Presets
Playback
Ground, machine and driver
The throttle and brake are held at the set percentage. The loader climbs only if the tyre-gravel friction beats the grade plus rolling resistance; with a raised, loaded bucket the centre of mass moves forward and up and the static tip angle falls.
Bucket
Model checks
The science
What is modelled
One-dimensional motion along the grade. The engine torque curve and gear ratio give a drive force, capped by the friction limit of the tyres and by the engine power at speed. Gravity along the slope, rolling resistance, air drag and the brake oppose the motion. The combined centre of mass depends on the bucket height and load, and gives the static tip angle.
Equations
m a = Fdrive - m g sinθ - crr m g cosθ - ½ ρ CdA v|v| - Fbrake.- Grip limit:
|Fdrive| ≤ μ m g cosθ, so climbing needsμ cosθ > sinθ + crr. - Friction circle:
Flong = √((μN)² - Flat²). - Static tip angle:
atan(half base / height of the centre of mass).
Checks run in the page
- Downhill acceleration -g sin(theta) at rest.
- Braking distance on the flat against v squared over 2a.
- The grip rule against simulated climbs.
- The friction circle on a 3-4-5 triangle.
Honest simplifications
A point-mass longitudinal model with a fixed brake deceleration that is not limited by tyre grip, a simple engine curve, a prescribed gravel ripple for the suspension and a static tip-over estimate that ignores dynamic effects. Not a machine-safety calculation.
What to try
- Press Wet gravel: with a friction coefficient of 0.1 the machine slides back even at full throttle.
- Press Steep grade: the climb is limited by engine power rather than by grip.
- Press Heavy raised bucket and watch the tip-angle margin shrink.