Electric Bikes - potential field of application for magnetic encoder sensors

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WU_Student
05-03-12, 01:07 AM
Dear all,

In the course of a project headed by the University of Business and Economics Vienna, we are looking for potential application fields of a magnetic encoder.

Basically the technology allows measuring the position of a magnet.

Can you imagine a field, where for instance one or several of the following problems occur;

• Positions have to be measured contactless
• Extreme external conditions (dust, other magnetic fields, temperature, vibrations) have to be passed over
• Maintenance is difficult due to the high complexity of the final product/application
• Linear, rotating or three-dimensional positions have to be measured
• The space is limited and expensive
• It is vivid to avoid/know about malfunctions of position tracking systems
• Easy implementing and catch/use of the signal is necessary
• An energy effective solution is important.

We were able to identify the drive system as a potential field of application. To be precise, the sensors, which control the power of the electro motor, show (according to various interviewees) several weak spots. This could be e.g.: imprecise responding behaviour of the sensors which prevents the driver from controlling the e-motor properly, necessity of calibrating the sensors after change of tyre or chain, sensors which are heavily affected by dirt an therefore have to be cleaned or exchanged regularly, usage of antiquated gearshift equipment…

Please let us know if you experienced any of the above mentioned or other problems in the past. It would be of great help for us!

Thank you very much!


dhiltonp
05-03-12, 08:57 AM
I don't really understand what you're trying to ask (though I'm pretty sure it doesn't apply to me, being a fairly new ebiker).

Perhaps you could reword this?

WU_Student
05-04-12, 12:45 AM
Basically we are trying to find out, if e-bikers encounter any problems concerning the drivetrain of their e-bikes. This could possibly be: need of calibration of the sensors/motor after change of the chain/tyre, vulnerability against dirt and therefore necessity of cleaning exchanging the sensors...

So if you could think of any problem concerning the drivetrain when using your e-bike, please let us know


AllenG
05-04-12, 08:24 AM
What sensors are you referring?
I have no idea how one would even begin to calibrate a motor.

dhiltonp
05-07-12, 10:50 AM
Custom-built ebikes usually are throttle-based without sensors in the drive system.

Commercial ebikes usually meet top-speed requirements by sensors or just by having a small motor. Commercial systems are usually well sealed and I've never heard of anyone having sensor-based issues with their ebikes (well, except for BionX owners wanting to disable the assist limit).

WU_Student
05-08-12, 11:50 PM
Thank you all for your replies!

@AllenG
Systems which are based on strain gauges to measure the applied torque of the cyclist face these issues. However, our sensors are not able to measure torque.

@dhiltonp
Thank you for your reply, should anything else, concerning e-bike sensors, come to your mind, feel free to share!

AllenG
05-09-12, 01:54 AM
Thank you all for your replies!

@AllenG
Systems which are based on strain gauges to measure the applied torque of the cyclist face these issues. However, our sensors are not able to measure torque.

Gotcha, like the Panasonic system. I've had no issues since 2005. I would like to know how to build a torque sensor throttle with off the shelf parts.