Created Date: April 28, 2016

The conveyor tracking functionality adjusts robots paths to the motion of a conveyor.
Conveyor tracking for linear and circular conveyors is available from software version 1.8.

This example is based on setup on a CB3 controller.

Conveyor Tracking Setup:

Enable conveyor tracking in the installation tab. The first step is to enable conveyor tracking.

• Specify encoder type

There are two available encoder types: Incremental and Absolute.

Incremental encoders can be connected to digital inputs 0 to 3. Decoding of digital signals runs at 40kHz. Using a Quadrature encoder (requiring two inputs), the robot is able to determine the speed along with direction of the conveyor. If the direction of the conveyor is constant, a single input can be used, detecting either Rising, Falling, or Rise and Fall edges to determine the speed of the conveyor.

Absolute encoders can be used when connected through a MODBUS signal. This requires that a digital MODBUS input register is preconfigured.

• Specify conveyor type

There are two conveyor types: Linear and Circular

When a linear conveyor is selected, a line feature must be configured to determine the direction of the conveyor. The line feature should be parallel to the direction of the conveyor, and there should be a large distance between the two points defining the line feature. It is recommended to configure the line feature by placing the tool firmly against the side of the conveyor when teaching the two points. The field Ticks per meter is used as the number of ticks the encoder generates when the conveyor moves one meter.

Ticks per meter = ticks per revolution of encoder / (2π * radius of encoder disc)

When tracking a circular conveyor, the center point of the conveyor (circle) must be defined. The value of Ticks per revolution must be the number of ticks the encoder generates when the conveyor rotates one full revolution.

• Conveyor Tracking Wizard

When using a conveyor, the robot can be configured to track it’s movement. A program node is available for tracking a conveyor, Conveyor Tracking. When the Conveyor Tracking defined in the installation is configured correctly, a linear or circular conveyor can be tracked. The node can be added from the Wizard Program node under the Structure tab. While the program is executing under the Conveyor Tracking node, the robot will adjusts it’s movements to follow the conveyor. Other movements are allowed while tracking the conveyor, but are relative to the motion of the conveyor belt.

• Examples: E6B2-CWZ5B 2000P/R

In this example, an incremental encoder, E6B2-CWZ5B 2000P/R from OMRON is used. The direction of conveyor is constant thus a single digital input is used to determine the speed of the conveyor.

The digital signal of encoder is wired to digital input 0.

 The encoder with a disc can generate a linear movement of the conveyor shown as a picture above. The linear type of conveyor requires ticks per meter. The ticks per revolution of this encoder are 2000, and the radius of encoder disc is 32.428 mm, therefore the ticks per meter are 9816.

2000 / (2π * 0.032428) = 9816

The direction of conveyor can be configured as a line in features setup.

All parameters are configured in conveyor tracking setup.

In this example, the conveyor is powered on by the digital output 0 and the encoder digital signal is wired to digital input 0. Also, the trigger sensor is connected to the digital input 1 to detect the object.

A simple pick and place with conveyor tracking is programmed

Download sample program at the bottom of the page. File name is conveyor_tracking_sample.zip
Note: It is required to download and load this installation file as it contains the Conveyor Tracking setup