What To Do If The Servo Does Not Rotate Smoothly? Here Are Some Tips To Make The Servo Run More Smoothly.

I believe that when you are playing with robots or doing maker projects, you have encountered the situation where theservorotates one after another. I originally wanted the robotic arm to move gracefully, but instead it danced like a stuck robot, which was really annoying to watch. Smoothly adjusting the rotation of theservois not only the key to improving the quality of the work, but also the basis for achieving precise control. Today we are going to talk about how to make theservorotate smoothly.

What are the causes of steering gear vibration?

The steering gear does not rotate smoothly, which is often caused by unstable signals or insufficient power supply. Just like a person who is hungry and has no energy to work, if the voltage of the steering gear fluctuates greatly or the current supply is insufficient, the torque output by the motor will be uneven, which will be manifested as jitters. Especially when multiple servos are working at the same time, the power requirements are higher, and ordinary USB power supply cannot be used at all.

Another common cause is that the refresh rate of the control signal is too low. Many friends directly use the delay function to control the change of the servo angle, which will cause the signal to be updated late. The control chip inside the servo receives intermittent instructions, and naturally cannot smoothly transition from one angle to another. It looks like a frame skip.

How to choose the appropriate power supply for the steering gear

The choice of power supply is directly related to the performance of the servo. Small servos such as SG90 require 5V voltage and hundreds of milliamps of current for normal operation. If they are directly powered by a computer USB port, they will easily restart or jitter when encountering strong resistance. It is recommended to use an independent regulated power supply module, or directly connect a 2S lithium battery to power the servo through a voltage-reducing module.

For high-torque servos, such as those with metal teeth, the instantaneous current may reach more than 2A. At this time, ordinary dry batteries in battery boxes cannot hold it at all, and the voltage will be pulled down instantly. Be sure to use a power lithium battery or a high-power switching power supply, and in the circuit design, separate the steering gear power supply and the control circuit power supply to avoid interference.

How to achieve smooth transition in code

Code is the soul of achieving smooth rotation. Don't just let the servo jump from 0 degrees to 180 degrees, but divide this journey into many small steps. For example, if you want the servo to turn around within 2 seconds, you can increase the angle by 1 degree every 10 milliseconds, so that the servo will move along a gentle arc instead of ejecting instantly.

Of course, simply walking step by step is not enough. We can also add acceleration and deceleration algorithms. Let the servo accelerate slowly when starting, and then slow down slowly when approaching the target, just like driving a car. This can effectively avoid overshoot and jitter caused by inertia. Especially when the servo is loaded, the optimization effect of acceleration and deceleration will be very obvious.

What kind of steering gear has better performance?

If you find that the servo still shakes despite optimizing the program and power supply, it may be a problem with the hardware itself. The analog servo maintains its position by continuously sending PWM waves, and the holding force itself has a slight jitter. The digital servo has a built-in processing chip, which has faster response speed, better holding power, and naturally turns more smoothly.

In addition, the gear accuracy of the steering gear is also critical. Plastic gears will have empty positions after being used for a long time, resulting in inaccurate rotation. The coreless motor combined with the metal gear steering gear not only has a long service life, but also has small gear clearance and small mechanical vibration during rotation. If your budget allows, just use a servo with double ball bearings, and you will definitely be satisfied with the smoothness.

Does the installation structure have a big impact on rotation?

The smoothness of the servo not only depends on itself, but also on how you install it. If there is interference in the structural parts connected to the servo arm, or if the screws are tightened too much and cause the housing to deform, the running resistance of the internal gear of the servo will increase. In this case, the servo will keep struggling to reach the target position, producing high-frequency sizzling sounds and jitters.

Be sure to ensure that the installation surface of the servo is flat and the fixing screws must be moderately strong. The connected linkage should move freely without any jamming. Many times, we blame the problem on the steering gear. In fact, as long as the mechanical structure is readjusted and the steering gear is given a relaxed environment to exert force, it will immediately return you a smooth movement.

How to debug to achieve the best results

Debugging is a patient job. You can first use a simple program to let the servo swing back and forth between 0 degrees and 180 degrees, and then gently pinch the servo arm with your hand to feel the strength. If there is obvious graininess or vibration, it means that either the voltage is not enough, or the delay setting in the code is unreasonable.

If possible, you can use an oscilloscope to see whether the waveform of the control signal is regular. But at home, a more practical approach is to change different PWM frequencies to test. Usually 50Hz is the standard frequency, but some servos perform better at higher frequencies. Try several sets of parameters to find the set of data that is most suitable for your servo. The whole process is like customizing it.

Having said so much, in fact, making the servo run smoothly is nothing more than providing sufficient power, writing the program, selecting the hardware, and installing the structure. I wonder if you have ever encountered a particularly difficult problem of servo vibration when working on a project? How was it resolved in the end? Welcome to share your experience in the comment area, and let’s communicate and make progress together. If you think this article is helpful to you, don’t forget to like and share it with more friends!