Vs = Vx 2 + Vy 2

The vector distance is the integral of Vs, or the total distance traveled along the path. To illustrate this further, suppose that a string was placed along the path in the X-Y plane. The length of that string represents the distance traveled by the vector motion.

The vector velocity is specified independently of the path to allow continuous motion. The path is specified as a collection of segments. For the purpose of specifying the path, define a special X-Y coordinate system whose origin is the starting point of the sequence. Each linear segment is specified by the X-Y coordinate of the final point expressed in units of resolution, and each circular arc is defined by the arc radius, the starting angle, and the angular width of the arc. The zero angle corresponds to the positive direction of the X-axis and the CCW direction of rotation is positive. Angles are expressed in degrees, and the resolution is 1/256th of a degree. For example, the path shown in Fig. 12.2 is specified by the instructions:

 

VP

0,10000

 

 

CR

10000, 180, -90

 

 

VP

20000, 20000

 

 

Y

 

 

20000

 

C

D

10000

B

 

 

 

A

 

X

 

 

10000

20000

Figure 12.2 - X-Y Motion Path

 

 

The first line describes the straight line vector segment between points A and B. The next segment is a circular arc, which starts at an angle of 180° and traverses -90°. Finally, the third line describes the linear segment between points C and D. Note that the total length of the motion consists of the segments:

A-B Linear

10000 units

USER MANUAL

Appendices • 199

Page 199
Image 199
Galil DMC-13X8 user manual Vs = Vx 2 + Vy