The current software version of the MovingCap Rabbit high-speed controller supports positioning mode and the associated CiA 402 operating states. The differences to the MovingCap standard controller are as follows:
•Positioning Mode only.(Velocity Mode is currently not available.)
•Only setting the zero position via REF35 is supported as a referencing method.
•New parameter 60A4h.0h profile jerk for the permissible acceleration change / jerk.
NOTE: There is no specific command for the jerk setting in the Python mcdrive module yet. For example, use mc.WriteObject(0x60A4h, 0h, 1000000) to set the jerk value to 100000000.
NOTE: The jerk setting cannot yet be parameterized via IO input function 4 Timed Motion Absolute or input function 6 Timed Motion Relative.
•When writing 6083h.0h profile acceleration , 6084h.0h profile deceleration is set to the same value. A subsequently changed value for deceleration is only used for stop motion / quick stop with 605Ah.0h quick stop option code 1 or 605Ah.0h quick stop option code 5.
Movingcap Rabbit trajectory generator
MovingCap RABBIT uses the following travel parameters for the travel profiles with point-to-point positioning:
Index |
Subindex |
Type |
Access |
Name [units] |
Description |
607Ah |
0h |
integer32 |
R/W |
target position |
Target position |
6081h |
0h |
unsigned32 |
R/W |
profile velocity |
Maximum velocity |
6083h |
0h |
unsigned32 |
R/W |
profile acceleration |
Maximum acceleration |
60A4h |
0h |
unsigned32 |
R/W |
profile jerk *1) |
Acceleration change / jerk The recommended starting value is, for example, 50x greater than the acceleration - this means that full acceleration is achieved within 20 milliseconds. |
The following boundary conditions are taken into account when calculating the trajectory:
•In order to comply with the specified acceleration limit, the maximum speed is reduced if the travel distance is too short.
•In order to achieve the specified acceleration limit, a low jerk value may be increased to such an extent that at least a pure S-curve (without a constant acceleration phase) is possible.
MovingCap RABBIT control parameters
NOTE: Stable default settings for standard applications are provided ex works for the control parameters, but at least parameter 3101h.04h mass_payload must be set before operation.
NOTE: When a factory reset is performed (e.g. via the Parameters website), the factory default settings are restored and the payload is reset to 0.
Index |
Subindex |
Type |
Access |
Name [Units] |
Description |
3301h |
04h |
unsigned16 |
R/W |
mass_payload [g] |
Additional user/payload weight [g] This is the only parameter that must be set appropriately for each application. The set value does not have to be exact and can also be set higher, for example, to simply increase the stiffness of the static position control. |
3301h |
01h |
unsigned16 |
R/W |
control_mode |
Controller mode / operating mode of the state controller: 2 - Hedgehog - square root position control near the end position, max. end position accuracy. Reduce/prevent overshoot when operating with high loads/additional forces/friction. 3 - Float - tuning mode, only gravity and asymmetry correction is active. |
3301h |
0Eh |
integer16 |
R/W |
deceleration_tuning |
Deceleration/brake tuning [0.1 %], e.g. negative values, e.g. "-300" - use a 30% smaller braking value specification to correct overshooting of the dynamic movement. positive values, e.g. "300" - use 30% more braking force to correct an insufficient dynamic movement. |
3301h |
0Fh |
integer16 |
R/W |
weight_compensation 1*) |
Force pre-control for installation position/weight compensation: -1 - Gravity pulls in a negative direction any other numerical value: Compensation of a force corresponding to the weight of x grams. |
3301h |
08h |
integer16 |
R/W |
k2 err gain |
Controller gain for the integrated (summed) remaining position error in the end position larger values - higher rigidity and accuracy, but less stable / increasing tendency to oscillate |
3301h |
06h |
integer16 |
R/W |
k0 pos gain |
Controller gain for the position difference (linear or root function, depending on operating mode 3301h.01h and size of the position difference) |
3301h |
07h |
integer16 |
R/W |
k1 vel gain |
Controller gain for the speed difference Higher values - correct overshoot / eliminate low-frequency shaking/oscillation in the end position lower values - correct faster resonance/humming in the end position |
1*) To set 3301h.0Fh weight_compensation manually, set 3301h.01h control mode = 3 float, switch on positioning mode and start a positioning run. The drive remains in 'float' mode, but from now on the 3301h.0Fh weight_compensation values are converted directly into force. Use a simple digital luggage scale, for example, to confirm the realized compensation force in the order of magnitude. The force/weight values only correspond approximately to the force actually realized on the motor and are not suitable for measuring applications.
NOTE: Additional calibration/adjustment options are planned as an extension in order to realize a more precise correlation of current and force values.
MovingCap RABBIT motor parameters
Motor parameters are usually set once during drive production. They are retained even after a factory reset and are not reset to a default value.
Index |
Subindex |
Type |
Access |
Name [Units] |
Description |
3300h |
07h |
integer16 |
R/W |
motor_weight 1*) |
The basic weight of the movable motorized carriage |
3300h |
04h |
unsigned16 |
R/W |
motor_imbalance_amplitude 2*) [0.1% of rated current] |
Correction of the phase imbalance / "Torque Ripple Suppression" Amplitude/height of the unbalance in 0.1% of the rated current. I.e. 10 = 1% of the rated current. Corresponds to the scaling of the current/force limitation. |
3300h |
05h |
integer16 |
R/W |
motor_imbalance_angle 2*) |
The mechanical angle of the motor in the range (-180°, +180°) relative to the single-phase point at which the minimum motor current occurs due to the unbalance. |
1*) As with the 3301h.04h mass_payload setting, the value does not have to be exact. The controller always takes into account the sum of 3300h.07h motor_weight and 3301h.04h mass_payload. The following setting is recommended for flatTRACK and FATtrack applications where the motor carriage is fixed and the travel path is movable: Retain the original motor_weight value, and set 3301h.04h mass_payload = total weight of the moving superstructure incl. MovingCap track, minus motor_weight.
2*) The correction values are used for additional operating optimization with the flatTRACK and FATtrack motor variants. The controller also works with the basic setting 3300h.04h motor_imbalance_amplitude = 0. However, the influence of the "torque ripple" can be noticeable during fast movements and the end position accuracy. To determine the appropriate settings manually, use 3301h.01h control mode = 3 float and switch on positioning mode. If possible and taking safety precautions, move the motorized carriage back and forth by hand and look for a repetitive irregularity/pulling force that pulls the carriage slightly into certain positions. Then experiment with a starting value, e.g. 3300h.05h motor_imbalance_amplitude = 20 and different 3300h.05h motor_imbalance_angle settings, until the irregularity disappears completely.
MovingCap CODE - Python programs are currently under development for the automatic execution of calibration runs and automatic determination of the setting values.
Additional parameters for special applications
Additional special parameters and filters can be set for specific applications. Either via a corresponding setup project for Kickdrive, a Python configuration script, or by OW commands via the web interface or terminal/TCP connection. Please contact our support if necessary.
Complete basic initialization, e.g. after repair/conversion
For the complete re-initialization of MovingCap linear drives (flatTRACK, shortTRACK, FATtrack), documented setup projects for use with Kickdrive are available on our movingcap.com service portal, subdirectory Init-Projects. These projects can also be used to re-phase / determine the motor phase position relative to the absolute measuring system.
|
WARNING! These setup projects are also used to rewrite settings for motor overload protection. Only carry out the basic setup after consulting our support team. |
