Patent ID: 9206026
Filing Date: 2015-12-08
Classification: B66F

Abstract:
1. A method of monitoring longitudinal stability for a lift vehicle using a longitudinal stability system, the lift vehicle including a vehicle chassis supported on front and rear wheels respectively coupled with a front axle and a rear axle, and a boom pivotally coupled to the lift vehicle, the method comprising: (a) monitoring, with a load sensor, a vertical load on the rear axle; and (b) managing, with a machine controller, boom lift down speed based on the vertical load, wherein upon a determination of anticipated operator demand for boom lift down, step (b) is practiced by: the machine controller setting the lift down speed to a low speed parameter; the load sensor and the machine controller determining whether the rear axle load stays above a first value for a certain period of time, and when so, ramping up the lift down speed to a high speed parameter, and when not, maintaining the lift down speed at the low speed parameter; and the load sensor and the machine controller determining whether the rear axle load becomes less than a second value, and when so, ramping down the lift down speed to a creep speed or stop parameter.