DBW and safety control.

Discussion and support for MoTeC's previous generation ECUs.

DBW and safety control.

Postby Polux RSV on Mon Mar 05, 2018 11:07 pm

Hi,
I am putting DBW throttles on a bike

My questions, for the software guys, are: what are the behaviors of the DBW control when the following situation append:

- one track of a sensor fail ?
Does the control continue, relying only on the other track and issuing an warning?
Does it close the throttle?
Does it disable the driver to let the throttle go to limp mode ?

- both tracks of a sensor fails ?
Does it try to close the throttle ?
Does it stop the motor, whith potential risks?
Does it disable the motor (going to limp) ?

- Sensors tracks are in range, but motor seems stuck
Does it stop or disable the motor ?
Does it try to close the throttle, at full or partial PWM ?

Regards

Angelo
Polux RSV
 
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Re: DBW and safety control.

Postby MarkMc on Tue Mar 06, 2018 8:49 am

Hello Angelo,
If there is any type of control issue the throttle body control will be stopped and the engine rev limiter set to the Fail Safe RPM Limit.

The M800 will not control the throttle body without all 4 channels, TP, TP2, TPD and TPD2 working correctly.

The sensors must all agree with each other and the throttle must track the aim position within tolerance. If you go into the diagnostic errors screen (press F3) and then press F1 for the help you will see the more detailed explanation of each of the diagnostics for DBW.

The M1 ECU will allow the use of only one throttle sensor and one pedal sensor but if any sensor drop out during use the throttle control will be turned off until the driver releases the pedal so there is no requested position and the ECU will reset the error and continue to drive the throttle, this can be done while driving without an ECU reset or the engine turning off. The M800 will require all sensors to be fixed and the ECU needs to be reset for any errors.
MarkMc
 
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Re: DBW and safety control.

Postby Polux RSV on Thu Mar 08, 2018 6:50 pm

Hi,
MarkMc wrote:The M800 will not control the throttle body without all 4 channels, TP, TP2, TPD and TPD2 working correctly.


If I understand correctly, as soon as one track of the sensor pair fails, the control stops, and safe RPM limiter is set. There is no tentative to continue with the track which seems correct ?

I am not a specialist of safety, and I could be wrong, but can I say this implementation is worst than having only one TP and one TPD for the control? :?:
If control stops at first failure, having twice the sensors will double the risk that my race will stop before the finish line. :cry:

If I am correct, I will use only one track of the dual sensors, and connect the corresponding second input at the M800 connector side.

Angelo
Polux RSV
 
Posts: 90
Joined: Wed Feb 18, 2009 4:18 am

Re: DBW and safety control.

Postby David Ferguson on Fri Mar 09, 2018 1:42 am

That is very unsafe -- please to not do that. Get proper sensors that are reliable enough to not stop your race!
David Ferguson
Veracity Racing Data
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Re: DBW and safety control.

Postby MarkMc on Wed Mar 14, 2018 10:31 am

The system will only work with all sensors in working order, this has been quite reliable for the best part of 17 years. As Dave said you must make sure your sensor system is good quality with good wiring and you will be fine. If there is a problem a power cycle of the ECU will get you going again as long as everything is working.

The M800 is a reflection of the theories at the time and the M1 is much better at deciding what is a fault and how to deal with it. The M1 can work on one sensor if one fails but this functionality will not be added to the M800.
MarkMc
 
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