks(0)

          , pen_on(true)

          , pen(wxColour(DEFAULT_PEN_R, DEFAULT_PEN_G, DEFAULT_PEN_B))

    {

        pen.SetWidth(3);

        scout = wxBitmap(scout_image);

        motors_sub = node.subscribe("set_motors", 1, &Scout::setMotors, this);

        pose_pub = node.advertise<Pose>("pose", 1);

        color_pub = node.advertise<Color>("color_sensor", 1);

        sonar_pub = node.advertise<sonar::sonar_distance>("sonar_distance", 1);

        set_pen_srv = node.advertiseService("set_pen",

                                            &Scout::setPenCallback,

                                            this);

        query_encoders_srv =

            node.advertiseService("query_encoders",

                                  &Scout::query_encoders_callback,

                                  this);

        query_linesensor_srv =

            node.advertiseService("query_linesensor",

                                  &Scout::query_linesensor_callback,

                                  this);

        for (unsigned int i = 0; i < NUM_LINESENSORS; i++)

        {

            linesensor_readings.push_back(0);

        }

        // Initialize sonar

        sonar_position = 0;

        sonar_stop_l = 0;

        sonar_stop_r = 23;

        sonar_direction = 1;

        sonar_tick_time = ros::Duration(scoutsim::SONAR_HALF_SPIN_TIME / 24.0);

    }

    float Scout::absolute_to_mps(int absolute_speed)

    {

        return ((float) absolute_speed) * MAX_SPEED_MPS / MAX_ABSOLUTE_SPEED;

    }

    /**

     * A callback function that sets velocity based on a set_motors

     * request.

     * @todo Use "callback" in all callback function names? Or remove?

     */

    void Scout::setMotors(const motors::set_motors::ConstPtr& msg)

    {

        last_command_time = ros::WallTime::now();

        if(msg->fl_set)

        {

            motor_fl_speed = absolute_to_mps(msg->fl_speed);

        }

        if(msg->fr_set)

        {

            motor_fr_speed = absolute_to_mps(msg->fr_speed);

        }

        if(msg->bl_set)

        {

            motor_bl_speed = absolute_to_mps(msg->bl_speed);

        }

        if(msg->br_set)

        {

            motor_br_speed = absolute_to_mps(msg->br_speed);

        }

    }

    bool Scout::setPenCallback(scoutsim::SetPen::Request& req,

                               scoutsim::SetPen::Response&)

    {

        pen_on = !req.off;

        if (req.off)

        {

            return true;

        }

        wxPen pen(wxColour(req.r, req.g, req.b));

        if (req.width != 0)

        {

            pen.SetWidth(req.width);

        }

        pen = pen;

        return true;

    }

    bool Scout::query_encoders_callback(encoders::query_encoders::Request&,

                                        encoders::query_encoders::Response& res)

    {

        res.fl_distance = fl_ticks;

        res.fr_distance = fr_ticks;

        res.bl_distance = bl_ticks;

        res.br_distance = br_ticks;

        return true;

    }

    bool Scout::query_linesensor_callback(linesensor::query_linesensor::Request&,

                                          linesensor::query_linesensor::Response& res)

    {

        res.readings = linesensor_readings;

        return true;

    }

    // Scale to linesensor value

    unsigned int Scout::rgb_to_grey(unsigned char r,

                                    unsigned char g,

                                    unsigned char b)

    {

        // Should be 0 to 255

        unsigned int grey = ((unsigned int) r + (unsigned int) g + (unsigned int) b) / 3;

        /// @todo Convert to the proper range

        return 255 - grey;

    }

    unsigned int Scout::trace_sonar(const wxImage& walls_image, int x, int y,

                                    double robot_theta, int sonar_pos,

                                    wxMemoryDC& sonar_dc, bool sonar_on)

    {

        double angle = robot_theta + (PI * ((float) sonar_pos) / 24.0) - PI / 2;

        unsigned int d = 0;

        unsigned int reading = 0;

        int d_x = 0;

        int d_y = 0;

        do

        {

            d_x = x + (int) floor(d * cos(angle));

            d_y = y + (int) floor(d * sin(angle));

            // Out of image boundary

            if (d_x < 0 || d_x >= walls_image.GetWidth() ||

                d_y < 0 || d_y >= walls_image.GetHeight())

            {

                return d;

            }

            // Max range

            if (d > scoutsim::SONAR_MAX_RANGE)

            {

                return d;

            }

            // Get the sonar reading at the current position of the sonar

            unsigned char r = walls_image.GetRed(d_x, d_y);

            unsigned char g = walls_image.GetGreen(d_x, d_y);

            unsigned char b = walls_image.GetBlue(d_x, d_y);

            reading = rgb_to_grey(r, g, b);

            d++;

        }

        /// @todo Consider using different cutoffs for different features

        while (reading < 128); /// @todo Get rid of hardcoded stuff like this

        if(sonar_on)

        {       

            if(isFront)

            {

                // draw a circle at the wall_x, wall_y where reading > 128

                sonar_dc.SelectObject(*path_bitmap);

                sonar_dc.SetBrush(*wxRED_BRUSH); //old value

                sonar_dc.DrawCircle(wxPoint(old_front_dx,old_front_dy), 2);

                old_front_dx = d_x;

                old_front_dy = d_y;

            }

            else

            {

                // draw a circle at the wall_x, wall_y where reading > 128

                sonar_dc.SelectObject(*path_bitmap);

                sonar_dc.SetBrush(*wxRED_BRUSH); //old value

                sonar_dc.DrawCircle(wxPoint(old_back_dx,old_back_dy), 2);

                old_back_dx = d_x;

                old_back_dy = d_y;

            }

            sonar_dc.SetBrush(*wxGREEN_BRUSH);  //newest value

            sonar_dc.DrawCircle( wxPoint(d_x,d_y), 2);

            if (isFront) //for some reason isFront = (!isFront) is not working

            {

                isFront = FALSE;

            }

            else

            {

                isFront = TRUE;        

            }

        }

        return d;

    }

    // x and y is current position of the sonar

    void Scout::update_sonar(const wxImage& walls_image, int x, int y,

                             double robot_theta,wxMemoryDC& sonar_dc, bool sonar_on)

    {

        // Only rotate the sonar at the correct rate.

        if (ros::Time::now() - last_sonar_time < sonar_tick_time)

        {

            return;

        }

        last_sonar_time = ros::Time::now();

        unsigned int d_front = trace_sonar(walls_image, x, y, robot_theta,

                                           sonar_position,sonar_dc, sonar_on);

        unsigned int d_back = trace_sonar(walls_image, x, y, robot_theta,

                                          sonar_position + 24,sonar_dc, sonar_on);

        // Publish

        sonar::sonar_distance msg;

        msg.pos = sonar_position;

        msg.distance0 = d_front;

        msg.distance1 = d_back;

        sonar_pub.publish(msg);

        // Update the sonar rotation

        if (sonar_position + sonar_direction <= sonar_stop_r &&

            sonar_position + sonar_direction >= sonar_stop_l)

        {

            sonar_position = sonar_position + sonar_direction;

        }

        else

        {

            sonar_direction = -sonar_direction;

        }

    }

    void Scout::update_linesensor(const wxImage& lines_image, int x, int y,

                                  double robot_theta)

    {

        linesensor_readings.clear();

        double spacing = scout_image.GetWidth() / (NUM_LINESENSORS - 1);

        for (int s = 0; s < NUM_LINESENSORS; s++)

        {

            double offset = -(scout_image.GetWidth() / 2) + s * spacing;

            int sensor_x = (int) (x - LNSNSR_D * cos(robot_theta) -

                                  offset * sin(robot_theta));

            int sensor_y = (int) (y + LNSNSR_D * sin(robot_theta) -

                                  offset * cos(robot_theta));

            unsigned char r = lines_image.GetRed(sensor_x, sensor_y);

            unsigned char g = lines_image.GetGreen(sensor_x, sensor_y);

            unsigned char b = lines_image.GetBlue(sensor_x, sensor_y);

            unsigned int reading = rgb_to_grey(r, g, b);

            linesensor_readings.push_back(reading);

        }

    }

    /// Sends back the position of this scout so scoutsim can save

    /// the world state

    geometry_msgs::Pose2D Scout::update(double dt, wxMemoryDC& path_dc,

                                        wxMemoryDC& sonar_dc,

                                        bool sonar_on,

                                        const wxImage& path_image,

                                        const wxImage& lines_image,

                                        const wxImage& walls_image,

                                        wxColour background_color,

                                        wxColour sonar_color,

                                        world_state state)

    {

        // Assume that the two motors on the same side will be set to

        // roughly the same speed. Does not account for slip conditions

        // when they are set to different speeds.

        float l_speed = (float (motor_fl_speed + motor_bl_speed)) / 2;

        float r_speed = (float (motor_fr_speed + motor_br_speed)) / 2;

        // Find linear and angular movement in m

        float lin_dist = SCOUTSIM_REFRESH_RATE * (l_speed + r_speed) / 2;

        float ang_dist = SCOUTSIM_REFRESH_RATE * (r_speed - l_speed);

        Vector2 old_pos = pos;

        // Update encoders

        fl_ticks += (unsigned int) (motor_fl_speed * SCOUTSIM_REFRESH_RATE *

                                    ENCODER_TICKS_PER_METER);

        fr_ticks += (unsigned int) (motor_fr_speed * SCOUTSIM_REFRESH_RATE *

                                    ENCODER_TICKS_PER_METER);

        bl_ticks += (unsigned int) (motor_bl_speed * SCOUTSIM_REFRESH_RATE *

                                    ENCODER_TICKS_PER_METER);

        br_ticks += (unsigned int) (motor_br_speed * SCOUTSIM_REFRESH_RATE *

                                    ENCODER_TICKS_PER_METER);

        orient = fmod((float) (orient + ang_dist), (float) (2.0 * PI));

        // Multiply by dt, the time passed (SCOUTSIM_REFRESH_RATE)

        pos.x += sin(orient + PI/2.0) * lin_dist;

        pos.y += cos(orient + PI/2.0) * lin_dist;

        // Clamp to screen size

        if (pos.x < 0 || pos.x >= state.canvas_width

                || pos.y < 0 || pos.y >= state.canvas_height)

        {

            ROS_WARN("I hit the wall! (Clamping from [x=%f, y=%f])", pos.x, pos.y);

        }

        pos.x = min(max(pos.x, 0.0f), state.canvas_width);

        pos.y = min(max(pos.y, 0.0f), state.canvas_height);

        int canvas_x = pos.x * PIX_PER_METER;

        int canvas_y = pos.y * PIX_PER_METER;

        {

            wxImage rotated_image =

                scout_image.Rotate(orient - PI/2.0,

                                   wxPoint(scout_image.GetWidth() / 2,

                                           scout_image.GetHeight() / 2),

                                   false);

            for (int y = 0; y < rotated_image.GetHeight(); ++y)

            {

                for (int x = 0; x < rotated_image.GetWidth(); ++x)

                {

                    if (rotated_image.GetRed(x, y) == 255

                            && rotated_image.GetBlue(x, y) == 255

                            && rotated_image.GetGreen(x, y) == 255)

                    {

                        rotated_image.SetAlpha(x, y, 0);

                    }

                }

            }

            scout = wxBitmap(rotated_image);

        }

        Pose p;

        p.x = pos.x;

        p.y = state.canvas_height - pos.y;

        p.theta = orient;

        p.linear_velocity = l_speed;

        p.angular_velocity = r_speed;

        pose_pub.publish(p);

        update_linesensor(lines_image, canvas_x, canvas_y, p.theta);

        update_sonar(walls_image,

                     canvas_x + scoutsim::SCOUT_SONAR_X,

                     canvas_y + scoutsim::SCOUT_SONAR_Y,

                     p.theta,sonar_dc,sonar_on);

        // Figure out (and publish) the color underneath the scout

        {

            //wxSize scout_size = wxSize(scout.GetWidth(), scout.GetHeight());

            Color color;

            color.r = path_image.GetRed(canvas_x, canvas_y);

            color.g = path_image.GetGreen(canvas_x, canvas_y);

            color.b = path_image.GetBlue(canvas_x, canvas_y);

            color_pub.publish(color);

        }

        ROS_DEBUG("[%s]: pos_x: %f pos_y: %f theta: %f",

                  node.getNamespace().c_str(), pos.x, pos.y, orient);

        if (pen_on)

        {

            if (pos != old_pos)

            {

                path_dc.SelectObject(*path_bitmap);

                path_dc.SetPen(pen);

                path_dc.DrawLine(pos.x * PIX_PER_METER, pos.y * PIX_PER_METER,

                                 old_pos.x * PIX_PER_METER, old_pos.y * PIX_PER_METER);

            }

        }

        geometry_msgs::Pose2D my_pose;

        my_pose.x = pos.x;

        my_pose.y = pos.y;

        my_pose.theta = orient;

        return my_pose;

    }

    void Scout::paint(wxDC& dc)

    {

        wxSize scout_size = wxSize(scout.GetWidth(), scout.GetHeight());

        dc.DrawBitmap(scout, pos.x * PIX_PER_METER - (scout_size.GetWidth() / 2),

                      pos.y * PIX_PER_METER - (scout_size.GetHeight() / 2), true);

    }

}