Sorry for waiting so long to answer. We're having problems with our email server... Well, I think I will use Murata gyros. I've found a lot of linear acceleration sensors, piezoelectric, mass-balance, MEMS, etc. from differ= ent manufacturers, but only found Murata and Tokin to make small (chip size), "low cost" gyros. I thought that I was missing something. The other gyros in consideration are CRS-03 from Silicon Sensing Systems, UCG-1, UGA-1, UDG, USCR from CFX Technologies and GyroChip models from BE= I, but all of them are a little on the big size for my project. We are developing a math model (167 variables and equations, aprox.) for = a 1/4 size car, same as the "big" one. The math model will be onboard next year, being part of a stability control system. But now we are trying to know how good is our math model. And here is where the 6DOF system goes. = I hope we can get accel and speed with at least 9 bits over the spected ful= l range (+-5g linear and, perhaps, +-180=BA/sec angular). We are measuring wheel angular speed as well. Each wheel has a (inox) bra= ke disk with 32 ventilation holes. This holes are detected whith inductive proximity sensors, directly linked to the 16F877. There are 4 RC servos to control the 4 wheel brakes, 1 servo for steering and another one for the throttle. This servos are directly connected to t= he PIC, and are controlled with (10 bits resolution) PWM pulses. The PIC wil= l talk to a remote PC via a (RS2) RF link to program specific manoeuvres (t= his part isn't done yet). =BFtoo much for a single PIC? ;-)) Thanks again, Alvaro. ----- Mensaje original ----- De: Brandon Fosdick Para: Enviado: s=E1bado, 31 de marzo de 2001 6:27 Asunto: Re: [EE]: Linear and angular acceleration sensors > The Murata sensors don't seem to be much better than the Tokin sensors, > at least accoring to the data sheet. 20% variation over the operating > temperature range, 5% non-linearity, and a scale factor of only > 0.67mV/deg/sec. With that scale factor the signal to noise ratio is > going to be a problem and you'll need a temperature sensor too. Althoug= h > I guess it really depends on how accurate you want you're IMU to be. If > you do go with these gyros I'd be curious to see what kind of results > you get. > What kind of application are you designing for? > > -Brandon > > "Sean H. Breheny" wrote: > > > > We also made a 6 DOF inertial measurement unit using 3 Analog Devices > > ADXL105's and 3 Murata ENC-03J rate gyros. It works pretty well, and = we are > > happy with the Murata gyros. Why did you reject them? > > > > Sean > > > > At 08:15 AM 3/30/01 -0500, you wrote: > > > > I'm looking for sensors to measure linear and angular acceleratio= n and/or > > > > speed. I'm trying to do a low cost, remote 6 DOF data acquisition based on > > >a > > > > 16F877. > > > > > > > > The triaxial ADXL series from Analog Devices seems good to measur= e linear > > > > accel, but I don't know how to get the angular measures. Do you k= now a > > >good > > > > source for this kind of sensors? > > > > > >One of our current projects is doing exactly what you mentioned. I think we > > >are using accellerometers from Analog Device and gyros from Murata. Sorry, > > >I'm not the guy picking these particular components. > > > > > > > > >******************************************************************** > > >Olin Lathrop, embedded systems consultant in Littleton Massachusetts > > >(978) 742-9014, olin@embedinc.com, http://www.embedinc.com > > > > > >-- > > >http://www.piclist.com hint: The PICList is archived three different > > >ways. See http://www.piclist.com/#archives for details. > > > > -- > > http://www.piclist.com hint: The PICList is archived three different > > ways. See http://www.piclist.com/#archives for details. > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads