Whats the best algorythm for steering with the gyro that steers less the faster you go

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fubarpk

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Posted: 26th Nov 2018 10:04

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Quote: "I am really after a good algorithm for understeer/oversteer using the gyro"

at the moment im just thinking if I was heading down a straight fast the car might understeer a little
that way it wouldn't be so touchy as you was going fast down the track and you would have to slow
and steer allot more to make a corner. Im not sure if I have the wrong idea here but not sure of the
algorithm I should apply

BY DEFINITION

UNDERSTEER
It means lack of grip. When this happens, the driver will have little response from the steering wheel.
It takes place when the vehicle’s front wheels begin to plow straight despite turning the steering wheel.
Front-wheel-drive cars are prone to this phenomenon because they send the engine power to the wheels that steer the car. So, when the tires start, the driver does not feel any grip to steer.
It most commonly happens due to accelerating early while turning in a corner. You lift the weight distribution that takes the control off of the front tires and leads to understeer.
It can also occur when you turn the wheels on your car too fast and too far.
Applying more suspension or increasing front wing can minimize the understeer. Tire pressure adjustment also helps sometimes.
OVERSTEER
It happens when the front side of a vehicle has more grip than the back side. It makes the car to spin when driving into a corner.
Oversteer is the result of the rear end of a car being fishtailed or sliding out.
Rear-wheel-cars are susceptible to oversteer because here the rear end of the car has the control power. So, when the rear end loses the grip, it overtakes the front and oversteer occurs.
Oversteer is not something to be concerned over because it happens in everyday driving. However, it could be dangerous if occurs in snowy, muddy, or rainy conditions.
You have to do the opposite to fix this problem. You have to loosen the suspension or downforce to drop the grip.

Thanks for any feedback/help/suggestions etc

fubar

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smallg

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Posted: 26th Nov 2018 11:18

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Work out your speed as a % of your top speed then adjust the steering by that.
You may want to adjust the result a bit to ensure it feels more accurate but it's probably the easiest and smoothly transitions with speed changes.

I.e. top speed is 100
Current speed is 30
30/100 = 0.3
Because we want slower speeds to be better turning we adjust our % to invert the value
1 - 0.3 = 0.7
Max Steering is 5
5 * 0.7 = 3.5

So we would turn at 3.5 instead of 5.

The only issue is that at top speed we would be unable to turn so you will likely want to adjust the value to ensure it never gets below a certain value.

life's one big game
spec= i5 4ghz, 16gb ram, Nvidia 1070ti gpu

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fubarpk

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Posted: 26th Nov 2018 16:59 Edited at: 26th Nov 2018 17:51

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Thanks smallg

Playing with that I get

// Project: steeringTest 
// Created: 2018-11-17

// show all errors
SetErrorMode(2)

// set window properties
SetWindowTitle( "Steering test" )
SetWindowSize( 1024, 768, 0 )
SetWindowAllowResize( 1 ) // allow the user to resize the window

// set display properties
SetVirtualResolution( 1024, 768 ) // doesn't have to match the window
SetOrientationAllowed( 1, 1, 1, 1 ) // allow both portrait and landscape on mobile devices
SetSyncRate( 30, 0 ) // 30fps instead of 60 to save battery
SetScissor( 0,0,0,0 ) // use the maximum available screen space, no black borders
UseNewDefaultFonts( 1 ) // since version 2.0.22 we can use nicer default fonts
#constant KEY_LEFT  = 37  //the left arrow key scancode
#constant KEY_UP    = 38  //the up arrow key scancode
#constant KEY_RIGHT = 39  //the right arrow key scancode
#constant KEY_DOWN  = 40  //the down arrow key scancode
#constant AccelerationFactor#=.025 //the speed your car accelerates at
#constant DecelerationFactor#=.025 //the braking factor
#constant maxSteering#=1
#constant maxCarSpeed#=100  
#constant minCarSpeed#=0.01

CreateSprite(1,0)
SetSpriteSize(1,50,50)
SetSpritePosition(1,512,400)
x#=512
do
	
	if GetRawKeyState ( KEY_UP )
		carSpeed#=carSpeed#+((maxCarSpeed#-carSpeed#)*AccelerationFactor#) //increase the car speed every 1 second
		if carSpeed#>maxCarSpeed# then carSpeed#=maxCarSpeed#
    elseif GetRawKeyState ( KEY_DOWN ) 
		carSpeed#=carSpeed#-((maxCarSpeed#-carSpeed#)*DecelerationFactor#+.01) //+.01 otherwise it doesnt decelerate if top speed reached
		if carSpeed#<minCarSpeed# then carSpeed#=minCarSpeed#
    else 
		//carSpeed#=carSpeed#-((maxCarSpeed#-carSpeed#)*DecelerationFactor#+.01) //+.01 otherwise it doesnt decelerate if top speed reached
		//if carSpeed#<minCarSpeed# then carSpeed#=minCarSpeed#
    endif
    xx#=0
    if GetDirectionX()>0
		xx#=maxSteering#+(GetDirectionX()-(carSpeed#/maxCarSpeed#))
	endif
    x#=x#+xx#
	
	SetSpritePosition(1,x#,GetSpriteY(1))
	Print(GetDirectionX())
    print("Speed="+str(carSpeed#))	
    Print("Xpos "+str(x#))
	sync()
loop

+ Code Snippet

// Project: steeringTest 
// Created: 2018-11-17

// show all errors
SetErrorMode(2)

// set window properties
SetWindowTitle( "Steering test" )
SetWindowSize( 1024, 768, 0 )
SetWindowAllowResize( 1 ) // allow the user to resize the window

// set display properties
SetVirtualResolution( 1024, 768 ) // doesn't have to match the window
SetOrientationAllowed( 1, 1, 1, 1 ) // allow both portrait and landscape on mobile devices
SetSyncRate( 30, 0 ) // 30fps instead of 60 to save battery
SetScissor( 0,0,0,0 ) // use the maximum available screen space, no black borders
UseNewDefaultFonts( 1 ) // since version 2.0.22 we can use nicer default fonts
#constant KEY_LEFT  = 37  //the left arrow key scancode
#constant KEY_UP    = 38  //the up arrow key scancode
#constant KEY_RIGHT = 39  //the right arrow key scancode
#constant KEY_DOWN  = 40  //the down arrow key scancode
#constant AccelerationFactor#=.025 //the speed your car accelerates at
#constant DecelerationFactor#=.025 //the braking factor
#constant maxSteering#=1
#constant maxCarSpeed#=100  
#constant minCarSpeed#=0.01  

CreateSprite(1,0)
SetSpriteSize(1,50,50)
SetSpritePosition(1,512,400)
x#=512
do
	
	if GetRawKeyState ( KEY_UP )
		carSpeed#=carSpeed#+((maxCarSpeed#-carSpeed#)*AccelerationFactor#) //increase the car speed every 1 second
		if carSpeed#>maxCarSpeed# then carSpeed#=maxCarSpeed#
    elseif GetRawKeyState ( KEY_DOWN ) 
		carSpeed#=carSpeed#-((maxCarSpeed#-carSpeed#)*DecelerationFactor#+.01) //+.01 otherwise it doesnt decelerate if top speed reached
		if carSpeed#<minCarSpeed# then carSpeed#=minCarSpeed#
    else 
		//carSpeed#=carSpeed#-((maxCarSpeed#-carSpeed#)*DecelerationFactor#+.01) //+.01 otherwise it doesnt decelerate if top speed reached
		//if carSpeed#<minCarSpeed# then carSpeed#=minCarSpeed#
    endif
    xx#=0
    if GetDirectionX()>0
		xx#=maxSteering#+(GetDirectionX()-(carSpeed#/maxCarSpeed#))
	endif
    x#=x#+xx#
	
	SetSpritePosition(1,x#,GetSpriteY(1))
	Print(GetDirectionX())
    print("Speed="+str(carSpeed#))	
    Print("Xpos "+str(x#))
	sync()
loop

as you see tho it still needs work

fubar

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smallg

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Joined: 8th Dec 2005

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Posted: 26th Nov 2018 18:43

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try this

// Project: steeringTest 
// Created: 2018-11-17
 
// show all errors
SetErrorMode(2)
 
// set window properties
SetWindowTitle( "Steering test" )
SetWindowSize( 1024, 768, 0 )
SetWindowAllowResize( 1 ) // allow the user to resize the window
 
// set display properties
SetVirtualResolution( 1024, 768 ) // doesn't have to match the window
SetOrientationAllowed( 1, 1, 1, 1 ) // allow both portrait and landscape on mobile devices
SetSyncRate( 30, 0 ) // 30fps instead of 60 to save battery
SetScissor( 0,0,0,0 ) // use the maximum available screen space, no black borders
UseNewDefaultFonts( 1 ) // since version 2.0.22 we can use nicer default fonts
#constant KEY_LEFT  = 37  //the left arrow key scancode
#constant KEY_UP    = 38  //the up arrow key scancode
#constant KEY_RIGHT = 39  //the right arrow key scancode
#constant KEY_DOWN  = 40  //the down arrow key scancode
#constant AccelerationFactor#=.025 //the speed your car accelerates at
#constant DecelerationFactor#=.025 //the braking factor
#constant maxSteering#=10
#constant maxCarSpeed#=100  
#constant minCarSpeed#=0.01  
 
CreateSprite(1,0)
SetSpriteSize(1,50,50)
SetSpritePosition(1,512,400)
x#=512
do
    if GetRawKeyPressed(27) then end  
    if GetRawKeyState ( KEY_UP )
        carSpeed#=carSpeed#+((maxCarSpeed#-carSpeed#)*AccelerationFactor#) //increase the car speed every 1 second
        if carSpeed#>maxCarSpeed# then carSpeed#=maxCarSpeed#
    elseif GetRawKeyState ( KEY_DOWN ) 
        carSpeed#=carSpeed#-((maxCarSpeed#-carSpeed#)*DecelerationFactor#+.01) //+.01 otherwise it doesnt decelerate if top speed reached
        if carSpeed#<minCarSpeed# then carSpeed#=minCarSpeed#
    else
        carSpeed#=carSpeed#-((maxCarSpeed#-carSpeed#)*(DecelerationFactor#*0.24)+.01) //+.01 otherwise it doesnt decelerate if top speed reached
        if carSpeed#<minCarSpeed# then carSpeed#=minCarSpeed#
    endif
    xx#=0
    if GetDirectionX()<>0
        xx#=maxSteering#*(GetDirectionX()*(1-(carSpeed#/(maxCarSpeed#*1.1))))
    endif    
    x#=x#+xx#
    SetSpritePosition(1,x#,GetSpriteY(1))
    Print(GetDirectionX())
    print("Speed="+str(carSpeed#))  
    Print("Xpos "+str(x#))
    sync()
loop

+ Code Snippet

// Project: steeringTest 
// Created: 2018-11-17
 
// show all errors
SetErrorMode(2)
 
// set window properties
SetWindowTitle( "Steering test" )
SetWindowSize( 1024, 768, 0 )
SetWindowAllowResize( 1 ) // allow the user to resize the window
 
// set display properties
SetVirtualResolution( 1024, 768 ) // doesn't have to match the window
SetOrientationAllowed( 1, 1, 1, 1 ) // allow both portrait and landscape on mobile devices
SetSyncRate( 30, 0 ) // 30fps instead of 60 to save battery
SetScissor( 0,0,0,0 ) // use the maximum available screen space, no black borders
UseNewDefaultFonts( 1 ) // since version 2.0.22 we can use nicer default fonts
#constant KEY_LEFT  = 37  //the left arrow key scancode
#constant KEY_UP    = 38  //the up arrow key scancode
#constant KEY_RIGHT = 39  //the right arrow key scancode
#constant KEY_DOWN  = 40  //the down arrow key scancode
#constant AccelerationFactor#=.025 //the speed your car accelerates at
#constant DecelerationFactor#=.025 //the braking factor
#constant maxSteering#=10
#constant maxCarSpeed#=100  
#constant minCarSpeed#=0.01  
 
CreateSprite(1,0)
SetSpriteSize(1,50,50)
SetSpritePosition(1,512,400)
x#=512
do
    if GetRawKeyPressed(27) then end  
    if GetRawKeyState ( KEY_UP )
        carSpeed#=carSpeed#+((maxCarSpeed#-carSpeed#)*AccelerationFactor#) //increase the car speed every 1 second
        if carSpeed#>maxCarSpeed# then carSpeed#=maxCarSpeed#
    elseif GetRawKeyState ( KEY_DOWN ) 
        carSpeed#=carSpeed#-((maxCarSpeed#-carSpeed#)*DecelerationFactor#+.01) //+.01 otherwise it doesnt decelerate if top speed reached
        if carSpeed#<minCarSpeed# then carSpeed#=minCarSpeed#
    else
        carSpeed#=carSpeed#-((maxCarSpeed#-carSpeed#)*(DecelerationFactor#*0.24)+.01) //+.01 otherwise it doesnt decelerate if top speed reached
        if carSpeed#<minCarSpeed# then carSpeed#=minCarSpeed#
    endif
    xx#=0
    if GetDirectionX()<>0
        xx#=maxSteering#*(GetDirectionX()*(1-(carSpeed#/(maxCarSpeed#*1.1))))
    endif    
    x#=x#+xx#
    SetSpritePosition(1,x#,GetSpriteY(1))
    Print(GetDirectionX())
    print("Speed="+str(carSpeed#))  
    Print("Xpos "+str(x#))
    sync()
loop

life's one big game
spec= i5 4ghz, 16gb ram, Nvidia 1070ti gpu

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fubarpk

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Years of Service

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Joined: 11th Jan 2005

Playing: AGK is my friend

Posted: 26th Nov 2018 22:43 Edited at: 27th Nov 2018 15:30

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Oh yes thanks that works quite well

and if you change

+ Code Snippet

if GetDirectionX()<>0
        xx#=maxSteering#*(GetDirectionX()*(1-(carSpeed#/(maxCarSpeed#*1.1))))
    endif

to

+ Code Snippet

    if GetDirectionX()<>0
        xx#=maxSteering#*(GetDirectionX()*(1-(carSpeed#/(maxCarSpeed#*1.1))))
        SetSpriteAngle(1,GetSpriteAngle(1)+xx#)
    endif

It really demonstrates what I wanted and possibly a hint into how this could be achieved in 3D
Thanks Again

fubar

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