Task 8. Choose the best alternative to fill in the blank in each of the following sentences.
Date: 2015-10-07; view: 475.
Task 7. Insert the appropriate word or word sensor combination from the box.
| a stepper motion motor pulse constant torque generator |
A typical open-loop … control system includes … with a programmable indexer or … and motor driver. This system does not need feedback sensors because load position and velocity are controlled by the predetermined number and direction of input digital pulses sent to the motor driver from the controller. Because load position is not continuously sampled by a feedback … (as in a closed-loop servosystem), load positioning accuracy is lower and position errors (commonly called step errors) accumulate over time. For these reasons open-loop systems are most often specified in applications where the load remains …, load motion is simple, and low positioning speed is acceptable.
There are five different kinds of motion control: point-to-point, sequencing, speed, …, and incremental. In point-to-point motion control the load is moved between sequences of numerically defined positions where it is stopped before it is moved to the next position. This is done at a constant speed, with both velocity and distance monitored by the motion controller.
1. When a load under control must follow a specific … to get from its starting point, the movements of the axes must be coordinated.
| a) path | b) way | c) theory |
2. There are three kinds of interpolation: linear, … , and contouring.
| a) straight | b) circular | c) triangular |
3. Linear interpolation is the ability of a … control system having two or more axes to move the load from one point to another in a straight line.
| a) method | b) movement | c) motion |
4. The motion controller must determine the speed of each axis so that it can … their movements.
| a) equal | b) coordinate | c) harmonize |
5. True linear interpolation requires that the motion controller modify axis … .
| a) speeding-up | b) acceleration | c) accelerate |
6. The path can lie in one plane or be three … .
| a) lengthen | b) sized | c) dimensional |
7. Circular interpolation is the ability of a motion control system having two or more axes to move the load around a circular … .
| a) trajectory | b) axis | c) way |
8. It requires that the motion controller … load acceleration while it is in transit.
| a) change | b) modify | c) alter |
9. … is the path followed by the load, tool, or end-effector under the coordinated control of two or more axes.
| a) Contouring | b) Forming | c) Welding |
10. It requires that the motion controller change the speeds on different axes so that their trajectories pass through a set of … points.
| a) established in advance | b) limited | c) predefined |
11. Load speed is determined along the trajectory, and it can be … except during starting and stopping.
| a) persistent | b) permanent-type | c) constant |
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| Task 5. Read the text and write a short plan of it. | | |