Galil DMC-1700, DMC-1800 Command Summary - Contour Mode, ω= ΑΒ 1 − cos2π Β Χ= ATB − 2Aπ sin2π B

Command Summary - Contour Mode

COMMAND

CM XYZW

CM ABCDEFGH

CD x,y,z,w

CD a,b,c,d,e,f,g,h

DT n

WC

DESCRIPTION

Specifies which axes for contouring mode. Any non-contouring axes may be operated in other modes.

Contour axes for DMC-1780/1880

Specifies position increment over time interval. Range is +/-32,000. (Zero ends contour mode, when issued following DT0.)

Position increment data for DMC-1780/1880

Specifies time interval 2n msec for position increment, where n is an integer between 1 and

8.Zero ends contour mode. If n does not change, it does not need to be specified with each CD.

Waits for previous time interval to be complete before next data record is processed.

General Velocity Profiles

The Contour Mode is ideal for generating any arbitrary velocity profiles. The velocity profile can be specified as a mathematical function or as a collection of points.

The design includes two parts: Generating an array with data points and running the program.

Generating an Array - An Example

Consider the velocity and position profiles shown in Fig. 6.7. The objective is to rotate a motor a distance of 6000 counts in 120 ms. The velocity profile is sinusoidal to reduce the jerk and the system vibration. If we describe the position displacement in terms of A counts in B milliseconds, we can describe the motion in the following manner:

ω= ΑΒ (1 − cos(2π Β))

Χ= ATB − 2Aπ sin(2π B)

Note: ω is the angular velocity; X is the position; and T is the variable, time, in milliseconds. In the given example, A=6000 and B=120, the position and velocity profiles are:

X = 50T - (6000/2π) sin (2π T/120) Note that the velocity, ω, in count/ms, is

ω= 50 [1 - cos 2π T/120]

DMC-1700/1800 Chapter 6 Programming Motion • 115