Software features for enhancing collaborative robots

When setting up a collaborative robot, users should be aware of software functions such as safety plane functions and programming standards that are designed to improve the robot's function and safety features on the plant floor.

By Lars Skovsgaard March 17, 2016

When setting up a collaborative robot (cobot) it is a good idea to have some advanced knowledge of the software functions that are available to use with it. The user should know whether the software is a proprietary system that needs to be coded by an expert in the robot manufacturer’s system. It could also be an ROS-Industrial open source system or maybe some combination of the two. Consider these five functions designed to help and enhance cobots.

1. Safety plane functions.

Safety planes are designed to give the robot an area to run at normal speeds, but when the robot passes through a designated safety plane, it goes into reduced speed mode. This can be used where the robot has an area where it is preferable to reduce the robot’s motion and speed such as an area where a human operator is working. It is possible to set up these different safety planes, there can be some areas with normal speed and other areas with reduced speed.

These areas can also be configured so that they are triggered by external safety components like light sensors or laser scanners. This means that when a human triggers a signal the robot recognizes that the safety plane is operational and will automatically reduce its speed.

2. Ready-made widgets for controlling grippers.

Grippers can be controlled by a predefined command set like Modbus RTU commands, but other commands like EtherNet/IP, TCP/IP, DeviceNet, CANopen, EtherCAT can be used, as well.

In order to help and ease the programming load, widgets can be installed that include pre-defined template programs. These are designed to make control of the gripper much easier to include into the robot program. This includes the opening-closing range, as well as the speed control and the force control for the gripper.

3. Euromap 67 interface.

A cobot can be used for many different applications ranging from pick and place, packaging, process handling, machine tending and injection molding. In order to use a robot for tending these machines it is necessary to create an interface; so the robot only goes into the machine when the machine is idle and also so the machine does not start when the robot is inside the machine to pick or place an item. The Euromap 67 interface, which is an internationally recognized interface standard, is designed to help plug in and interconnect the robot and the application it is programmed for very quickly.

There are several benefits including a quick signal exchange, interconnection of emergency stop systems, and it is fast to create a program that interfaces with the application.

4. Force mode.

Some cobots have a built-in force mode, where it is possible to achieve force measurements in the range of:

  • Force precision ± 10 N
  • Torque precision ± 5 Nm
  • Position precision ± 5 mm
  • Orientation precision ± 0.5-deg.

This can be used in applications where a certain force is necessary when applied to the robot’s end effector, for example, in a polishing task where it is important to keep a set force pressure on the polishing tool towards the object being polished.

However, in applications where a much higher precision of the force is necessary; then an external force torque sensor can be mounted on the robot between the robot and end effector. This will provide measurements for the range:

  • Fx, Fy, Fz: ± 300 N
  • Mx, My, Mz: ± 30 N*m.

With Signal noise:

  • Fx, Fy: 0.80N
  • Fz: 0.5N
  • Mx, My: 0.01 N*m
  • Mz: 0.03 N*m.

5. Script and socket programming.

With a fast graphical user interface (GUI), the user can get started with robot programming right away construct a robot program within minutes.

However, if the robot task and robot cell requires the handling of a particularly complicated task which may include many external components, for example a vision system, or if the robot needs to exchange data with an external host system; then it is also possible to create a program for this. This might be important for advanced users or complex applications, but even for this a lot of examples and help can be found online.

Having available information, example programs, and a community of robot users, who are interested and willing to share their knowledge, is a huge plus for the integration and utilization of any robot cell. 

Robotiq

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Edited by Chris Vavra, production editor, Control Engineering, CFE Media, cvavra@cfemedia.com. See more Control Engineering robotics stories.

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