Robot Device Modules

Show the Device Modules Menu

 

4-Axis Cylindrical Robot Device Module

This robot module controls a cylindrical mechanism with four degrees of freedom. See Figure 1.

Module Specifications

Minimum V+ compatibility:  10.2

V+ License Requirements:  “Kinematics License”

If you install this module but do not have the above license, an “*Option not installed*” message will be displayed when you restart your system.

Device module name: CYL

Device module identification number: 13

This number is displayed with the robot serial and model number after the system boots up, and whenever the ID monitor command is issued.

Default startup message: “4-Axis Cylindrical Robot”

The startup message is displayed just after the system boots up.

Default joint configuration (for V+ 11.0 and higher):

Joint	Axis	Board/Channel
1	1 (base rotation)	1/1
2	2 (vertical stroke)	1/2
3	3 (horizontal stroke)	1/3
4	4 (roll)	1/4

With multiple robots, it will be necessary to correct the joint configuration from the SPEC program to avoid conflicts.

Robot Option Word

This module does not use any bits of the robot option word. You should leave its value at 0.

Axis Configuration

1. Joint 1 is a revolute axis that rotates about the world Z axis. A positive change in joint angle corresponds to a positive rotation about the world Z axis.  When joint 1 is positioned at zero degrees, joint 3 (the horizontal linear axis) will point along the world X axis.  When joint 1 is positioned at 90 degrees, joint 3 will point along the world Y axis.

2. Joint 2 is a linear axis that moves in the world Z direction.  A positive displacement of the joint moves the robot's tool in a positive world Z direction.  When joint 2 is set to its zero position, the height of joint 3 above the world X-Y plane is defined by a parameter described below.

3. Joint 3 is a horizontal linear axis.  When joint 1 is positioned at zero degrees, a positive change in joint 3 corresponds to extension of the joint in the direction of the positive world X axis.  When joint 3 is set to its zero position, the distance from the axis of joint 1 to the axis of joint 4 is defined by a parameter described below.

4. Joint 4 is a revolute axis that rotates the tool mounting flange about a world Z direction.  A positive change in its joint angle corresponds to a negative rotation about an axis that is parallel to the world Z axis.  When joints 1 and 4 are at their zero positions, the X axis of the tool flange is pointed in the +X world direction, the Y axis is pointed in the –Y world direction, and the Z axis is pointed in the –Z world direction.

Maximum operating range of rotational joints

This module has two rotary joints. Their maximum operating range is as follows:

Joint 1:            -179.9° to +179.9°
Joint 4:            -359.9° to +359.9°

Warning
Be sure to set the software joint limits properly before attempting to move the robot in a V+ program. It is especially important for revolute axes to have correct software limits set before attempting any motion instruction. If the limits are improperly set, a revolute axis can rotate unexpectedly in order to stay in range.

Variations in Axis Configuration

This module controls all four axes as defined above and cannot be reconfigured for any other number of axes.

Geometric Dimensional Constants

There are a number of dimensional constants that are utilized by this module.  The values are defined as follows:

Tool Z offset – this value can be used to change the apparent height of the robot’s tool flange.  The Tool Z offset should be set to the distance below joint 3 (the horizontal axis) that the tool flange is located.

Joint 2 offset – this is an offset value that is added to the extension of joint 2 to determine the height of joint 3 above the world X-Y plane.  When joint 2 is zero, the world Z position of joint 3 is equal to the joint 2 offset.  This value must be specified in millimeters.

Joint 3 offset – this  value is the  the distance between the axis of rotation of joint 1 and the axis of rotation of joint 4 when joint 3 is at its zero position.  This value must be specified in millimeters.

Reserved parameter – this value must always be zero.  It is included to permit the robot module to be enhanced in the future.

See the table below and Figure 1 for more information.

Link Dimension Parameters for Cylindrical Robot
	Parameter	Units	Value
LA	Tool Z-offset distance	mm
LB	Joint 2 offset	mm	j20
LC	Joint 3 offset	mm	j30
LD	Reserved parameter		must be 0

 

Figure 1.  Link Definitions and Dimensions for a Cylindrical Robot

Interpretations of Cartesian Rotation

During program-generated straight-line motions, the first Cartesian rotation speed controls the rate at which the tool mounting flange rotates about a vector pointed in the +Z world direction.

Coupling Between Robot Joints and Motors

This module does not allow multiple motors to couple into the motion of any single axis of rotation.

Robot Configuration Control Program Instructions

The following configuration program instructions affect the range of motion for joint 4:

SINGLE, MULTIPLE

If SINGLE is in effect, when a transformation is converted to joint angles, values for the angular position of joint 4 are restricted to the range -180 to +180 degrees.  When MULTIPLE is in effect, the full range of motion for joint 4 will be utilized.

(see the V+ Reference Guide for more information on these instructions.)

The following robot configuration-control program instructions do not have any effect upon the operation of mechanisms controlled by this module:

RIGHTY, LEFTY, ABOVE, BELOW, FLIP, NOFLIP

Additional Restrictions

None.