Overview

The communication with CoppeliaSim is handled by vrep-api-wrapper which is required by this project.

The application launched by the user is mc_vrep with an optional configuration file for the controller (which controller to use, environment to load, etc...).

The simulation is entirely driven by mc_vrep, with the following timeline for each time step of the simulation:

Get joints/sensors data from CoppeliaSim
Compute the control
Send the control result to CoppeliaSim

ATM (2016/08/29), it is possible to communicate with mc_vrep via a CLI but not more.

Current limitations (last update: 2016/08/29)

The scene has to be loaded manually in CoppeliaSim and mc_vrep assumes three things, warnings are emitted if these assumptions are not respected:

The robot controlled by mc_vrep is loaded in the scene and the joints' names in CoppeliaSim match those in the URDF loaded by mc_rtc;
The robot's model in CoppeliaSim has a base;
The force sensors' names in CoppeliaSim match the force sensors' names in mc_rtc;

Installation guide

mc_rtc

Follow mc_rtc installation guide for details on installation.

vrep-api-wrapper

Please refer to the project's page for detailed instructions on the installation. You will have to install CoppeliaSim by yourself.

mc_vrep

Once you have mc_rtc and vrep-api-wrapper on your system you can build and install mc_vrep easily, using cmake:

mkdir build
cd build
cmake ../ -DCMAKE_BUILD_TYPE=RelWithDebInfo
make
sudo make install

Usage

Load a CoppeliaSim simulation with the robot you wish to control
Configure mc_rtc accordingly (controller and robot selection)
Run the mc_vrep command

Inside mc_rtc GUI you can interact with the simulation:

stop it;
enable/disable step by step mode;
when step by step mode is enabled you can also step multiple times into the simulation;

Running with multiple robots

mc_vrep supports multiple robots, to enable it add the following entry to your mc_rtc.yaml configuration:

VREP:
  Extras:
    - index: 1
      suffix: "#0"
    - index: 2
      suffix: "#1"

This will tell mc_vrep that robots with index 1 and 2 in your controller are also present in the CoppeliaSim scene and can be controlled. Furthermore, the suffix is used by CoppeliaSim when multiple robots of the same type are inserted into the scene. In such cases, CoppeliaSim will append this suffix to every joints' and links' name in the simulated model so we need to tell mc_vrep what the suffix is.

Simulation settings

The VREP section accepts the following parameters related to the simulation:

SimulationTimestep: timestep of the physics engine in the V-REP simulation; by default, mc_vrep assumes this is equal to the controller timestep;
StepByStep: starts the simulation in step by step mode;
VelocityControl: use the velocity output of mc_rtc to control the robots (default: false);
TorqueControl: use the torque output of mc_rtc to control the robots (default: false);

When both VelocityControl and TorqueControl are false (i.e. in default mode) the robots are controlled via the position output of mc_rtc.

Connection options

The VREP section accepts the following parameters, they correspond to the default remote API setting for CoppeliaSim:

Host: which host to connect to for CoppeliaSim remote API (default: localhost)
Port: which port to connect to for CoppeliaSim remote API (default: 19997)
Timeout: timeout when attempting the connection in milliseconds (default: 3000)
WaitUntilConnected: wait until the API is connected (default: true)
DoNotReconnect: do not attempt to reconnect if the connection is lost (default: true)
CommThreadCycleInMs: Remote API thread cycle duration in ms (default: 1, must be > 0)

arntanguy / mc_vrep