Experiment 3

EXPERIMENT 3 SORTATION OF PARTS ON THE BASIS OF THEIR WIDTH USING A ROBOT APPARATUS: •

Conveyer assembly

•

Cylinders of different width

•

Robot Assembly

THEORY: Robot has profound applications in material handling. The robot moves parts from one place to another. To accomplish the transfer, the robot is equipped with a gripper type end effector. The gripper must be designed to handle the specific part or parts that are to be moved in the application. In material transfer primary purpose of the robot is to pick up parts at one location and place them at a new location. In man y cases, reorientation of the part is accomplished during the relocation. The basic application in this category is the relatively simple pick and place operation, in which robot picks a part and places it at a new location. Only two, three or four joints are required for most of the time. Pneumatically powered robots are often employed. However, here we have a conveyor assembly which has the following main components: •

Part dispenser

•

Limit Switch: It senses whether a part has been dispensed or not. It starts a timer so that the part could stop at the width gauge

•

Width Gauge: It uses a progressing arm that touches the part and gives the corresponding dimension to the computer and the observer simply checks the width by looking in the software

Here, the robot is required to pick and place cylinders of varying width at different locations of interest. Limits for the width are set and a particular part below that limit is placed at, say, Location A and cylinder exceeding the limit is placed at another location say B. Robot used has the following configuration ROBOT CONFIGURATION: Jointed Arm (TRR)

CONTROL SYSTEM: Point to Point with playback ROBOT NAME: Gryphon PROCEDURE: •

A defined range of cylinders is given below and above of which the part would be rejected

•

We enter two programs in the instructions one labeled as ‘big’ and the other ‘small’. Small parts have the dimensions in the range of 21 to 23 mm and big parts have dimensions 27 to 29 mm

•

Robot is programmed through powered leadthrough to move through series of points which are different for ‘small’ program and ‘big ‘program. The robot places a big part at a specific location be it A and small part at another location say B

•

The rough sketch of the program is as follows: Disp Part 1 Start conv 1 Wait until digital sens 1 is on Move conv 125mm Gauge width 1 Move conv 1 200 mm If width gauge 1 is between 21 and 23 then Go to small If width gauge 1 is between 27 to 29 Go to big Go to start

•

After Go to Start the program runs either the small program or the big program depending upon the part detected

•

Small and Big programs basically consists of series of points to direct the robot to a specific location to place the part