A vehicle powered by an electric motor which may be operated as a generator to effect regenerative braking of certain vehicle wheels in combination with individual friction brakes associated with other wheels. A commanded vehicle deceleration is apportioned among the wheels by determining the maximum regenerative braking deceleration achievable by drive wheels, and braking the vehicle occurs solely by regenerative braking so long as the commanded deceleration is less than the determined maximum deceleration. When a commanded deceleration exceeds the determined maximum, the regenerative braking is supplemented with friction braking of the other wheels while the maximum regenerative braking is maintained. The maximum regenerative braking of the certain wheels may be supplemented with additional friction braking of those same certain wheels, but this occurs only if the combined deceleration of the regenerative braking of the certain wheels and the friction braking of the other wheels is inadequate to achieve the commanded deceleration.

Maximized regenerative braking vehicle braking controller

A brake unit for automotive vehicles with electric drive is configured in the shape of a multiple-circuit compound system consisting of hydraulic friction brakes of brake circuits (I, I', I", III, III', III") and of an electroregenerative brake system (circuit II, II', II"). In a vehicle with a driven and a non-driven axle, three brake circuits exist, one brake circuit of which (I, I', I") is comprised of a pedal-actuated hydraulic brake pressure master unit (2) and of friction brakes (3, 4) acting upon the non-driven wheels. The second brake circuit (II, II', II") which represents an electroregenerative brake system is directly or indirectly coupled to the brake pedal and acts upon the driven wheels. The third brake circuit (III, III', III") which is comprised of friction brakes (10, 11) also acts upon the driven wheels. The actuation of the wheel brakes (10, 11) is connected to the second and third brake circuits. The distribution of the brake power to the front axle (VA) and to the rear axle (HA) is controlled with the aid of an electronic controller (7, 7',7").

Brake system for automotive vehicles with electric drive

In a brake system in an electric vehicle comprising a follower wheel capable of being hydraulically braked by the operation of a brake operating element, and a driving wheel connected to and driven by a motor using a battery as an energy source and capable of being hydraulically braked and regeneratively braked by the operation of the brake operating element, the regenerative braking force for the driving wheel exceeds a theoretic distribution characteristic of the braking forces for the follower and driving wheels at least during an initial braking. Thus, it is possible to sufficiently perform the recovery of the kinetic energy of the vehicle by the regenerative braking to increase the possible travel distance of the vehicle. In addition, at least during an initial braking, the hydraulic braking of the driving wheel and the hydraulic braking of the follower wheel are inhibited, and substantially only the regenerative braking of the driving wheel is performed. Thus, it is possible to recover the kinetic energy of the vehicle without consumption thereof by the hydraulic braking to increase the possible travel distance of the vehicle.

Brake system in electric vehicle

A circuit and system particularly for controlling the current flow to a load, such as an electric motor which propels a vehicle along the earth''s surface. One specific chopper circuit includes two main current carrying SCRs which are each serially connected with an inductance. Two pairs of commutating SCRs are each connected between the anode and cathode of the main SCRs, respectively, via a single capacitance. The main SCRs are alternately rendered conductive and thereafter non-conductive by connecting the capacitor to the conducting main SCR via a pair of commutating SCRs to back-bias the conducting SCR and produce an output signal in which all odd mode harmonics are eliminated, while the even mode harmonics are significantly reduced, thus considerably improving the form factor of the load current. The circuit finds particular utility in a ''''3 in 1 system'''' in which a single chopper circuit is used to control the flow of electrical energy from the batteries to the motor for propelling the vehicle, the flow of electrical energy to the batteries from the motor during regenerative braking, and the flow of electrical energy to the batteries from an exterior source during recharging.

Commutating circuit for electrical vehicle

Eine Bremsanlage fur Kraftfahrzeuge mit elektrischem Antrieb besteht im wesentlichen aus einer angetriebenen Vorder- (VA) und einer nicht angetriebenen Hinterachse (HA), die in Form eines dreikreisigen (I, II, III), aus hydraulischen Reibungsbremsen (3, 4, 10, 11) und aus einem elektro-regenerativen (II) Bremssystem bestehenden Verbundsystems ausgebildet ist, wobei das elektroregenerative Bremssystem einen der elektrischen Antriebsmotore des Kraftfahrzeuges zur Abbremsung und zur Energieruckgewinnung nutzt. Die Betatigung an den zweiten und an den dritten Bremskreis angeschlossenen Reibungsbremsen und die Bremskraftverteilung auf die Vorder- und Hinterachse sind mit Hilfe eines elektronischen Reglers steuererbar, der Information uber Z.B. die Bremspedalstellung erhalt und diese Information zur Steuerung der auf die angetriebenen Rader wirkenden Bremsen auswertet.

Bremsanlage für kraftfahrzeuge mit elektrischem antrieb

A braking and driving system for electrically operated vehicles including an electric motor for driving the vehicle which may be operated as a generator to provide additional braking and recovery of braking energy by charging the battery. Hydraulic braking on the drive axle is delayed until the maximum level of electromotive braking is reached. This allows the design distribution of braking between the front and rear axles to be maintained while insuring a maximum recovery of braking energy through charging of the battery.

Heinrich Oberthuer

Papers

Brake system for electrically operated vehicles

Bremssystem fuer Elektrofahrzeuge