Patent ID: 8332119
Filing Date: 2012-12-11
Classification: B60T,B60W

Abstract:
1. A system for a hill descent control HDC in the braking equipment of a motor vehicle comprising; an electrically controllable service brake system that includes a brake regulator configured to provide an output signal a_R; a brake actuator connected to the brake regulator and that receives the brake regulator output signal, the brake actuator permitting individual adjustment of at least one of braking pressures p_RAD,i and braking moments generated for individual wheels (i) of a motor vehicle, which are respective manipulated variables controlled by the hill descent control HDC, with the control of the motor vehicle behaviour which is produced as a result of adjusting a manipulated variable being continually detected using a current motor vehicle speed v_IST, which is used as a control variable, the control variable v_IST being compared with a desired motor vehicle speed v_SOLL, which is used as a reference variable; an electronic control unit which directly or indirectly detects variables related to operating conditions of the motor vehicle and adjusts additional braking moments when driving on steeply inclined roads; a downhill momentum compensation circuit which superimposes a corrective signal a_N, which is determined according to at least one of (i) a current incline and (ii) an actual incline a_NEIGUNG of a slope which is driven on, onto the output signal of the brake regulator a_R; and an HDC adjuster which adapts the reference variable v_SOLL depending on a target variable v_ZIEL and the control variable v_IST, where the reference variable v_SOLL is selected in accordance with one of the following ranges: a first range v_IST-Δv>v_ZIEL, the following applies: v_SOLL:=v_IST-Δv, where Δv is an offset and whereby the reference variable v_SOLL is brought closer to the target variable v_ZIEL in a uniform manner depending on the control variable v_IST; a second range v_IST-Δv<=v_ZIEL, the following applies: v_SOLL:=v_ZIEL, whereby, as soon as the control variable v_IST, minus the offset Δv, reaches the target variable v_ZIEL or falls below the target variable v_ZIEL, the target variable v_ZIEL is immediately accepted as a reference variable v_SOLL; and a third range v_IST<=v_ZIEL-Δv, the following applies: v_SOLL:=v_ZIEL or v_SOLL:=v_IST+Δv, whereby either the target variable v_ZIEL is immediately accepted as a reference variable v_SOLL or the reference variable v_SOLL is brought closer to the target variable v_ZIEL in a uniform manner depending on the control variable v_IST, with the offset Δv being dynamically varied depending on the control variable v_IST such that it becomes greater when the control variable v_IST increases.