Examples brought from the participants of the class
Machine states: why and how?
Robots are taking important roles in our lives. We saw in a previous class the Kiva Robots . There are many social implications and these are not the only ones used in warehousing. But also it is part of our course to understand how these machines operate and are using the sensors to guide themselves through the shelves.
We discussed about the impact of introduction of robotics, but somehow we left outside all the new opportunities that this brings to the game. Some robots are specifically designed to interact with other workers. For example, Baxter has many degrees of freedom and also has a human form factor to move precisely and while helping on tedious tasks. But of course there are many other improvements in hazardous environments like the car industry.
What would happen if the car is in the function of self driving and a door is opened? There should be a way to establish these different behaviors…
Related topic: Why self driving cars must be programmed to kill
Finite State Machine
A finite–state machine (FSM) or finite–state automaton (plural: automata), or simply a state machine, is a mathematical model of computation used to design both computer programs and sequential logic circuits. It is conceived as an abstract machine that can be in one of a finite number of states.
Here there is an interesting example of how a state machine can be used in automation (robot joke?)
Read further: Why developers should use state machines ?
Using the concept of function and state machine, we created in class our very humble autonomous LDR/LED system. Code is hosted in Github: here
Review: Bits and Bytes
What can we do with FSM?
Just another example:
From other robot fans we can learn more about their state machines and the functions they use them for.
Using the basic work frame given in Example 7, we can build a state machine with several inputs and different actions. For this we define 4 different scenarios:
- environmental light
- strong light on the left sensor
- strong light on the right sensor
- strong light on both sensors
Instead of using real motors, we are using LEDs to simulate the states.
See it working with two LDR’s (simulator)
We connect the real motors with the functions, such as an example.
Code example is hosted here: Example
A complex behavior as a set of sub-behaviors