PTP control
In robotics and machine tools , the PTP control (PTP: Point to Point) or point control is the simplest - and a comparatively inexpensive and fast - type of control. It is a variant of CNC controls in which only initial and end point of a movement can be set. Target points can thus be approached precisely, but the path between the points is not defined in the program . The speed is not regulated during the axis movements. There is no interpolation between the axes.
The PTP control is used for loading , spot welding , punching , drilling and palletizing. A use for machining centers or milling machines is out of the question, as milling is not possible due to the lack of interpolation options. In some cases, machining centers with their own drilling block are colloquially referred to as point-to-point machines. However, this leads to the false assumption that these machines do not have to have any interpolating axes for milling.
This control can be divided into the following four types:
Asynchronous PTP control
All robot axes start moving simultaneously at their speed specified in the program. The axes reach the position required for the required target point at different times, so that the axis with the longest running time determines the duration of the movement.
Synchronous PTP control
A travel time is specified for all axes together. The control adjusts the speeds of the axes to the axis with the longest running time (master axis). All axes start at the same time and all reach their destination point at the same time.
PTP control with blending
In order to achieve the best possible time, the programmed point is not approached exactly, but rather is turned to the next point when its blending area is reached. With asynchronous control, blending begins when the last axis reaches the sphere, with synchronous control as soon as the leading axis penetrates the sphere.
Multipoint control
With the MP (multi-point control or also multi-point control), a dense sequence of time equidistant points is programmed in the playback process. The control appears to the outside as a path control . Path interpolator and coordinate transformation can be omitted. The speeds can typically be changed later or synchronized with external devices.
Individual evidence
- ↑ a b c WOOD TEC PEDIA: Point-to-Point. In: https://wtp.hoechsmann.com/home . Retrieved February 27, 2018 .