4 UNIMATION PUMA (360, 550, 560 SERIES)

page 320



maximum static torque



1.5Nm



• joint 5 (Wrist Bend)

joint type

range

max slew rate

resolution

maximum static torque



revolute

235°

5.6 rad/sec.

.000199 rad/bit

1.4Nm



• joint 6 (Flange Rotation)

joint type

range

max slew rate

resolution

maximum static torque



revolute

525°

5.2 rad/sec.

.000247 rad/bit

1.1Nm



10.5 PRACTICE PROBLEMS



2. Write a short program to direct a robot to pick up and put down a block. Assume the points

have already been programmed with the teach pendants.

a) Write program for the IBM 7535.

b) Write program for the Seiko RT-3000.



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ans. a)



NEWPROG:BLOCK;

RELEASE; -- open the gripper

DELAY(5); -- delay 1/2 second to allow the gripper to open

PMOVE(OVER); -- move to the point over the pickup point called ‘OVER’

DOWN; -- move the arm down

DELAY(2); -- wait for the motion to complete and settle

GRASP; -- close the gripper

DELAY(2); -- wait for the gripper to close

UP; -- raise the block

DELAY(20); -- wait for a couple of seconds

DOWN; -- drop the block back to the surface of the table

OPEN; -- open the gripper

UP; move the arm away from the block

END; - terminate the program



10. You have been asked to write a program for a Seiko RT-3000. The program is to pick up

a part at point T1, move to point T2, and then load the part into a pallet. The robot should then

return to point A to pick up then next part. This should continue until the pallet is full.



T1 = (300, 300, 20)

T2 = (-300, 300, 0)

Pallet has 6 rows and 7 columns

Pallet origin T3 = (300, 0, 0)

Pallet end of row T4 = (350, 0, 0)

Pallet end of column T5 = (300, 60, 0)



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ans.



10 T1 = 300. 300. 20. 0.

20 T2 = -300. 300. 0. 0.

30 T3 = 300. 0. 0. 0.

40 T4 = 350. 0. 0. 0.

50 T5 = 300. 60. 0. 0.

60 R = 6

70 C = 7

80 OUTPUT +OG3

90 DEF PA2(R, C) T3 T4 T5

100 FOR I = 0 TO R-1

110 FOR J = 0 TO C-1

120 MOVE T1

130 OUTPUT -OG3 200

140 MOVE T2

150 MOVE PA2(J, I)

160 OUTPUT +OG3 200

170 NEXT J

180 NEXT I

190 STOP



11. An IBM 7535 industrial robot is to be used to unload small 1 lb. cardboard boxes (5” by

4” by 1”) from a conveyor, and stack them in a large cardboard box (20” by 8” and 2” deep). After

the large box is loaded, it will be removed automatically and replaced with an empty one. The

conveyor will be controlled by a robot output, and it will be stopped when an optical sensor

detects a small box. When the box is full the conveyor will be stopped and a light turned on until

an unload button is pushed. The entire system uses a start and stop button combination. The stop

button is not an e-stop, but it will stop the cycle after the small box is placed in the large box.

a) Layout the position of the conveyor, sensor, large box and robot so that all positions can

be reached. Indicate critical points of objects.

b) Design a robot gripper to pick up the boxes.

c) Develop a flow chart for the robot operations.

d) Write an AML program for the flowchart.



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ans. a)

First, we need to convert the given dimensions to mm.

small boxes = 127x101.6x25.4mm

large boxes = 508x203.2x76.2mm

Next, we need to overlay these on the robot workspace. In this case there is abundant space and can be done by inspection.

( 0, 650, 0 )

A

127/2mm



y



photo

sensor



x

z



D

( – 650, 0, 0 )

( 650, 0, 0 )

B C



A = (0, 650-101.6/2, 0) = (0, 599.2, 0)

B = (-400, -1.5*127, 0) = (-400, -190.5, 0)

C = (-400 + 101.6, -1.5*127, 0) = (-298.4, -190.5, 0)

D = (-400, 1.5*127, 0) = (-400, 190.5, 0)



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ans. b)

For this application, vacuum grippers should work effectively because the mass is light,

and the boxes should have clean cardboard faces. Because the application has been

designed to lift the boxes in the centers, we should be able to use a single suction cup,

but a large factor of safety will be used to compensate (>= 3). We will assume that we

are using a venturi valve to generate the suction, so a pressure differential of 3psi is reasonable.

( W )FS = PA min

lb1lb3 = 3 ------ Amin

2

in

A min = 1in



2



d min 2

A min ≤ π  --------- 

 2 -

d min 2

2

1in ≤ π  --------- 

 2 -

d min = 1.13in

Based on this calculation I would select a suction cup that is 1.25” or 1.5” dia.



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ans. c)



Start



reset pallet values



no



start

button pushed?

yes

pick up small box



index pallet



move above box

no

is box full?



no



stop pushed?



yes

turn off conveyor

turn on light



reset button?



no



yes



12. Repeat the previous problem for the Seiko RT-3000 robot.



yes



page 326



ans. a)

First, we need to convert the given dimensions to mm.

small boxes = 127x101.6x25.4mm

large boxes = 508x203.2x76.2mm

Next, we need to overlay these on the robot workspace. In this case there is abundant space and can be done by inspection.

( 0, 500, 0 )

y



A

photo

sensor

D



x



127/2mm



( – 500, 0, 0 )



B C



A = (0, 500-101.6/2, 0) = (0, 449.2, 0)

B = (-350, -1.5*127, 0) = (-350, -190.5, 0)

C = (-350 + 101.6, -1.5*127, 0) = (-248.4, -190.5, 0)

D = (-350, 1.5*127, 0) = (-350, 190.5, 0)



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ans. b)

For this application, vacuum grippers should work effectively because the mass is light,

and the boxes should have clean cardboard faces. Because the application has been

designed to lift the boxes in the centers, we should be able to use a single suction cup,

but a large factor of safety will be used to compensate (>= 3). We will assume that we

are using a venturi valve to generate the suction, so a pressure differential of 3psi is reasonable.

( W )FS = PA min

lb1lb3 = 3 ------ Amin

2

in

A min = 1in



2



d min 2

A min ≤ π  --------- 

 2 -

d min 2

2

1in ≤ π  --------- 

 2 -

d min = 1.13in

Based on this calculation I would select a suction cup that is 1.25” or 1.5” dia.



page 328



ans. c)



Start



reset pallet values



no



start

button pushed?

yes

pick up small box



index pallet



move above box

no

is box full?



no



yes

turn off conveyor

turn on light



reset button?

yes



no



stop pushed?



yes



page 329



ans.



10 R = 3: C = 4: H = 0 ‘ define rows and column variables

20 SPEED 100 ‘ set the robot speed

30 T1 = 0. 449.2 0. 0. ‘ set point A

40 T2 = -350. 449.2 -190.5 0. ‘ set point B

50 T3 = -248.4 449.2 -190.5 0. ‘ set point C

60 T4 = -350. 449.2 190.5 0. ‘ set point D

70 T5 = 0. 0. -50. 0. ‘ a displacement to the conveyor height

80 T6 = 0. 0. -100.4 0. ‘ a displacement to the bottom layer of the large box

90 T7 = 0. 0. -75. 0. ‘ a displacement to the top layer of the large box

100 DEF PA2(4,2) T1 T2 T3 ‘ define pallet

110 WAIT +IE1 ‘ wait for external input #1 to go on, this is the start button

120 FOR H = 0 TO 1 ‘ set box layers

130 FOR I = 0 TO R-1 ‘ loop for rows

140 FOR J = 0 TO C-1 ‘ loop for columns

150 OUTPUT +OE1 ‘ turn on external output #1, this is the conveyor

160 MOVE T1 ‘ move to the conveyor pickup point

170 WAIT +IE2 ‘ wait for the input from the optical sensor to go on

180 OUTPUT -OE1 ‘ turn off the conveyor

190 MOVE T1 + T5 ‘ move to pick up box

200 OUTPUT +OG1 ‘ turn on suction cup on gripper

210 MOVE T1 ‘ pick up the box

220 MOVE PA2(I, J) ‘ move to the pallet position in the large box

230 IF H = 1 THEN GOTO 260 ‘ jump if on the top layer

240 MOVE PA2(I, J) + T6 ‘ move to the bottom layer of the box

250 GOTO 270

260 MOVE PA2(I, J) + T7 ‘ move to the bottom layer of the box

270 OUTPUT -OG1 ‘ turn off the suction cup

280 MOVE PA2(I, J) ‘ move out of box

290 IF NOT IE3 THEN GOTO 310

300 WAIT +IE1 ‘ wait for the start button

310 NEXT J: NEXT I: NEXT H ‘ end of the loops

320 OUTPUT +OE2 ‘ turn on box full light

330 WAIT +IE4 ‘ wait for the reset button

340 GOTO 110 ‘ go back to start anew



14. The IBM 7535 robot arm moves its TCP to point (-450, 250)mm at speeds programmed

by ‘payload(5)’ and decelerates from the resultant speed to zero in 0.5 seconds. The tool has a



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mass of 1.5 kg with its center of gravity at 3cm from the TCP and transfers a mass of 4kg with its

C.G. at 5cm from the TCP.

a) determine the inertia torque about the theta1 axis showing all correct units

b) compare the value in a) with a maximum inertia torque estimated from decelerating a

6kg mass from 1100mm/s to zero in 0.5 sec.

c) Estimate the combined error at the CG of the load due to theta1 and theta 2 resolution



10.6 LABORATORY - SEIKO RT-3000 ROBOT

Purpose:

Introduction to the Seiko RT-3000 robot and programming methods.

Overview:

This laboratory will involve a basic tutorial on the use of the robot, including safety. The

students will have prepared a program for the robot ahead of class. During the laboratory the robot will be programmed and tested using the prepared programs. A

simple accuracy and repeatability test will be conducted.

Pre-Lab:

1. Use Netscape Communicator to access the robots in the laboratory, explore the site.

2. Review the note section on the Seiko RT-3000. After this use the on-line robot to write

a simple test program.

3. Write a program to pick up pop cans at one point, and put them down at another point.

This program should repeat five times in a row. Test the program on the robot.

In-Lab:

1. Examine the robot and all associated cables, including the pneumatics. Make sure the

settings match the manual specifications.

2. Examine the buttons on the front and connectors on the back of the controller box.

Match these up to the input/output points. Determine if these are TTL, sourcing, or

some other type.

3. Turn on the robot and use the teach pendant, with the commands below, to control the

robot.

4. Turn the robot controller off, connect it to a computer, and then turn it back on. Turn the

servo power on and then type in the command home. The robot will move and find

its reference position. You may then type in commands at the prompt.