Currently, there is still a gap between domestic and foreign products in terms of robot reaction speed and precision. The key to solving this problem lies in the core component of robots—the servo motor. The development of robots in China is rapid, especially in the field of industrial robots. However, there is still a gap between domestic and foreign products in terms of robot reaction speed and precision. So, what is the key point? Below, the technical staff from Huichuan Servo Motor's official website will explain:
The key lies in the robot's core component—the servo motor. During operation, the robot achieves multi-degree-of-freedom motion through the drive of servo motors. If high speed and precision are required for the robot's movements, then the servo motor's response speed and control precision must be sufficiently high.
In actual robot operation, servo motors are often in various acceleration, deceleration, forward and reverse states, which places high demands on the servo motor's short-term overload capability, inertia adaptation range, frequency response bandwidth, and speed/torque response time.
One of the most important metrics is frequency response bandwidth, which determines how fast the servo system responds to commands and is a key metric for robot designers.
Definition of servo motor frequency response bandwidth: The maximum sinusoidal frequency that a servo system can respond to is the frequency response bandwidth of that servo system. In more professional terms, it is the frequency at which the amplitude frequency response decays to -3dB (-3dB bandwidth), or the frequency at which the phase frequency response lags by 90 degrees.
More specifically, the Ministry of Machinery Industry standard "General Technical Conditions for AC Servo Drives" (JBT10184-2000) specifies the test method for servo drive bandwidth: The driver inputs a sinusoidal speed command with an amplitude of 0.01 times the rated speed command value. The frequency gradually increases from 1Hz, and the corresponding motor speed curve is recorded. As the command sinusoidal frequency increases, the phase lag of the motor speed waveform relative to the command sinusoidal curve gradually increases, while the amplitude gradually decreases. The frequency at which the phase lag increases to 90 degrees is taken as the bandwidth of the servo system at a 90-degree phase shift; the frequency at which the amplitude decreases to 0.707 times the low frequency is taken as the -3dB bandwidth of the servo system.
In short, the faster the frequency response bandwidth, the more timely the servo system can respond to rapidly changing instructions. Even if the movements of an industrial robot are complex, it can respond in a timely manner and drive the position of each joint of the robot to be in place.
