Rafiki Front Bumber

How to use the Rafiki Front Bumber robot skill

This is the front bumper sensor plugin for Rafiki from Cochran Robotics. A Cochran Robotics sub-controller for a parking sensor must be used with this control, which is part of Rafiki.

THIS IS IN BETA

4 different proximity sensors are on the front of the Rafiki (left, left front, right front, and right). This plugin converts the information provided from these sensors into variables in ARC. If the object is close to a particular direction, the motor controller will not allow the robot to move or turn in that direction. ARC is connected to the bumper subsystem controller via serial. This sensor is also used in the SLAM module along with the LIDAR sensor and drop off sensors.

A serial command of "Q0" will return the name of the sensor. There will be another plugin that you will be able to use to identify all of the Rafiki subsystem controller boards. For now, you will have to identify this controller and specify the name of the COM port in the config section of this plugin. The user can identify which port is used for the front bumper by sending a Q0 serial command to the controller com port which needs to be set to 9600, N, 8, 1 which is the default configuration in Windows. This can be done via an Arduino serial monitor or via the Serial Terminal (PC) control in the General list of controls.

This plugin will update 4 variables. You can use these values to then do things withing ARC.  They are called $Rafiki_Bumper_Left $Rafiki_Bumper_Front_Left $Rafiki_Bumper_Front_Right $Rafiki_Bumper_Right

The values will be either Clear Object_Detected Object_Close

The Drive Motor controller is hard wired to this controller. If an object is close to Rafiki, the drive motor controller will refuse commands sent to it to turn or move toward that direction. The Drive motor controller is also tied into the drop-off sensor motor controller. If a drop-off is detected by any of the front 3 sensors, Rafiki's drive motor controller will refuse commands to move forward. The same goes for the back drop-off sensors. Each of these subsystems runs off of its own 16 MHz controller, which is responsible for monitoring specifically one system. This allows any drop-offs or objects that are close to being monitored at the same time. By having these connections to the motor controller we are able to stop Rafiki and then alert them that there was an issue. This allows a much faster and more reliable response than sending a command to ARC. and then having ARC send a command to the motor controller to stop. Also, it is possible for ARC to miss a piece of information. In this event, this missed piece of information could cause damage to someone or to Rafiki itself.

You will run this plugin via a script. Here is an example script

:TopOfLoop
ControlCommand("Rafiki Front Bumber", Start)
sleep(2000)
GoTo(TopOfLoop)