1.3 ACTUATORS

• There are a large number of power sources that may be used for robots.

• Typical actuators include,

• Pneumatics

- simple, low maintenance

- light, least expensive

- low payload

- easy to find fault

- hard to do continuous control

• Hydraulic

- large payload

- high power/weight ratio

- leakage

- noisy

• Electrical

- feedback compatible

- computer compatible

- EOAT compatible

- quiet, clean

- low power/weight ratio

• Actuators lead to various payload capabilities as shown in the following list.

1.3.1 Modeling the Robot

 

• If modeling only one link in motion, the model of the robot can treat all the links as a single moving rigid body,

 

 

• If multiple joints move at the same time, the model becomes non-linear, in this case there are two approaches taken,

1. Develop a full non-linear controller (can be very complicated).

2. Develop linear approximations of the model/control system in the middle of the normal workspace.