The gain switching function is only effective in position and speed control mode and can be triggered by the internal state of the servo or external DI. Using gain switching can have the following effects:
When the motor is enabled to be stationary, the position latched state can be switched to a lower gain to suppress vibration and reduce static noise;
During the motor stop process, when the position is set, it can be switched to a higher gain to shorten the positioning time;
It is possible to switch to a higher gain during motor operation to achieve better command tracking performance;
Different gain settings can be switched through external signals based on the load device situation.
Give an example:
In the application scenario of LED die bonder, there is a demand for high-speed, high-precision and high response servo, which is a typical application of fast positioning P2P. The gain switching function is adopted to ensure fast setting requirement and reduce the noise when the servo is enabled to be stationary.
| Parameter group | Steps for gain switching adjustment | Not using gain switching, adjust the gain manually | The second gain is set the same as base gain | Enable gain switching function | In static state, adjust the first group of gain parameters, eliminate static noise | |||
| P06 | Velocity proportional gain 1 | 35.0Hz | 27.0Hz | |||||
| P06 | Velocity integral gain 1 | 16.00ms | ||||||
| P06 | Position proportional gain 1 | 63.0Hz | ||||||
| P07 | Torque filtering 1 | 0.65ms | 0.84ms | |||||
| P06 | Velocity proportional gain 2 | 35.0Hz | ||||||
| P06 | Velocity integral gain 2 | 16.00ms | ||||||
| P06 | Position proportional gain 2 | 63.0Hz | ||||||
| P07 | Torque filtering 2 | 0.65ms | ||||||
| P06 | Gain switching - Mode selection | 0 | 1 | |||||
| P06 | Gain switching - Condition selection | 10 | ||||||
| P06 | Load inertia ratio | Obtained by inertia identification |
SV3 servo supports the following 10 gain switching methods, including 1 external DI switching and 9 switching methods upon internal motion status of the servo:
0: The first gain is fixed (PS)
1: Use external DI for switching (PS)
2: Torque instruction (PS)
3: Speed instruction (PS)
4: Speed instruction change rate (PS)
5: High/low speed threshold of speed instruction (PS)
6: Position deviation (P)
7: With position instruction (P)
8: Positioning is incomplete (P)
9: Actual speed (P)
10: With position instruction + actual speed (P)
Herein, (P) represents that that switching method only supports position control mode; (PS) represents that the switching method supports both position control and speed control modes. Below is the detailed instructions about the 9 internal switching methods of the servo.
| Gain switching method | Switching method change diagram |
| 2: Torque instruction | |
| 3: Speed instruction | |
| 4: Speed instruction change rate | |
| 5: High/low speed threshold of speed instruction | |
| 6: Position deviation | |
| 7: Position instruction | |
| 8: Positioning is completed | |
| 9: Actual speed | |
| 10: With position instruction + actual speed | Combination of method 7 and method 9 is generally chosen to ensure fast and stable setting in place |
The delay time '06-12h' is only valid when the second gain is switched into the first gain.
| 0x2006- Gain class parameter | ||||||
| Subindex | 0x10- Gain Switching - Mode Setting | 0x11- Gain Switching - Condition Selection | 0x12- Gain Switching - Delay | 0x13- Gain Switching - Level | 0x14- Gain Switching - Time Delay | 0x15- Gain Switching - Time |
| Data type | UINT16 | |||||
| Accessibility | Readable/writable | Readable/writable | Readable/writable | read-only | read-only | |
| Unit | - | - | ms | - | - | ms |
| Default | 1 | 0 | 5.0 | 50 | 30 | 3.0 |
| Min. | 0: The first gain fixed, use external DI for P/PI switching 1: Switching between the first gain and the second gain is valid, and the switching condition is P06.16 |
0: The first gain fixed (PS) 1: Switching by external DI (PS) 2: High torque instruction(PS) 3: High speed instruction(PS) 4: High change rate of speed instruction(PS) 5: Speed instruction high/low speed threshold (PS) 6: Large positional deviation (P) 7: With position instruction (P) 8: Positioning is uncompleted (P) 9: Actual speed (P) 10: With position instruction+actual speed (P) |
0 | 0 | 0 | 0 |
| Max. | 1000 | 20000 | 20000 | 1000 | ||
| Setting and effective mode | Run settings/Effective immediately | Run settings/Effective immediately | Stop setting/immediate enable | Stop setting/immediate enable | Stop setting/immediate enable | Stop setting/immediate enable |
| Related mode | - | |||||
| Note | - | |||||