General Robotics Flashcards
Can accuracy be measured?
Accuracy is ABSOLUTE and so has a measurement (in mm)
Can repeatability be measured?
Repeatability is RELATIVE and so can only be compared
What are 3 types of robot power sources (for motion)
> Hydraulic
Electromechanical
Pneumatic
What are 4 examples of sensors?
> Position sensor
Range sensor
Velocity sensor
Proximity sensor
What are the 3 classes of robotic motion?
> Pick and place
Continuous
What are different robotic control modes?
> Point-to-point
> Path / trajectory controlled motion
What is point to point control? (4)
> Only the end points are programmed, the path used to connect the end points are computed by the controller
The user can control the velocity and may permit linear or piece wise linear motion
Pick and place type operations
All axes start and end simultaneously
What is Path / trajectory controlled motion?
> In addition to the control over the endpoints, the path taken by the end effector is controlled
Path is controlled by manipulating the joints throughout the entire motion, via closed loop control
Spray painting applications
Here the motion is preformed through a time sequence of intermediate configurations computed ahead of time
This motion is a continuous scheme to move the tool centre point (TCP) from one location to the next along the desired (straight or curved)
What is open-loop control?
> There is no sensor feedback
The controller is told where the output device needs to be
Once the controller sends the signal to the motor it does not receive feedback to know if it has reached the desired position
Cheaper than closed loop
What is closed-loop control?
> This is when sensors are used to give feedback about the position and motion of the robot and its end effector. . > This is used to react to different situations
What is On-Off control?
> Simplest closed loop
When an error is identified the system goes into full corrective state.
Can tend to over shoot desired.
Will never reach the exact position
What is the working volume?
This is the space that the endeffector can operate
What is a trade off for a faster robot?
Resolution
What are the different robot size classes?
Micro : <1m
Small: 1-2m
Medium: 2-5m
Large: >5
What are some prismatic joints?
O - Joint
L - Joint
