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1) Can you have diferent tension levels aplied to a lego motor, for speed control purposes ? Or, one can only make it turn at a constant speed. 2) Are there more precise rotation sensors than the ones that came with lego mindstorms (only 16 ticks (...) (23 years ago, 25-Apr-02, to lugnet.robotics)
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| | Re: Control lego motors and rotation sensors
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(...) You can set a power level, but it doesn't seem very effective at controlling speed. (...) Usually you just gear it up so that it spins faster. If you're gearing down a motor to drive a wheel or an arm, arrange to put the rotation sensor (...) (23 years ago, 25-Apr-02, to lugnet.robotics)
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| | Re: Control lego motors and rotation sensors
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(...) There are commands for the RCX to use different 'power levels' - which will translate into a change in speed if there is sufficient load. (...) lego (...) No - but you can use a gear train to make the rotation sensor spin more than once for (...) (23 years ago, 26-Apr-02, to lugnet.robotics)
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| | Re: Control lego motors and rotation sensors
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Changing the motor 'speed' (pulse wave modulation) really only changes the torque. It will only change the speed if the motor is heavily loaded. Another technique that is more successful is to create a control loop in which the motor is on for 5 (...) (23 years ago, 26-Apr-02, to lugnet.robotics)
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| | Re: Control lego motors and rotation sensors
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(...) That's not really any different from what the RCX's firmware does though. You are doing pulse-width modulation and so does the firmware. The only difference is that you are using a longer time-constant. ---...--- Steve Baker ---...--- Mail : (...) (23 years ago, 26-Apr-02, to lugnet.robotics)
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| | Re: Control lego motors and rotation sensors
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(...) The standard firmware does pulse-width modulation alternating between ON and FLOAT. What I think Jerry is suggesting is pulse-width modulation alternating between ON and BRAKE (which does control speed quite handily, and is what legOS does). - (...) (23 years ago, 26-Apr-02, to lugnet.robotics)
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| | Re: Control lego motors and rotation sensors
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Wow! I hope LegOS has the option to use On and Float too. I was planning on migrating to LegOS soon, but if it does On and Brake, it is to be avoided. That technique simply burns battery power! JB (...) (23 years ago, 26-Apr-02, to lugnet.robotics)
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| | Re: Control lego motors and rotation sensors
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(...) Oh, it probably does have that option; if nothing else, you can change the code to do it that way. I simply find the ON/BRAKE modulation to be more useful, so haven't bothered looking for an alternative. - Alex (23 years ago, 26-Apr-02, to lugnet.robotics)
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| | Re: Control lego motors and rotation sensors
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(...) The 'on-brake-on' method of speed control is VERY useful. When implemented it looks and acts like a stepping motor. For an example, go to my website at (URL) and navigate to my Injection Molding Factory. There is a motorized air valve with a (...) (23 years ago, 26-Apr-02, to lugnet.robotics)
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| | Re: Control lego motors and rotation sensors
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(...) I'm not so sure about motor design, there are quite a few motors that block (one in ten for me). Since wou use RoboLAB it may rather be the LEGO firmware that protects your motors, it contains code to limit the speed of switching the motor. (...) (23 years ago, 27-Apr-02, to lugnet.robotics)
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