Hot answers tagged

9 votes

Control both Velocity and Position (Linear actuator)

The first thing to realise is that this is not a control problem, this is a planning problem. If you conflate the two, you are making life much more complex than it needs to be. Solution - Motion ...
user avatar
  • 4,098
8 votes
Accepted

Can I control more than 18 servo motor with a Raspberry Pi

Raspberry Pi has only one hardware PWM channel and Linux distribution it runs is not a real time system, so software PWM may be very unstable. You are not guaranteed, that your program will be ...
user avatar
  • 953
6 votes
Accepted

Which micro-controler/processor to be used for autonomous stereo vision robot system?

Stereo vision and SLAM are pretty heavy algorithms, both in terms of the processing power and RAM required. You can forget about running this on a little microcontroller like an Arduino. These run at ...
user avatar
  • 6,337
6 votes
Accepted

Modeling a robot to find its position

Assuming a constant update of 5Hz, your sample time is (1/5) = 0.2s. Get one position of the target, p1. Get a second position of the target, p2. Target speed is the difference in position ...
user avatar
  • 14.7k
5 votes

Raspberry Pi for two wheel robot?

A Raspberry Pi should be sufficient for the control you intend to do with it. In designing a controller under a full multitasking operating system, like the Linux operating systems that are available ...
user avatar
5 votes

What mechanical parts can be attached to DYJ48 stepper motor?

You can drill a hole to match the shaft into whatever it is and either fix it with a setscrew against the flat or glue it. Or you could glue a brass tube (hobby shop) to the shaft if you can find one ...
user avatar
5 votes
Accepted

What is the required theory behind building a robotic arm?

There are 2 (or 3, depending on how the planned lifetime of the robot is) thing thats you have to consider. Static load: The motors stall (zero revolution) torques have to be able to hold the weight ...
user avatar
  • 6,412
5 votes
Accepted

Length and Width of a Line Following Robot

Actually, the caster wheel has ideally no effect on the kinematics of the vehicle. In reality there will be some resistance from the caster wheel that does impact the vehicle motion, but we can still ...
user avatar
  • 1,357
5 votes

Best sensor to determine "up" versus "down"

if you aren't moving, the accelerometer will give you the direction of gravity. if you are moving and hoping to use this orientation data for control you'll need to incorporate at least one more ...
user avatar
  • 1,825
5 votes
Accepted

Arduino or Raspberry Pi?

For interfacing with a camera, I would recommend the Pi. The reason is that the AVR in the Arduino is an ordinary processor, whereas the Broadcom SoC in the Pi was originally designed for multimedia. ...
user avatar
  • 321
5 votes
Accepted

12 volt input to 5 volt ouput of Arduino

Nobody can tell how much magic smoke is still in the device. You need a magic smoke detector (rarely also referred to as a "voltmeter"), hook one of its contacts up to the pin that should have 5 volts ...
user avatar
5 votes
Accepted

Will this pseudocode work as a basis for a flight controller?

The signals to the ESC's using PWM should be sent after the PID algo is done processing the errors. The output calculated from the PID is the PWM value to be sent to the ESC's to actuate the motors in ...
user avatar
5 votes

Alternatives to Kalmam Filter

A good choice for sensor fusion with the MPU6050 is a second order complementary filter, which I used for the orientation estimation in a project. The complementary filter is computational cheap and ...
user avatar
5 votes
Accepted

Why to combine a Raspberry Pi (or similar board computer) and an Arduino for controlling motors?

The reason is Clock on the Raspberry Pi. Note that the raspberry is powerful but not that powerful that it can run an OS and simultaneously give you precisely timed PWM outputs. I assume that you'll ...
user avatar
4 votes

Outputting a precise voltage in millivolts on Arduino Mega

analogWrite() does not support a higher range of duty cycle. However the timers on the AVR chip do support higher precision/resolution, so you can bang the registers directly, especially if you don'...
user avatar
  • 720
4 votes
Accepted

Arduino Power Supply

There are two main ways to power an Arduino: with 5 volts and with 6.5 to 12. Since your case falls under the 6.5 to 12 option there are two main ways you can get power into an arduino. The barrel ...
user avatar
  • 420
4 votes

Can't Read current on Pololu Dual MC33926 Motor Driver Shield for Arduino

When there is miscommunications between the microcontroller and a chip, assuming the electronics are not damaged, there could be a couple of things that can go wrong. Of course, further diagnosis is ...
user avatar
  • 3,210
4 votes
Accepted

12V compressor and air pressure control

Whether a single 3-way, 2-position pneumatic valve (typically with a work port, an input port, and an exhaust port ‒ see page 3 of nationalpneumatic.com's pdf about valves) will suffice depends on ...
user avatar
4 votes

How would i go about learning to code a flight controller?

Controlling a flying robot (or anything else) is a very complex subject (well, people are doing PhD on it..). I can recommend this free online course on the subject (I have taken it myself). It will ...
user avatar
4 votes

Sporadic sensing rates for hc-sr04 ultrasonic distance sensor

You said, "on some occasions the sensor will read values consistently (at maybe 20 vals per second)". 20 values per second is 20Hz. This means that you are polling every 50ms. In the datasheet ...
user avatar
  • 14.7k
4 votes

How to make a robot move using Arduino other than timing to predefined locations?

Cartesians Robot use sensors. All robot need sensors. Sometime they are external (camera looking at the robot), sometime they are on the robot (IMU). Basically what you're asking is : How can an ...
user avatar
  • 561
4 votes

Can I control more than 18 servo motor with a Raspberry Pi

You need a controller like this that can address them individually over I2C. These can be chained together to control more than you'll likely ever need: Adafruit 16-Channel 12-bit PWM/Servo Driver - ...
user avatar
4 votes
Accepted

Arduino mega shield v2.0 compatibility with arduino due

It should be possible to plug that shield into either a Due or a Mega, with the caveat that the URF01 pins on the shield may interfere with two sockets of the Power header (IOREF and the opening next ...
user avatar
4 votes
Accepted

Robot path planning

You have to know your initial heading, let's call it $\theta_0$. So you start at some position, $p_{start}$, and you're trying to get to some end position, $p_{end}$. Assume starting position and ...
user avatar
  • 14.7k
4 votes

What exactly are PPM controlled ESCs? Are most ESCs available to build quadcopters PPM Controlled?

I believe there is confusion about these terms. Strictly speaking, the ESC is PWM controlled. Although the signal usually gets there from a transmitter and receiver signal that is PPM encoded. It ...
user avatar
  • 1,027
4 votes

How to have a 'Auto Go Home' feature, like the DJI Phantom 3, on a project built quadcopter?

I would go with one of two-ish methods to do this, but both methods require the craft to know its own position. You could do this with GPS, or an IMU, or any other means or combination of position ...
user avatar
  • 14.7k
4 votes
Accepted

Need super-basic help with motor encoder

The "Green (Ground), Brown (Channel B), Yellow (Channel A), and Orange (Sensor Voltage +)" wires connect to the encoder on the back of the motor and allow the use of quadrature to detect the number ...
user avatar
4 votes

Should I use an arduino to control my balancing robot's motors?

If you want to have a good balancing, PID loop timing is very important. Standard Raspberry OS, like Raspbian can't guarantee you any precise timing, so once your loop period may be 10ms, once it can ...
user avatar
  • 953
4 votes

Balance Bot PID tuning

Just a hint from my extensive experience from self balancing robots: The most important aspect of a self balancing robot, is the actuator acceleration (torque) control. (...) the motors start ...
user avatar
  • 71

Only top scored, non community-wiki answers of a minimum length are eligible