I want to know how to represent a coffee machine using a Deterministic finite automata?
I've tried a lot to do this job.
I represented each and every processes as a set,by putting one to one correspondence with Natural numbers.
But I still don't know how to represent it using DFA.
First, try to imagine the states your automaton can be in. Something like:
Off, Ready, Working
Afterwards imagine the buttons or inputs you have to perform to switch between these states. Do not forget to define every input on every state. If you leave out several transitions, the automaton is not deterministic therefore is an NFA. Transitions could be:
0 for power off/on
1 for start/stop working
Off -0-> Ready
Ready -1-> Working
Ready -0-> Off
Working -1-> Ready (4 for the actual working process)
Off -1-> Off
Working -0-> Working (nothing happens in this cases)
Just connect the states with the given transitions, and voilá!
Related
I have three inputs in merge signals in different time, the out put of merge signals appeared to wait for all signals and outputted them. what I want is to have an output for every signal (on current output) as soon as it inputted.
For example: if I write (1) in initial value. 5,5,5 in all three numeric. with 3 sec time delay, I will have 6,7,and 16 in target 1, target 2, and target 3. And over all 16 on current output. I don't want that to appear at once on current output. I want to have as it appears in target with same time layout.
please see attached photo.
can anyone help me with that.
thanks.
All nodes in LabVIEW fire when all their inputs arrive. This language uses synchronous data flow, not asynchronous (which is the behavior you were describing).
The output of Merge Signals is a single data structure that contains all the input signals — merged, like the name says. :-)
To get the behavior you want, you need some sort of asynchronous communication. In older versions of LabVIEW, I would tell you to create a queue refnum and go look at examples of a producer/consumer pattern.
But in LabVIEW 2016 and later, right click on each of the tunnels coming out of your flat sequence and chose “Create>>Channel Writer...”. In the dialog that appears, choose the Messenger channel. Wire all the outputs of the new nodes together. This creates an asynchronous wire, which draws very differently from your regular wires. On the wire, right click and choose “Create>>Channel Reader...”. Put the reader node inside a For Loop and wire a 3 to the N terminal. Now you have the behavior that as each block finishes, it will send its data to the loop.
Move the Write nodes inside the Flat Sequence if you want to guarantee the enqueue order. If you wait and do the Writes outside, you’ll sometimes get out-of-order data (I.e. when the data generation nodes happen to run quickly).
Side note: I (and most LabVIEW architects) would strongly recommend you avoid using sequence structures as much as possible. They’re a bad habit to get into — lots of writings online about their disadvantages.
Im working on running traffic lights on four cases by using case structure and Flat-sequence structure. For example, there is green light on first case, and the rest of the three cases should have red light. As soon as the first case approaches to red light, the second case moves towards the green light. All these are controlled by specific time delays. The flat sequence structure is running the traffic lights properly in all the four cases, but, when I insert case structure, it only runs one case and does not activate the other cases. How can i make the VI run all the four cases simultaneously??
First off, this is an old CLD exam. There should be a wealth of examples available from a quick search. That said, some suggestions: never use a flat-sequence structure. Ever. Instead you need to use some combination of a state machine and subVIs. NI has a prep kit for the CLD (below). Check it out, it’ll show you what a state machine is in LabVIEW and how to take advantage of subVIs.
http://www.ni.com/gate/gb/GB_EKITCLDEXMPRP/US
i'm developing a 2d game , rts game, is sort of like COC (Clash of Clans). cool mobile game,huh. but i run into some problem with path-finding, as usual,i do path-finding algorithm once every agent was placed somewhere in screen by finger-touch,but in some case, this incur performance penalty, and your mobile phone will be very hot as your agents increase suddenly and simultaneously.
actually,no matter what path-finding i use,e.g a*,dijkstra, or something special(maybe optimal),which is always time-comsuming process throughout the whole game loop ,especially massive agents on less powerfull mobile cpu. as far as i know, some game like this, shortest path is not the focus (will people care about the path agent walk through intentionally?) instead of efficient and naturally path-finding. so my mind come up with some solutions,maybe impractical.
solution 1 : use some cheaper path-finding algorithm, could be graph related or somethingelse because shortest path doesn't matter.
solution 2 : put some limits on ai module to process agent for path-finding, e.g upper limit to path-finding algorithm calls at interval,that is,just one or two agents of the those agents got planning, let rest of them plann after several game frames. as you know ,its drawback is obvious.
the above is what i thougt. hope your game dev disciplined guys give me brilliant idea , tricks, i'll appricate. thank you very much.
EDIT:
here is my related pseudo code,and procedure cresspond to my game logic.
//inside logic thread
procedure putonagent
if (need to put agent on world space)
//do standard a* path-finding for an agent
path_list=do_aStar_path_finding(attacktargetpos,startpos);
and then enqueue path_list;
......
end
the path_list's queue finally used by visual agents for stepping forward. any hints?
Look up "Hierarchical pathfinding" Say you're driving to a city far away, you don't plan the entire path before you get in the car!
Pathfinding is usually done in steps, like it's not one function call, after N iterations it'll return (and indicate it's not complete) so it can be run at the next available time. Basically rather than a function with locals think operator() and state variables as members of a class.
To make it fast you can make the heuristic crap with A* pathfinding, suppose I use a heuristic of 10* the distance-as-the-crow-flies, it may not find the shortest path but it will have a strong preference for heading towards the target rather than "fanning out" and exploring further around the closed region.
I don't know what the differences are between a transition diagram and finite automata. When I google for 'transition diagram', I get state diagrams as a result.
Is there a difference between transition diagrams and finite automata? Or is finite automata a form of transition diagrams?
Thanks.
A transition diagram is a way of visually representing finite state machines. It's kind of on the borderline between flowcharts and source code; it contains enough information to completely describe the finite state machine, but when implementing FSMs on a computer, we generally use other representations that are easier for the computer to process.
A transition diagram for DFA, is a graph shows moment or transition
between states For each state in Q there is a node represented by the
circle.3 main components are initial state,final state and inputs
. Finite machine . It is an abstract machine shows finite number
of states it is the simplest machine to recognize patterns.
Hope this will be helpfull for you.
Finite Automata is a machine where you feed the machine with some input and the machine produces a respective output(Mealy Machine, Moore machine) or no output at all(Deterministic Finite Automata, Non Deterministic Finite Automata) depending on the machine.
Whereas, a transition diagram is used to show the transition from one state to another which is used by all of the above machines. For Example transition from Q1 (initial state) to QF (Final state).
A finite automaton (FA) as name implies Finite number of states
is a simple idealized machine used to recognize patterns within input taken from some character set (or alphabet) .
The job of an FA is to accept or reject an input string depending on whether that string being accepted by FA or not.
whereas ;
Transition daigram can be interpreted as a flowchart for an algorithm recognizing a language ; show the transition form one state to other after recieving input strings consists of three things:
A finite set of states, at least one of which is designated the start state and some of which are designated as final states
Im am working on a VHDL project that includes an fsm.
Some states change according to a counter. It dit not work until i put 'clk' in the sensitivity list, besides the current state and the input.
I know that during synthesis, the sensitivity not used, or discarded. But how can that have such an impact on the result in the simulation? if a leave this 'clk', would the fsm perform as i want op an FPGA?
thanks,
David
This is the simple explanation:
The simulator uses the sensitivity list to figure out when it needs to run the process. The reason why the simulator needs hints to figure out when to run the process is because computer processors can only do one (or only a few in multicore systems) thing at a time and the processor will have to take turns running each part of your design. The sensitivity list allows simulation to run in a reasonable time frame.
When you synthesize code into an ASIC or FPGA, the process is always "running" since it has dedicated hardware.
When you simulate a state machine without the clock in the sensitivity list, the process will never run on the clock edges, but only on changes to your input. If you have the state transition implemented as a flip flop (if clk'event and clk = '1') then your state transition will never be simulated unless you happen to change your input at the same time as the clock's rising edge.
You should probably leave the clock in the sensitivity list, assuming the FSM changes on clock edges.
Also, try to proofread your questions.
Synthesis tools focus on logic design (FPGA, ASIC) and ignore sensitivity lists because there are only three basic types of logic: Combinational logic, edge sensitive storage (flip-flops and some RAM), and level sensitive storage (latches and some RAM).
Combinational logic requires all input signals to be on the sensitivity list. From a synthesis tool perspective, if one is missing, they can either ignore the sensitivity list and treat it as if all inputs were on the sensitivity list, or produce some complicated combination of flip-flops and combinational logic that probably will not do what the user wanted anyway. Both of these have an implementation cost to the vendor, hence, why invest money (development time) to create something that is not useful. As a result, the only good investment is to simplify and ignore the sensitivity list.
Simulators on the other hand, have a bigger perspective than just logic design. The language defines sensitivity lists as to indicate when the code should run. So simulators implement that semantic with a high fidelity.
Long term it may make you happy to know that VHDL-2008 allows the keyword "all" to be used in a sensitivity list to replace the signal inputs there. This is intended to simplify the modeling of combinational logic. Syntax is as follows:
MyStateMachine : process(all)
begin
-- my statemachine logic
end process MyStateMachine ;
Turn on the VHDL-2008 switch and it out in your synthesis tool. If it does not work, be sure to submit a bug against the tool.