Transformation types

ID 1: e function


Example:

trafo.command_pos.param[0]  10000   (h)

trafo.command_pos.param[1]  1.0     (k0)

trafo.command_pos.param[2]  2.0     (k1)

trafo.command_pos.param[3]  1.0     (k2)

trafo.command_pos.param[4]  1800000 (normalisation of motor angle)

Graphic diagram of e-function
Graphic diagram of e-function

ID2: Crank

Kinematic structure of slider crank
Kinematic structure of slider crank

Example:

trafo.command_pos.param[0]  1000000 (crank length l1)

trafo.command_pos.param[1]  3000000 (con-rod- length l2)

trafo.command_pos.param[2]  0       (eccentricity e)

trafo.command_pos.param[3]  0       (solution range for motor angle)

trafo.command_pos.param[3]  0       (movement direction of linear axis)

Graphic diagram of transfer function
Graphic diagram of transfer function

Notice

notice

In the event of eccentricity e != 0 and specific parameter settings (e.g. (l2-l1) < e), there may be limits to the motor angle movement range because of jamming in the kinematic structure. In this case, the motor angle movement range of both solutions is smaller than 360 degrees (see figure below).

Extreme positions of slider crank with eccentricity
Extreme positions of slider crank with eccentricity

ID3: Eccenter

Kinematic diagram of the eccenter function
Kinematic diagram of the eccenter function
Graphic diagram of the eccenter function
Graphic diagram of the eccenter function

Example:

trafo.command_pos.param[0]  1000000 (eccenter radius R)

trafo.command_pos.param[1]  0       (offset zero position linear axis)

trafo.command_pos.param[2]  0       (offset zero position rotary axis)

trafo.command_pos.param[3]  0       (solution range angle)

ID4: Crank with linkage by linear axis

Kinematic structure of crank and linkage
Kinematic structure of crank and linkage

Example:

trafo.command_pos.param[0]  1000000 (distance la joint point)

trafo.command_pos.param[1]  1410000 (distance lb joint point)

trafo.command_pos.param[2]  1000000 (crank length lh)

trafo.command_pos.param[3]  0       (offset zero position)

trafo.command_pos.param[4]  0       (movement direction of rotary axis)

Graphic diagram of transfer function
Graphic diagram of transfer function

If the kinematic (β=0) is in zero position, the transformation delivers the drive position 0 for ls. If necessary, by param[3] an offset to this position can be defined. (Example: Drive position at β=0 is 50mm -> the offset value has to be set on 50mm). Mathematically, the default rotational direction of the B axis is positive. This can be adapted by the parameter trafo.command_pos.param[4], see figure below.

Zero offset point of drive position
Zero offset point of drive position

ID5: Angular kinematic

Available as of CNC Build V3.1.3107.41/V4.3.0.

A linear movement results from the angular movement.

The parameters specify the lengths l1,l2 and lh. The maximum excursions are defined by the parameters γmax and γmin.

Angular kinematic
Angular kinematic

Example:

trafo.command_pos.param[0]  1900000 (length of distance l1)

trafo.command_pos.param[1]  600000  (length of distance l2)

trafo.command_pos.param[2]  4428300 (length of distance lh)

trafo.command_pos.param[3] -450000  (angle excursion lower limit γmin)

trafo.command_pos.param[4]  450000  (angle excursion upper limit γmax)

trafo.command_pos.param[5]  0/3400000 (position offset)

trafo.command_pos.param[6]  0       (angle offset)

trafo.command_pos.param[7]  0       (angle inversion)

trafo.command_pos.param[8]  0       (linear position inversion)

Below is the transfer function with and without position offset

Red: without position offset

Light blue: with posi8tion offset

Transfer function with and without position offset
Transfer function with and without position offset

Angle offset and angle inversion

In addition to the example above, the angle can be provided with an angle offset by parameters and can also be inverted.

trafo.command_pos.param[0]  1900000 (length of distance l1)

trafo.command_pos.param[1]  600000  (length of distance l2)

trafo.command_pos.param[2]  4428300 (length of distance lh)

trafo.command_pos.param[3] -450000  (angle excursion lower limit γmin)

trafo.command_pos.param[4]  450000  (angle excursion upper limit γmax)

trafo.command_pos.param[5]  3400000 (position offset)

trafo.command_pos.param[6]  250000   (angle offset)

trafo.command_pos.param[7]  0/1       (angle inversion)

trafo.command_pos.param[8]  0       (linear position inversion)

The following transfer function is with and without angle inversion.

Red: without angle inversion

Light blue: with angle inversion

Transfer function with and without angle inversion
Transfer function with and without angle inversion

Linear position inversion

Based on the example above, the linear position can be inverted.

trafo.command_pos.param[0]  1900000 (length of distance l1)

trafo.command_pos.param[1]  600000  (length of distance l2)

trafo.command_pos.param[2]  4428300 (length of distance lh)

trafo.command_pos.param[3] -450000  (angle excursion lower limit γmin)

trafo.command_pos.param[4]  450000  (angle excursion upper limit γmax)

trafo.command_pos.param[5]  3400000 (position offset)

trafo.command_pos.param[6]  250000   (angle offset)

trafo.command_pos.param[7]  0       (angle inversion)

trafo.command_pos.param[8]  0/1       (linear position inversion)

The following transfer function is with and without linear position inversion.

Red: without linear position inversion

Light blue: with linear position inversion

Transfer function with and without linear position inversion
Transfer function with and without linear position inversion

As a general rule, the following applies:

The specified angle of the kinematic has mathematical limits due to the specified input variables. If they are not observed, error ID 70342 is output.

ID 6: Symmetrical slider crank

In addition to identical lengths of crank and con-rod, this structure has an additional mechanical coupling between these elements so that no mechanical jamming can occur in the centre position of the slider (linear position).

Symmetrical slider crank solution range 0 to 180 degrees:

Symmetrical slider crank solution range 180 to 360 degrees:

Example:

trafo.command_pos.param[0]  1500000 (con-rod length == crank length)

trafo.command_pos.param[1]  0       (linear position offset)

trafo.command_pos.param[2]  0       (angle position offset)

trafo.command_pos.param[3]  0       (angle solution range)

Transfer function φ= f(x)

Transfer function of the symmetrical slider crank
Transfer function of the symmetrical slider crank