# Tag Info

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Conceptually everything was set up correctly, but a number of basic mistakes affected the signal. Here is the set-up which should be used to record the signal from one of the encoder outputs: A set up like this should result in a a clean signal if your motor/encoder is not broken. Once it's up and running, seeing the signal is simple. It's as easy as ...

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Besides referring to the previously-mentioned 82860502 pdf file, see pages 30 and 31 of Steven Engineering's 44MICRO-MOTORS.pdf file, where the following diagram appears and shows the usage of the brown, yellow, and blue wires. Attach a V+ voltage (for example, 5VDC) to the brown wire and connect the blue wire to ground. As the motor rotates, the yellow ...

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EKF sensor fusion is achieved simply by feeding data streams from different sensors to the filter. So all you need to do is setup your implementation to accept both encoder and IMU data. This is basically a matter of providing different versions of the observation model matrix $\mathbf{H}$ that converts states to sensor measurements, one for each sensor. It'...

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I assume you mean hobby servos, like the one pictured here: These were primarily designed for RC planes and cars to actuate control surfaces and steering. Continuous rotation is not needed. So a simple and cheap potentiometer is used for absolute position measurement. Cheap pots like this have a large dead zone. Their internal construction is something ...

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Good job writing a test program that shows lots of data -- that's an excellent first step in figuring out what's going on. With two physical motors, there is always going to be at least a little internal difference between them -- slightly different internal winding resistance, slightly different internal bearing friction -- which is often negligible ...

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You're likely getting something analogous to "contact bounce". When you slowly rotate the wheel, there are regions where channel A is Lo for a while, then channel A is Hi for a while. While it would be nice if the Arduino only saw one low-to-high transition between those regions, often a encoder will oscillate a few or a dozen times during the brief period ...

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Encoders These are quadrature encoders. Quadrature encoders have two sensors that look at a rotating wheel with black and white bins alternating in regular intervals (or magnetic sensors looking at alternating magnets). These two sensors are shifted relative to each other, so that when one looks at a center of one bin, the other is precisely at the edge ...

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I followed the link to your Reddit post and, after checking the datasheet for your motor, I agree with what some people are saying there, but I'll expand their answers and hopefully give you some insight into what I think is happening. /u/zevryn said, I hope this doesn't come off as mean since I'm not trying to be, but how good are you with the ...

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Since it's the wheels which change the robot's pose in the environment, I'd suggest putting the encoders to the wheels. Especially if the motor and the wheel are only connected by a chain, introducing possible slack between motor and wheel angular positions. Would the wheel sit directly on the motor axis, it would not matter.

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If you are talking about an encoder that would be used on a motor, an encoder is the device that encodes the position of the motor into a particular format, so used to determine the exact physical position of the motor at any one time, where as an ESC or Electronic Speed Controller is used to actually drive the motor to a different speed. Generally speaking,...

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ServoCity 624 RPM Premium Planetary Gear Motor w/Encoder has the encoder on the motor and a 19:1 gear reduction on the output shaft. Mechanical tolerance in the gearbox accounts for the difference between 228 counts per revolution that I expected and 230.7 counts per revolution that I measured.

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A PID controller takes an error as input (the encoder ticks) and yields an output whose unit of measurement $O$ (the PWM percentage, usually) is uncorrelated with the unit of measurement $I$ of the input. To this end, the PID gains $K_P$, $K_I$, and $K_D$ do have units of measurement: $[K_P] = \frac{O}{I}$ $[K_I] = \frac{O}{I \cdot s}$ $[K_D] = \frac{O \... 1 First, you need to find out how the encoder is used in your system. There are two sketches of plugs, I assume your encoder is connected as shown in the upper sketch. Since the company who produced this is still producing and selling encoders, website here, I would start by giving them a call. First of all ask, if they can provide a drop in replacement. It ... 1 As @jsotola guessed in the comments, it is possible you have magnetic interference between your motors and hall effect encoders. This exact thing happened to me on a very compact electo-mechanical design for a robot hand seen here. If I remember correctly, we wanted to keep our magnetic encoders so we moved the motors farther away. But you might be able ... 1 The code you provide is only to give you example on how 2 arduino communicate using I2C protocol. You will need to modify it so it can fully work as intended. You can modify it so Arduino Mega can send command to Arduino Uno and Arduino Uno can send sensor data to Arduino Mega When using I2C communication, you need common ground, so connect both arduino ... 1 To measure position more accurately you need to use all three. They are used for choosing which motor phase to energise, which is called commutation. Searching for "6 step commutation" will give you lots of diagrams and info on how to estimate position this way. 1 If it is the same type of shaft coupling as the one in the picture, as long as the set screw is completely on the motor shaft, it will transfer adequate torque. To help with the limited clearance, ensure no pulling force is apply to the coupler since it might slip out of the coupler. The motor shaft and the coupled rod must perfectly straight to reduce the ... 1 What kind of motors are you using? Because the behaviour you describe makes me think of a brushless motor, due to the fact that you have a rotating magnetic field having the rotor spin. But in the beginning it will not necessary start on the right direction (during a very very little lapse of time). Your program's frequency can also be related to this ... 1 Welcome to Robotics, Ahmed. You have posted the code you use to build the encoder counts, but not the code you used to display the counts. I mention this because you have the encoder counts displayed in your post as: 13786.00 13938.00 as in, with a trailing decimal, but your encoder counts are defined in your code to be integers. This could be ... 1 I am looking into this type of absolute position encoder. They were used in the NAO robot. They are small, accurate and typically under$10 USD.

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Different encoders will attach to the motor or shaft differently. Typically, the motor has a small shaft coming out the back of motor for this purpose. And you buy the motor with the encoder already installed. Actually, now i see you asked about a brushless motor. Typically, these have added hall effect sensors by the manufacturer. Because you ...

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Using a Kalman filter will definitely work to estimate velocity. However you will not be able to estimate position with accuracy. This is because the position is unobservable with just encoders and an optical flow sensor. You will still be able to estimate position but the uncertainty will be unbounded.

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I doubt you will be able to simply by something an attach it. How to make an encoder will depend on how this motor is used. Are you doing a chain, gears? You will need to design the rotation sensor into the rest of the power transmission system. What you do is place a disk of some kind, plastic or metal and then you make a hole or slot in the disk and ...

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Any of them. Which ones have you looked at? I googled, and the first one that came up was a smaller pololu unit for a micro robot, But you know what? They all work the same and are fairly simple to build / adapt. You probably can locate a hall effect sensor at the 13 tooth sprocket. Understanding Integrated Hall Effect Rotary Encoders Other than that, ...

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