Hi,

For position control, I recommend using DC high-torque servo motors, you can just look for the maximum torque you need because this affects the weight, price, and power consumption. You can use it with modern digital devices (controllers PCs etc). You can easily control it using some ready codes with a resolution of 1 degree. You can modify the codes or design some circuits to obtain an even better resolution. Also, be aware of the time response since there is a quite small delay in command execution to reach the reference position. Be aware that some servos are designed for speed control, not position.

Alternatively, you can look for AC servos and stepper motors, it depends on the size, weight, price, power rate, control, required torque/force of the device according to your application.

Hello,

One option would be to keep the pneumatic actuation, with a multi-position cylinder (a combination of two cylinders) in order to implement the neutral gear (high speed, high force, super-easy to control, maintenance free, lightweight), but it needs the compressor unit and air storage buffer.

Another option would be to have an "electrical cylinder" which is actually (best option for your needs) a linear synchronous 3 phase AC (tubular) servo-motor. It offers speed, precision and high force, but it needs a specific digital drive and most likely some inverter 12V to 230V (for the drive).

The above are best suited if you still have the shifting rod and want to keep it. Otherwise you could rely on the previous answer, but mos likely this will force you to select or design a mechanical transmission for the motor (which will slow things down), because the torque you need is quite high for direct drive (~10Nm).

If you are concerned with shifting speed and lightweight the best compromise is still pneumatic actuation.

As Valentin suggested you may be able to still use pneumatic cylinders, in fact even the standard push pull cylinder can be made into a multi position. They usually have magnets in the cylinder head so you can tell where there are. You could combine simple read switch sensors with a solenoid valve to release all gas pressure (from both halves of the cylinder) when the required position has been reached.

Otherwise I would recommend looking at stepper motors rather than servos. They are much simpler to control and give you a high toque for each step. Usually for a servo motor, you need to carefully ramp up the speed and the controlling is somewhat more complicated. The only real advantage of a servo is that the current it takes is proportional to the torque, so you can tell when it gets stuck for example. You can however "miss steps" with a stepper motor, as there is no inherent feedback, you need to make sure the motor has more than enough torque, otherwise when you tell the motor to "step", it simply judders! Stepper motors are much easier to get hold of, and come in a wide varied of powers and sizes, including geared. For a quick start, you could have a look for some online kits using the "A4988" chip, and an Arduino or Atmel AVR controller. If you are getting into the control of things, i cant recommend the Atmel AVR microcontrollers (ATmega etc.) enough, a really fantastic platform!