Recent content by sgb27

Make the tyres from hard plastic rather than rubber.

If speed were linearly proportional to the throttle you wouldn't need a control system! Anyway it sounds like what you are describing to do in code is essentially what a PID controller does. Because PID controllers have been studied a lot (they are used everywhere) there is a lot of...

Certainly the STi OEM headers are unequal length, not sure about the WRX. It's the unequal length headers that give a lot of the characteristic "burble". Really after that the sound is only controlled by a centre resonator (stops drone at highway speeds) and a rear silencer. The stock STi (go...

A few more questions first for the spec. How many times does the device need to work for? Just one 16 hour cycle, or will it be repeatedly refilled? Is the $4 a selling price, production cost or material cost? What about the price/cost of the salt refills? Does the device need to be fixed...

just to add though, a large proportion of the light that is "caught" by the fins will be reflected back up into the unit (it will be much nearer to vertical than the orange line in your diagram) and some of it will come out again at a wider angle, so that keeps the efficiency/overall brightness...

A few things I noticed at first glance: Moment of inertia has units of mass times length squared. So this line: momentOfIntertia += payload.mass * (distCenterOfMass / 100); is wrong, you probably want to be squaring the distance to the centre of mass. Also in your debug text you might want to...

Looking at a typical car engine it seems like the power would only drop down by 10-15% after shifting up a gear, so the *average* power whilst accelerating through the gears up to the red-line is going to be roughly 5-8% down on the peak power. Assuming that this constant average power...

If you can't remember the maths then just do it numerically, in fact I'd recommend that way if you plan to add in later things like torque curves, transmission losses, gear change delays and air drag. Work in small time steps of 0.1 seconds or less, start at t=0. At t=0 you know the velocity...

You need to know the slope angle of the road, the vertical and horizontal position of the car will depend on the slope. If your car has traveled Y(t) up the slope (given by your equations), then that is Y(t)cos(a) horizontally and Y(t)sin(a) vertically, where a is the slope of the road. The...

Your equations are still correct for going uphill, it's just your Y coordinate now points up hill rather than horizontal. To find the actual horizontal and vertical distance you can draw a right-angled triangle to represent the slope, with your "Y" distance going up the hill. You can use the...

So long as the road slope is not to great to cause slipping of the tyres, the path will still be the circle, just at an incline to match the road. You can calculate the new equations for X,Y,Z based on this inclined circle.

What exactly did you try that gave an epicycloid path? If you post your method someone will be able to tell where you went wrong with your working.

The instant the engine makes the wheel rotate faster, the wheel will then be rotating faster than the car so you will have a non-zero slip ratio. This then gives a non-zero coefficient of friction from your chart above and allows the tyre to generate a longitudinal force causing a forward force...

Friction of zero means that whatever the normal load on the tyre, it cannot generate any longitudinal force. Or another way to look at it, in order for the tyre to generate a non-zero longitudinal force the slip ratio must be non-zero.

The slip ratio is (car speed - wheel speed)/(car speed), so when the car and wheels are stopped the slip ratio doesn't really make sense to define. The above graph above will only help you when you know the slip ratio, if not you'll need another graph (maybe someone else measured the static...