Rexctl: CLI application to control Rex

Rexctl is a CLI application to bootstrap and control Rex. The purpose of this repository is to provide an application to implement the knowledge tranfer of the control policies pre-trained with rex-gym.

Prerequisites

This code is designed to run on UNIX machines and was tested on the Nvidia Jetson Nano. Check out the Wiki for more information on the hardware setup.

Rexctl starts a web server using uwsgi and Flask. In order to allow operations on the board, you need to give permissions to the www-data user:

sudo usermod -a -G gpio www-data
sudo usermod -a -G i2c www-data

Installation

Install this package system-wide.

From the root of the project:

sudo -H pip3 install .

Commands

The entry point command is rexctl.

Command	Description
init	Start the web server and initialise the hardware. This is the first command you need to run in order to bootstrap the robot.
status	Get the status of all the daemons.
exec	Start a task. Check the /exec endpoint for more info.
log	Get the execution logs.
stop-all	Kill all the active tasks.
debug-pose	Set the debug pose. This is used to check the servos alignment.
calibration	Get the BNO055 calibration status.
store-calibration	Persist the current BNO055 calibration.

API

Rexctl uses nginx to create a local DNS entry to map the device name you have setup during the bootstrap to localhost.

E.g. using rex you will able to access the APIs as follows:

http://rex/

Endpoints

Start a Task

Start a new Task. Currently, the following tasks are available:

Task	Parameters	Description
set_position	* pose_id: (str) The pose name. Check the available poses here.	Set a position setting the servos angles.
set_gait	* action_id: (str) The gait name. Check the available poses here	Start a gait running a pre-trained control policy.

URL : /exec

Method : POST

Body

Provide the task name and the required arguments.

{ 
  "daemon_id": "str",
  "command_id": "str",
  "command_args": {
    "arg_0": "value0",
    ...
  }
} 

Examples

Set a standard position.

{
  "daemon_id": "motion",
  "command_id": "set_position",
  "command_args": {
    "pose_id": "stand_low"
  }
}

Start a pre-trained gait.

{
  "daemon_id": "motion",
  "command_id": "set_gait",
  "command_args": {
    "action_id": "walk",
    "simulation": true
  }
}

Response

Code : 200 OK

Get the robot status

Get the current status.

URL : /status

Method : GET

Response

Code : 200 OK

{
  "motion": "active",
  "perception": "active"
}

Stop all the tasks.

Kill all the running tasks.

URL : /stop_all

Method : GET

Response

Code : 200 OK

{
  "200": "command sent."
}

Get the BNO055 calibration.

Retrieve the current calibration status.

URL : /get_calibration

Method : GET

Response

Code : 200 OK

{
  "system": "int",
  "gyroscope": "int", 
  "accelerometer": "int", 
  "magnetometer": "int", 
  "mode": "int"
}

Store BNO055 calibration.

Persist the current BNO055 calibration data. This data will be loaded at every startup.

URL : /store_calibration

Method : GET

Response

Code : 200 OK

{
  "200": "command sent."
}