How do I design circuits for robots?

Question

How do I design circuits for robots?

Answer 1

First, you must learn the dynamics of robotics.   Without an understanding of the robot's kinematics and an ability to express those kinematics mathematically, you will lack the language required to express the robot's movements as part of a transfer function that can be incorporated into an electronic control system.

Second, you must learn electronic controls.   This is a specific area of electrical engineering.   This will allow you to relate the circuit elements to the mathematical expressions described by the kinematics, and allow you to provide for proper feedback in your design.

It would also be beneficial to study embedded systems, if you wish to incorporate a PIC controller in your design.

Answer 2

The same way you design any other circuits. You make a list of requirements, then using experience and other info, find circuits that fit those requirements.

Something as complicated as a robot, the requirements will be broken down into sections, one for each board or supply or other assembly, with each having a set of requirements (inputs, outputs, power, accuracy, dimensions, etc).

Answer 3

This depends greatly on what sort of robot you are attempting to build and on what scale. The robot's environment also plays a large role. I work in a large robotics lab with many different types of robot each with their own type of circuit.

If you are thinking of building a small mobile robot that will drive around on flat ground (i.e a 2d environment) then you do not need to know the dynamics of the system.

If you are looking at creating a large articulated robot (the types used to build cars) then you need the dynamics. These are a set of equations used to model the motion of your robot. For anything with more than 2 motors these are very complicated and require you to use lots of maths. Really the dynamics live inside a computer program though, not in the circuit.

Generally, if you are a building a robot for a hobby or college project I would say don't bother with the dynamics. Just use more powerful motors! Use a microcontroller like a PIC or Arduino to control DC motors (for a robot on wheels) or Servo motors (for a robot's arms). There is plenty of free code for both of these devices but the Arduino is easier for a beginner (and the circuit comes pre-built, you just plug in your sensors and actuators - it is also VERY cheap!)

If you are controlling DC motors you will need to build a driver circuit using a transistor like the TIP120 (a microcontroller can't generate the current to drive the motor)

If you are controlling servos you can hook the control lead directly to the output pin of your microcontroller. Servos are great because you tell the motor what angle you want it to go to and it will hold that position even if you push against it (or put a weight on the arm it is connected to).

Now just connect some sensors. You can make some bump sensors out of switches. You now have to write some code to make the robot do something i.e. 'when the switch turns on drive in the other direction.' You can upload this onto your microcontroller through your USB port.

Of course it is possible to make a circuit for a robot without a microchip but these robots tend to either be very complicated to build (and hard to fix when something goes wrong) or too simplistic to do anything really interesting. Look into BEAM robotics for some really simple robots.

Have fun :-)

Answer 4

Asimov who had a great interest in robots and knew physics very well had to invent the "posatronic" brain to even write about a viable robot. Robotics is in its infancy and the logical step is to develop a single purpose device with some kind of limited decision ability. A car that can decide what it needs to do to avoid an obstacle (like a Roomba) or that can recognize and climb stairs. An airplane that can stabilize itself. Etc.