Whilst playing around with my servo controller I realised that the power used by a servo goes up considerably when it's under heavy load (such as when it's pressing against the table and still trying to move). I can, potentially, get an idea of this load by measuring the current that each servo is using and using this feedback somehow. I've yet to work out how, but at the very least it could be used to protect the servos against overloading; if the load gets above a certain threshold then stop moving! Ideally the servo controller could feed this information back to the user of the servo controller as well. Anyway, this requires quite a large amount of breadboarding changes, the use of some active low multiplexor chips and some playing around with the ADC on the ATMega. I don't think I'll experiment with this just yet...
Recently in Sensors Category
I saw these Dynamixel DX servos mentioned on Trossen Robotics this morning, see here. They're interesting because they have a richer interface than the normal hobby servos that I've been looking at and they provide a multidrop RS485 interface so that you can chain multiple servos together and control them individually via a single line. You can get feedback on the angular position, velocity and torque and also alerts if temperature and voltage deviate from expected (user specified) ranges. I expect that the torque feedback would be useful to help with determining if the foot is in contact with the ground and also should enable you to detect if the leg is being obstructed during movement which should make moving over uneven surfaces easier to program. All of this wonderfulness is not without a price though, these babies are around $200 each...
