US 5,634,446 A · Cruise control based retarder control

Abstract

A cruise control based retarder control. If the vehicle speed exceeds the cruise control set speed, the cruise control system continuously checks the vehicle speed and acceleration order to determine the optimum auxiliary brake level based upon the amount of overspeed and acceleration. The cruise control system allows the vehicle driver to select which auxiliary brakes will be applied to slow down the vehicle to the desired speed by means of the normal cabin brake switches, limited by the determined optimum brake level. The driver can therefore control which auxiliary brakes are applied, however the application of these brakes is controlled by the cruise control system without the need to exit cruise control mode. Operation of the auxiliary brakes by the cruise control system will normally reset in increased fuel economy over prior art systems which require exiting of the cruise control system, manual activation of the auxiliary brakes and resumption of the cruise control system.

Claims14

Dependent claims

A method for controlling application of a vehicle's auxiliary brakes without exiting cruise control, comprising the steps of:

(a) providing a plurality of auxiliary brakes operable to resist a forward motion of the vehicle when activated;
(b) receiving a first commanded brake state from a driver of the vehicle, wherein the first commanded brake state selects which of the plurality of auxiliary brakes the driver wishes to be activated;
(c) determining a second commanded brake state by comparing a current vehicle acceleration with at least one predetermined acceleration limit;
(d) selecting one of the first or second commanded brake states which commands activation of a lesser number of the plurality of auxiliary brakes than another one of the first or second commanded brake states;
and
(e) activating the auxiliary brakes selected in step (d).

3 more elements

A method for controlling application of a vehicle's auxiliary brakes without exiting cruise control, comprising the steps of:

(a) providing a plurality of auxiliary brakes operable to resist a forward motion of the vehicle when activated;
(b) receiving a first commanded brake state from a driver of the vehicle, wherein the first commanded brake state selects which of the plurality of auxiliary brakes the driver wishes to be activated;
(c) determining a current second commanded brake state by comparing a current vehicle acceleration with at least one predetermined acceleration limit;
(d) redetermining the second commanded brake state by comparing a current vehicle speed with at least one predetermined speed limit if the current second commanded brake state determined in step (c) is equal to a previous second commanded brake state;
(e) selecting one of the first commanded brake state or the second commanded current brake states which commands activation of a lesser number of the plurality of auxiliary brakes than another one of the first or second commanded brake states;
and
(f) activating the auxiliary brakes selected in step (e).

4 more elements

Dependencies are inferred from the claim text.

Cruise control based retarder control

Life of this patent

Cruise control based retarder control

Life of this patent

Abstract

Claims14