Zusammenfassung der Ressource
Programming Methods
- Teach Programming
- Point to Point
- most common method
- robot moved to each point in turn and the point recorded
- recored position of joints in controllers memory
- teach pendant used
- hand held device connected to robot controller
- easier to manoeuvre using cartesian co-ordinates (not joint coordinates)
- joint coordinates need to be transformed to cartesian co-ordinates
- Kinematic model of robot used
- cylindrical coordinate can be used
- useful when FMC is arranges in circle
- Disadvantages
- any path can be taken by robot to reach the coordinates
- dangerous
- could bang into objects
- velocity each joint moves proportional to distance
- so all joints take same time to move to their new positions
- joint interpolated control
- allows robot to move with maximum velocity
- desirable joints move in straight line to avoid collision
- computer creates series closely spaced target points
- joins successive taught points
- closer the points the straighter the line
- useful if robot needs to follow outline of complex shape
- robot controller sends signals to other equipment
- robot receives signals from sensors
- simple programming language
- Continuous
- programmer holds end of robot arm and moves it along path
- spray painting
- joint positions recorded automatically at series of closely spaced points
- teaching arm available which is lighter and more representative of movement of spray gun
- can not be used for precision
- NOT for arc welding (point to point)
- disadvantages
- risk to programmer in such close proximity to the robot
- positioning relies on human judgement (error prone)
- teaching and debugging very time consuming
- robot out of work whilst being programmed
- mas production not too bad because used for long time
- Batch new programme has to be taught regularly
- accepted form of programming
- high degree of accuracy
- arm moves where its been taught
- Off Line Programming
- programme CNC machine tools
- doesn't involve any other equipment so no collisions
- part remains in one position so no transformations required
- generate robot programme away from robot
- programme created on computer using know data about geometry
- precise data used
- robot does not need to be taken out of production
- Disadvantages
- accurate data is required
- programmer may have problems visualising movement of robot
- need to prevent it from colliding with things
- kinematic models required to transform cartesian co-ordinates to joint coordinates
- kinematic models not perfect representations
- simplified models reduce time but reduce degree of accuracy
- costly for all the programming
- Computer simulations with 3D models of robot cells can be used
- expected to replace teach programming