YASKAWA ∑ - II Series SGMBH/SGDH AC Servo System

Core functions and parameter configuration

The strength of SGDH drivers lies in their highly configurable internal control algorithms and rich I/O capabilities, which can adapt to diverse application scenarios by setting parameters.

1. Control mode selection

The control mode can be flexibly selected through parameter Pn000.1, mainly including:

Speed control (0): Receive ± 6V to ± 10V analog voltage from the upper computer as a speed reference. The internal speed loop of the drive is completed.

Position control (1): Receive pulse trains (direction+pulse, CW/CCW or 90 ° phase difference two-phase pulse) from the upper computer as position commands. The driver completes position and speed loops internally. The electronic gear function (Pn202, Pn203) can convert input pulses into any mechanical movement distance.

Torque control (2): Receive ± 1V to ± 10V analog voltage from the upper computer as a torque reference. In this mode, the motor output torque is proportional to the input voltage.

Composite mode (3-9, A, B): For example, switching between speed/position/torque modes through external contact signals, or using contact inputs to select preset internal speeds for control.

2. Input/output signal configuration

The input signals (such as servo ON/S-ON, forward/reverse overtravel prohibition P-OT/N-OT, alarm reset/ALM-RST, torque limit/P-CL//N-CL) and output signals (such as servo alarm ALM, positioning completion/COIN, speed consistency/V-CMP, rotation detection/TGON, servo preparation/S-RDY) of the driver CN1 connector can be redistributed and polarity set through parameters (Pn50A-Pn50D, Pn50E-Pn512), greatly improving compatibility with different upper computer systems.

3. Key Function Settings

Electronic gear: By setting Pn202 (numerator) and Pn203 (denominator), the input pulse number can be flexibly converted into the actual rotation angle of the motor, simplifying the calculation of mechanical transmission ratio.

Torque limitation: Internal torque limitation can be set through parameters Pn402/Pn403, or dynamic torque limitation can be achieved through external contacts (/P-CL//N-CL) and analog voltage input (T-REF) to effectively protect mechanical loads.

Overtravel protection (OT): When the P-OT or N-OT signal is triggered, the stop mode can be set through parameter Pn001.1 (such as dynamic braking stop, servo lock after deceleration stop, free sliding stop), and the emergency stop torque can be set through Pn406.

Absolute encoder function: When using a motor with an absolute value encoder, it is necessary to enable it through parameter Pn002.2 and connect the battery (BAT+, BAT -). The auxiliary function Fn008 allows for absolute encoder reset and setting, while Fn013 allows for modification of multi turn limit values.

Debugging and trial operation

To ensure the safe and reliable operation of the system, strict trial operation procedures must be followed.

1. Preparation before trial operation

Safety check: Confirm that all wiring is correct and error free, especially the power line, motor line, and encoder line.

Empty load trial operation (first step): key step. It is necessary to disconnect the motor from the mechanical load (disconnect the coupling) and only allow the motor to run idle. The purpose of this stage is to verify the basic functions of the motor, driver, and encoder.

Use a digital operator to drive the motor in JOG mode (Fn002) and check the rotation direction and smoothness.

Check the status of the input signal (through monitoring mode Un005) and confirm that signals such as servo ON and overtravel are valid.

Check if the motor operates normally without load, and if there are any abnormal noises or vibrations.

2. Load trial operation and automatic tuning (Step 2)

Connect the load: After confirming that the no-load operation is normal, connect the motor to the mechanical load.

Auto tuning (Fn001): The SGDH driver has built-in online auto tuning function. By setting Pn110.0 to "1" (continuous tuning), the driver will automatically recognize the load inertia during actual operation and adjust the speed loop gain (Pn100), integration time constant (Pn101), position loop gain (Pn102), and torque reference filter time constant (Pn401) accordingly to achieve optimal system response. Users only need to select the mechanical rigidity level (1-10 levels, the higher the value, the higher the rigidity) through Fn001, and the automatic tuning will automatically optimize the gain. For systems with minimal load changes, tuning can be set to only occur during the first run.

Save tuning result (Fn007): Save the load inertia ratio (Pn103) calculated by automatic tuning to EEPROM for direct use during the next power on, without the need for re tuning.

Advanced Adjustment and Optimization

For applications that pursue ultimate performance, the system response can be optimized by manually adjusting the servo gain.

Basic gain adjustment principle: The servo system consists of a current loop, a velocity loop, and a position loop in order from the inside out. The response speed of the inner loop must be higher than that of the outer loop. Therefore, to increase the position loop gain (Pn102), it is necessary to first increase the velocity loop gain (Pn100). If the position loop gain is set too high and the velocity loop cannot keep up, it will cause velocity reference oscillation and prolong the positioning time.