I am new here and looking for one linear actuator with capability of motion control(e.g. constant driving speed) and force sensing for the mechanical impedance test of one passive mechanism. Here is my general requirements:
The linear actuator is capable of driving the system at a constant speed (or accurate motion/speed control) under changing reaction load from the system.
The linear actuator is designed with embedded force sensing device installed, which means the reaction forces between the actuator and the driven system can be measured in real-time.
I noticed that there are Concentric linear actuator with feedback, which is compatible with jrk motor controller available in Pololu. I still have several questions before ordering.
What’s the objective of the controller, i.e. my request of constant driving speed with respect to different load can be achieved or not?
Concentric linear actuator is the only one that can work with the controller here or other manufacture’s products also fine? I am asking this because it seems that there is force sensing function of the concentric actuator.
This is the first time I post here, please let me know if there is anything not right. Looking forward to your reply. Thanks
Hello. The objective of the jrk controller is to drive the motor so that the Feedback (the position of the actuator) reaches the Target (specified by you). That’s what the PID algorithm does. The jrk does not have any built-in speed control for this type of system, but you can control the speed by slowly changing the Target. For example, you could connect a computer to the jrk and send a steady stream of Set Target commands with slowly changing values.
No. The jrk will generally work with actuators that have a DC motor and can produce an analog voltage that represents the position of the actuator. We sell linear actuators from different manufacturers and they all work with the jrk.
Thanks for your reply with patience. Can I ask one more question about the force sensing of the linear actuator? I have searched the linear actuator that works compatible with the jrk control board and there seemed to have none with the force sensor embedded. The reaction force sensing capability is one important requirement of my test. Do you have any suggestions with this?
That is correct; our linear actuators do not have force sensors built in. The jrk can sense the current being drawn by the actuator, and that will be an indication of the force, but I am not sure if the jrk’s current sensing capability will be accurate enough for you. You could attach your own, more accurate current sensor to the system and read it with a microcontroller. Alternatively, you could install a force sensing resistor on the actuator and read it with a microcontroller.
