public void move() {
    if (last_move_time == null || last_move_time.doubleValue() < world.time) {
      last_move_time = new Double(world.time);
      double max_dist, dist_right, dist_left, theta, x, y, dist_diff;
      double delta_theta, turn_radius, new_theta, new_x, new_y;
      Location location;
      Orientation orientation;

      orientation = orientation();
      location = location();

      max_dist = max_speed / world.ticks_per_second;
      dist_right = right_motor.output() * max_dist;
      dist_left = left_motor.output() * max_dist;
      theta = orientation.theta;
      x = location.x;
      y = location.y;
      old_location.x = x;
      old_location.y = y;
      dist_diff = dist_right - dist_left;

      //			System.out.println("dist_diff: " + dist_diff);

      delta_theta = dist_diff / wheel_base;
      if (Math.abs(dist_diff) < .0001) {
        turn_radius = 0.0;
      } else {
        turn_radius = (dist_right / delta_theta) - (wheel_base / 2);
      }

      //			System.out.println("turn_radius: " + turn_radius);

      new_theta = theta + delta_theta;
      if (turn_radius == 0.0) {

        //				System.out.println("turn_radius == 0");

        new_x = x + Math.cos(theta) * dist_left;
        new_y = y + Math.sin(theta) * dist_left;
      } else {

        //				System.out.println("new_theta= " + new_theta + " theta= " + theta);

        new_x = x + ((Math.sin(new_theta) - Math.sin(theta)) * turn_radius);
        new_y = y - ((Math.cos(new_theta) - Math.cos(theta)) * turn_radius);
      }
      orientation.theta = new_theta;
      location.x = new_x;
      location.y = new_y;

      maybe_fire_guns();
    }
  }