This example is similar to Click-and-drive but includes a
PathPlanner to find a path around an obstacle.
#!/usr/bin/env python3 from nicegui import ui from nicegui.events import SceneClickEventArguments from rosys.automation import Automator from rosys.driving import Driver, Odometer, robot_object from rosys.geometry import Point, Pose, Prism from rosys.hardware import RobotSimulation, WheelsSimulation from rosys.pathplanning import Obstacle, PathPlanner, obstacle_object, path_object shape = Prism.default_robot_shape() path_planner = PathPlanner(shape) path_planner.restore = lambda _: None # NOTE: disable persistence path_planner.obstacles['0'] = Obstacle(id='0', outline=[Point(x=3, y=0), Point(x=0, y=3), Point(x=3, y=3)]) wheels = WheelsSimulation() robot = RobotSimulation([wheels]) odometer = Odometer(wheels) driver = Driver(wheels, odometer) automator = Automator(None, on_interrupt=wheels.stop) async def handle_click(e: SceneClickEventArguments): for hit in e.hits: if hit.object_id == 'ground': goal = Pose(x=hit.x, y=hit.y, yaw=odometer.prediction.direction(Point(x=hit.x, y=hit.y))) path = await path_planner.search(start=odometer.prediction, goal=goal) path3d.update(path) automator.start(driver.drive_path(path)) with ui.scene(on_click=handle_click, width=600): robot_object(shape, odometer) obstacle_object(path_planner) path3d = path_object() ui.label('click into the scene to drive the robot') ui.run(title='RoSys')
When following a path, a "carrot" is dragged along a spline and the robot follows it like a donkey. Additionally, there is a virtual "hook" attached to the robot, which is pulled towards the carrot.
There are three parameters:
hook_offset: How far from the wheel axis (i.e. the coordinate center of the robot) is the hook, which is pulled towards the carrot.
carrot_offset: How far ahead of the carrot is the robot pulled. This parameter is necessary in order to have the hook pulled a bit further, even though the carrot already reached the end of the spline.
carrot_distance: How long is the "thread" between hook and carrot (or the offset point ahead of the carrot, respectively).
In the following illustration these points are depicted as spheres: the coordinate center of the robot (blue, small), the hook (blue, large), carrot (orange, small), offset point ahead of the carrot (orange, large).
You can display a wire frame version of the robot by passing
debug=true to the
drive_spline has an optional argument
It turns the hook 180 degrees to the back of the robot, while preserving the distance
hook_offset to the robot's coordinate center.
This allows the robot to drive backwards to a point behind it instead of turning around and approaching it forwards.
A more complex example can be found in the RoSys GitHub repository. There you can create new obstacles and choose between straight driving or navigation.