VEGA DEVICE MODULES
The Vega device module disk contains two files. The first file consists of the following two modules:
1. SCARA Robot Module with Linear Joint 2 (SCARAFLEX)
2. Secondary SCARA Robot Module with Linear Joint 2
The second file contains:
3. 4R Robot With Fixed Tool Z Orientation and Two Linear Drives (POLYFLEX)
Copying the Device Module File to a Boot Disk
In order to control any of these mechanisms, the device module file must be transferred to a system boot disk. Refer to the "Software Configuration" chapter in the AdeptMotion User’s Guide for details on using DM_UTIL to install this device module file on your system boot disk.
DM_UTIL will prompt you to put the device modules disk into your floppy drive. When you put the disk containing this device module file in the drive, if you want the SCARA Robot Module, answer "VGA" to the prompt asking you to enter the name of the device module you want to transfer to your system disk. If you want to load the 4R Robot module, answer “V4R” to the prompt. You can enter a “?” to the name prompt and the available device module names will be displayed.
1. SCARA Robot Module with Linear Joint 2
This robot module controls a SCARA mechanism with four or five degrees of freedom.
Module Specifications
Device module identification number: 6
This number is displayed along with the robot serial and model number after the system boots up and whenever the ID monitor command is issued.
Default startup message: "General SCARA Robot Control Module"
The startup message is displayed just after the system boots up.
Default joint configuration:
Joint
Axis
Board/Channel
1
1 ("shoulder")
4/1
2
2 ("elbow" or Z)
4/2
3
3 (Z or "elbow")
4/3
4
4 (Roll)
4/4
5
5 (Pitch)
5/1
With multiple robots, it will be necessary to correct the joint configuration from the SPEC program to avoid conflicts.
Robot Option Word
The robot option word determines whether the robot's linear axis is joint 2 or joint 3. If bit 3 (option word value 8) is set, then the linear axis is joint 2; if not, it is joint 3. See the AdeptMotion Servo User's Guide for details on setting the robot option word.
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, the inner link (the link between joint 1 and joint 2) will point along the world X axis. When joint 1 is positioned at 90 degrees, the inner link will point along the world Y axis.
2. Joint 2 (joint 3 if the robot option word bit 3 is set) is a revolute axis whose axis of rotation is parallel to the first joint. A positive change in joint angle corresponds to a positive rotation about an axis parallel to the world Z axis. When joints 1 and 2 are positioned at zero, both the inner and the outer links will point along the world X axis. If joint 2 is subsequently rotated to 90 degrees, the outer link will point in the positive world Y direction.
3. Joint 3 (joint 2 if robot option word bit 3 is set) is a linear axis that moves in the world Z direction. A positive displacement of the joint moves the robot's tool in a negative (positive if robot option word bit 3 is set) world Z direction. For a four-axis SCARA, when this joint is set to its zero position, the height of the tool mounting flange above the world X-Y plane is defined by a parameter described below. For a five-axis SCARA, when this joint is set to its zero position, the height of the center of rotation of the fifth axis above the world X-Y plane must be specified.
4. Joint 4 is a revolute axis that rotates the tool mounting flange (or the fifth axis) 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. For a four-axis SCARA, when joints 1, 2, 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.
5. The optional joint 5 is a revolute axis whose axis of rotation is parallel to the X-Y world plane. When joints 1, 2, 4, and 5 are at their zero positions, the X axis of the tool mounting 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. If joint 5 is subsequently rotated in a positive direction, the tool mounting flange will be rotated about an axis parallel to the negative world Y axis.
Variations in Axis Configuration
This module can be configured to control the first four axes of the SCARA robot or all five axes.
Geometric Dimensional Constants
There are a number of dimensional constants that are utilized by this module. Most of the constants are a function of three primary parameters: the length of the first link (the distance from the first to the second joint axes), the length of the second link (the distance from the second to the fourth joint axes), and the height of the tool flange above the X-Y world plane when the linear joint is at its zero position. As a convenience, the SPEC program prompts for the primary three parameters and automatically computes all of the other required dimensional constants. See the table below and Figure 1 and Figure 2 for more information.
Link Dimension Parameters for SCARA Robot
Parameter
Units
Value
LA
Tool Z-offset distance
mm
LB
Length of first link
mm
a1
LC
Length of second link
mm
a2
LD
Height of tool flange
mm
s1 + s2 – s3
Figure 1. Link Definitions and Dimensions for a SCARA Robot with a Linear Joint 2
Figure 2. Link Definitions and Dimensions for a SCARA Robot with a Linear Joint 3
Interpretations of Cartesian Rotation
During program-generated straight-line motions, the first Cartesian rotation speed controls the rate at which the tool mounting flange (or joint 5) rotates about a vector pointed in the +Z world direction. For a five-axis SCARA, the second Cartesian rotation speed controls the rate at which joint 5 rotates during straight-line motions.
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 robot configuration-control program instructions are utilized to specify the range of motion for the outer link:
LEFTY, RIGHTY
(see the V+ Language User’s Guide and the V+ Language 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:
ABOVE, BELOW, FLIP, NOFLIP
Additional Restrictions
None.
2. Secondary SCARA Robot Module with Linear Joint 2
This device module controls a SCARA robot mechanism with the following characteristics:
• The robot has four or five degrees of freedom.
• Joint 2 is the linear axis.
• The robot is attached to another "primary" SCARA robot such that joint 1 of this "secondary" robot is shared with the primary robot.
NOTE: This robot must be configured as robot number 2, with the primary SCARA robot configured as robot number 1. Also, ALL specifications for joint 1 of robot 2 must be identical to the specifications for joint 1 of robot 1, including the mapping of joint to servo board and channel.
The world coordinate frame of the primary robot is also the world coordinate frame of the secondary robot. The secondary robot has a default base rotation of 180 degrees about the world Z axis to compensate for the fact that the secondary robot points in the opposite direction from the primary robot. Since both robots share the same world coordinate frame, locations taught using the primary robot may be used to position the secondary robot, and vice versa.
When the location of the secondary robot is read, the value returned represents the position of joint 1 of the primary robot (plus the base rotation of 180 degrees) and the positions of joints 2 through 4 of the secondary robot. When the secondary robot is commanded to move under manual or program control, joints 2 through 4 respond in the normal fashion and the command for joint 1 is ignored. It is the responsibility of the programmer to ensure that joint 1 of the primary robot is always properly positioned to enable the secondary robot to achieve its target location.
Module Specifications
Device module identification number: 11
This number is displayed along with the robot serial and model number after the system boots up and whenever the ID monitor command is issued.
Default startup message: "Secondary SCARA Robot Control Module"
The startup message is displayed just after the system boots up.
Default joint configuration:
Joint
Axis
Board/Channel
1
1 (unused)
4/1*
2
2 (Z)
4/2
3
3 (elbow)
4/3
4
4 (Roll)
4/4
5
5 (Pitch)
5/1
*Must be identical to Robot 1.
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 (see the AdeptMotion Servo User's Guide for details on this value). You should leave its value at 0.
Axis Configuration
1. Joint 1 is a revolute axis that rotates about the world Z axis. It is the same physical joint as joint 1 of the primary robot and is controlled by the primary robot. A positive change in joint angle corresponds to a positive rotation about the world Z axis. When joint 1 is positioned at zero degrees, the inner link (the link between joint 1 and joint 3) of the secondary robot points along the negative world X axis. When joint 1 is positioned at 90 degrees, the inner link of the secondary robot points along the negative 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 tool in the positive world Z direction. For a four-axis SCARA, when joint 2 is set to its zero position, the height of the tool mounting flange above the world X-Y plane is defined by a parameter described below. For a five-axis SCARA, when joint 2 is set to its zero position, the height of the center of rotation of the fifth axis above the world X-Y plane must be specified.
3. Joint 3 is a revolute axis with its axis of rotation parallel to the first axis. A positive change in joint angle corresponds to a positive rotation about an axis parallel to the world Z axis. When joints 1 and 3 are positioned at zero, both the inner and the outer links point along the negative world X axis. If joint 3 is subsequently rotated to 90 degrees, the outer link will point in the negative world Y direction.
4. Joint 4 is a revolute axis that rotates the tool mounting flange (or the fifth axis) 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. For a four-axis SCARA, when joints 1, 3, and 4 are at their zero positions, the X axis of the tool flange is pointed in the negative world X direction, the tool Y axis is pointed in the positive world Y direction, and the tool Z axis is pointed in the negative world Z direction.
5. The optional joint 5 is a revolute axis with its axis of rotation parallel to the world X-Y plane. When joints 1, 3, 4, and 5 are at their zero positions, the X axis of the tool flange is pointed in the negative world X direction, the tool Y axis is pointed in the positive world Y direction, and the tool Z axis is pointed in the negative world Z direction. If joint 5 is subsequently rotated in a positive direction, the tool mounting flange will be rotated about an axis parallel to the negative world Y axis.
Variations in Axis Configuration
This module can be configured to control the first four axes of the SCARA robot, or all five axes.
Geometric Dimensional Constants
There are a number of dimensional constants that are utilized by this module. All of the constants are a function of three primary parameters: the length of the first link (the distance from the first to the third joint axes), the length of the second link (the distance from the third to the fourth joint axes), and the height of the tool flange above the X-Y world plane when joint 2 is at its zero position. As a convenience, the SPEC program prompts for the primary three parameters and automatically computes all of the other required dimensional constants. (See Geometric Dimensional Constants for SCARA robot in section 1.)
Interpretations of Cartesian Rotation
During program-generated straight-line motions, the first Cartesian rotation speed controls the rate at which the tool mounting flange (or joint 5) rotates about a vector pointed in the positive world Z direction. For a five-axis SCARA, the second Cartesian rotation speed controls the rate at which joint 5 rotates during straight-line motions.
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 robot configuration-control program instructions are utilized to specify the range of motion for joint 3:
LEFTY, RIGHTY
(see the V and 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:
ABOVE, BELOW, FLIP, NOFLIP
Additional Restrictions
This module must be configured as robot number 2, with robot number 1 being the (primary) SCARA robot module with linear joint 2. All specifications for joint 1 of robot 2 MUST be identical the the specifications for joint 1 of robot 1.
3. 4R Robot With Fixed Tool Z Orientation and Two Linear Drives
This robot module controls a mechanism with four degrees of freedom. All four joints are revolute, however, the second and third revolute joints are driven by linear ball screws. This mechanism includes a mechanical linkage that keeps the tool mounting flange pointed down in the direction of the –Z world axis.
Module specifications
Device module identification number: 12
This number is displayed along 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 Rotary Palletizer with 2 Linear Drives"
The startup message is displayed just after the system boots up.
Default joint configuration:
Joint
Axis
Board/Channel
1
1 (“torso”)
4/1
2
2 (“shoulder”)
4/2
3
3 (“elbow”)
4/3
4
4 (“roll wrist”)
4/4
Robot Option Word
This module does not use any bits of the robot option word (see the AdeptMotion Servo User's Guide for details on this value). You should leave its value at 0.
Axis Configuration
Specifically, the axes of the motion are defined as follows:
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, the inner link (the link positioned by the second motor) will generally point along the world X axis. When joint 1 is positioned at 90 degrees, the inner link will point along the world Y axis.
2. Joint 2 is a revolute axis that is powered by a linear ball screw. When joint 1 is at zero and the ball screw for joint 2 is extended, the inner link rotates in a negative direction about an axis parallel to the world Y axis. From a kinematic point of view, when the inner link is horizontal and points along the +X world axis, the angle for joint 2 can be considered to be zero. When the ball screw is extended and the inner link points up in the direction of the +Z world axis, the angle of rotation of joint 2 can be thought of as being at –90 degrees.
3. Joint 3 is a revolute axis whose axis of rotation is parallel to joint 2. Like joint 2, joint 3 is powered by a linear ball screw. However, unlike joint 2, when joint 3's ball screw is extended, the outer link rotates in the opposite direction from joint 2. That is, if joint 1 is at zero and the inner and outer links are horizontal, extending the ball screw for joint 2 will move the end of the inner link up while extending the ball screw for joint 3 will move the end of the outer link down. If the joint angles for joints 1, 2, and 3 are all at zero, both the inner and the outer links will point along the +X world axis. If the ball screw for joint 3 is then extended so that the outer link points down in the direction of the –Z world axis, joint 3 can be thought of as being at +90 degrees.
4. Joint 4 is a revolute axis (theta) about the world Z direction. Due to a mechanical linkage, the direction of the axis of rotation of joint 4 is always pointed down, independent of the motions of the first three joints. A positive rotation of the joint turns the robot's end effector in a negative direction relative to the world Z axis. The axis of rotation of joint 4 defines the nominal Z axis of the robot's tool frame of reference. That is, if a NULL tool is defined, the Z axis of the tool frame will be colinear with the axis of rotation of joint 4 and will be pointed in the direction of the negative world Z axis.
As with all robot modules, the standard V+ BASE and TOOL transformations can be used in combination with the geometric model to specify and compute the end point of the robot relative to the world coordinate frame.
Variations in Axis Configuration
This module can be configured to disable the use of either (or both) joint 1 and joint 4.
Geometric Dimensional Constants
There are a total of 14 dimensional constants that must be defined to specify the geometric transformations performed by this module. The first 8 constants define the geometry of the four axis revolute mechanism. The last 6 constants define the relationship between the two ball screws and the corresponding motions of their revolute axes. The equations for these 14 constants are defined in the following table and see Figure 3 for locations.
Link Dimension Parameters for Vega 4R Robot
Parameter
Units
Value
LA
Tool Z-offset distance
mm
LB
Link dimension value #1
mm
a2
LC
Link dimension value #2
mm
a3
LD
Link dimension value #3
mm
s1
LE
Link dimension value #4
–
a22 + a32
LF
Link dimension value #5
–
2a22a3
LG
Link dimension value #6
–
(2a2a3)2
LH
Link dimension value #7
–
2a2a3 sin(10°)
LI
Link dimension value #8
mm
a1 + a4
LJ
Link dimension value #9
–
b22 + c22 + f22
LK
Link dimension value #10
–
LL
Link dimension value #11
degrees
w2 – [tan-1 (c2 /b2) + g2]
LM
Link dimension value #12
–
b32 + c32 + f32
LN
Link dimension value #13
–
LO
Link dimension value #14
degrees
w3 + [tan-1 (c3 /b3) + g3]
g2 = 60° w2 = 90° g3= 180° w3= -180°
Figure 3. Link Definitions and Dimensions for the Vega 4R Robot
Interpretation of Cartesian Rotations
During program-generated straight-line motions, the first Cartesian rotation speed controls the rate at which joint 4 rotates, and the speed should be set to be consistent with the joint-interpolated speed for joint 4. If the theta axis is not configured, the first Cartesian rotation speed should be set to zero. The second and third Cartesian rotation angles are not utilized and their speeds should likewise be set to zero.
Coupling Between Robot Joints and Motors
This module does not allow the motors for the four axes to couple.
Robot Configuration Control Program Instructions
The following robot configuration control program instructions are utilized to specify the range of motion for joint 3:
ABOVE, BELOW
(see the V+ Language User’s Guide and the V+ Language 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:
LEFTY, RIGHTY, FLIP, NOFLIP
Additional Restrictions
None.
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Last modified on:
04/10/2007 |
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