Concatenation of Movements

Introduction

Using ControlStudio, two motions can be "glued" together using a non-zero final velocity value. This method is called concatenation. It is a basic way of blending. Each motion is fully executed according to its interpolation specification, as opposed to blending (CP, SP or AI) where the path is modified to fit to the motion constraints.

Issuing Concatenation

Depending if the given motion element is a group/axis or a robot, the following final-velocity properties are used:

• Group/axis: VFINAL (comes together with VCRUISE).
• Robot : VFTRAN and VFROT (comes together with VTRAN and VROT).

Special Issues

Profiling

• It is important to note that when specifying final velocity that the actual final velocity can differ. The system motion profiler tries to generate the best (fastest) motion profile under the given limitations. The actual obtained final velocity will depend on initial velocity of the movement, movement length and all the motion limitations (acceleration/deceleration max, jerk max, etc.).

• In case a series of concatenated motions is issued and the last one starts with such a high velocity that the movement can not be stopped at the end, an AUTOMATIC BRAKING error will be sent to the user.

• In case the final velocity is too high the biggest achievable final velocity will be reached instead.

Discretization

Discretization is a phenomenon occurring in motion-concatenation. A movement that ends with non-zero final velocity can never exactly end at the last motion sample. As a motion profile generation is done in every system sample at a specified sample rate the last sample will never be exact. In other words: $v\cdot n\cdot T\neq L$

The overshoot will be transferred to the next movement as its new initial position. In cases of transitions between circles and lines the appropriate projection-factor will be taken into account.

The example below shoes two movements (to A and then to B):

MOVE A vcruise = 100 vfinal = 100
MOVE B vcruise = 100

it is important to notice that the second motion will start from a point that is little bit further off from the point A.

Path-PLS

In case of motion concatenation and PLS, the second movement will miss the PLS set at 0% as 0% actually never happens.