DE102007047589A1 - Dynamic stop with parallel hybrid - Google Patents

Abstract

The invention relates to a method for deactivating the internal combustion engine of a parallel hybrid drive, which comprises the internal combustion engine, an electric motor and a controllable separating clutch, which connects the internal combustion engine with the electric motor. The method comprises the steps of: detecting a decoupling signal and, upon detection of the decoupling signal, changing the speed control by blocking control of the engine speed depending on a driver's request and driving the internal combustion engine to a speed corresponding to a torque transfer from the internal combustion engine to the clutch of the engine Essentially equal to zero. After the control of the engine speed has been blocked depending on a driver's request, the separating clutch is opened. Furthermore, the invention relates to an associated control.

Description

State of the art

The The invention is based on a control method for a parallel hybrid drive. A parallel hybrid drive has the same structure as a conventional one Work strand of an internal combustion engine drive, however, are additionally between transmission and combustion engine an electric motor and a Disconnect the engine of the drive train can separate. The combustion engine and the electric motor are thus connected in series, with a separating clutch controls whether a Torque generated by the internal combustion engine over the Electric motor is led to the output.

Control method the moment coordination, d. H. the division of torque generation, provide generate with strong rule changes, in particular when completely switching off the internal combustion engine, an unpleasant Driving behavior, which manifests itself as jerking.

It is therefore an object of the invention, a motor control for a Provide parallel hybrid, the switching off an internal combustion engine a parallel hybrid drive designed more pleasant.

Disclosure of the invention

The Invention allows the shutdown of an internal combustion engine of a parallel hybrid drive, without to affect the driving behavior unpleasant. Furthermore, an existing Moment coordination structure can be used, for example is provided in the form of a combined engine control. This allows stopping the internal combustion engine while driving, d. H. the transition to the full Electric drive without this for the driver noticeable is.

The The concept underlying the invention is the separating clutch initially load-free between engine and electric motor, to then open the separating clutch. Because the separating clutch is load-free, d. H. the entire drive torque from the downstream Electric motor is generated, has the drive behavior of the internal combustion engine no influence on the driving behavior, so that of the internal combustion engine generated drive torque during the shutdown does not affect the driving behavior. To do this the torque limits of the internal combustion engine or the target generation torque of the internal combustion engine so specified that the side of the separating clutch, which faces the engine synchronously with the side is, which faces the electric motor, so that the separating clutch no moment of the internal combustion engine transmits into the following drive train. For this may be the speed of the internal combustion engine and / or its moment regulated as a controlled variable become. A signal that corresponds to the driver's request, for example a Signal derived from the accelerator pedal becomes the driver request signal Completely pass to the electric motor, wherein the internal combustion engine receives signals, the are designed to provide the disconnect clutch load. Preferably receives the engine control a signal according to which the internal combustion engine no longer available as a drive unit. The control, which carries out the torque coordination thus observes the internal combustion engine no more and no longer use this to create moments, but gives the driver only to the e-machine on. This can be done, for example, that the driver request signal is redirected accordingly and the signal path to the engine is blocked.

After this Thus, the internal combustion engine generates no more torque, the electric motor the whole Drive torque generated and the driver's request not to the internal combustion engine or its control, but forwarded to the electric motor is, the disconnect clutch is opened. Because the separating clutch when opening no moment transmits (finally is it becomes stress-free due to the internal combustion engine control) the drive train by opening the separating clutch is not affected or excited.

After this the clutch is opened has been stopped, the internal combustion engine is stopped. Alternatively, you can the internal combustion engine also during or just before opening the separating clutch are stopped. This depends on the behavior of the internal combustion engine while the stop phase, since it can be designed in such a way that despite Connection with the electric motor of the internal combustion engine drive not significantly affected.

The different steps, ie Step 1: Load-free provision of the clutch by controlling the internal combustion engine, Stage 2: Notify the engine control that the engine is no longer available and that the driver's request is only to pass on to the electric motor, Step 3: Open the disconnect clutch and step 4: stopping the engine, can also be temporally combined with each other. Preferably, steps 2-4 are performed during the same time interval. Preferably, the engine speed is kept constant via idle control to prevent the engine from whining when the disconnect clutch is opened or opened. In addition, for the combustion motor when opening or after opening the clutch a predetermined change in speed can be controlled, for example, reducing the speed in the form of a ramp.

Of the Internal combustion engine can also be turned off while preparing to open the disconnect clutch are taken to a time delay of the Internal combustion engine to take into account between the actual input and the reaction of the internal combustion engine, and on the other to the Period of time to be taken during the shutdown of the Internal combustion engine elapses. The internal combustion engine is going through corresponding signals are turned off to the engine control, for example, reduces the speed, the degree of leadership reduces and / or the firing angle adapted to a lower speed and to a lower torque.

The inventive method thus comprises the control of three different components: the Torque control, which determines the torque of the internal combustion engine and of the electric motor controls, the clutch and the control of the internal combustion engine. First a signal is detected, accordingly the internal combustion engine This is automatically done by another controller or generated by a driver by corresponding actuation of a button can be. First the clutch is driven load-free, so that the torque control, d. H. the moment coordination receives a signal, accordingly a differential torque of Zero is to be set at the separating clutch. Then the torque control switched to 100% electrical operation by the torque control receives a corresponding switching signal. From this switching will be Driver request signals no longer to the engine control, but only passed on to the electric motor control since only the electric motor participates in the torque generation. Then the separating clutch is opened, in which step the disconnect clutch an opening signal receives. The opening signal may be a corresponding signal edge or a signal level.

To the opening or during the opening of the Disconnect the engine is turned off, this is provided by the engine control receives a shutdown signal. The Shutdown signal may be a single, specific signal, or can by appropriate ignition angle, Speed or filling level signals provided be, for example, by a specification degree of filling = zero or one Default speed = zero.

After this the internal combustion engine is switched off, the disconnect clutch remains open and the torque or motor control becomes complete for the electric motor intended. In particular, the driver request signal is completely on forwarded the electric motor and the regulation of the electric motor is set so that the electric motor generates the total setpoint torque.

Brief description of the drawings

embodiments The invention is illustrated in the drawings and in the following Description closer explained.

It demonstrate

1 a schematic diagram of a parallel hybrid drive, and

2 a block diagram of an embodiment of the circuit according to the invention

Embodiments of the invention

In the 1 is a schematic diagram of a parallel hybrid drive shown. A parallel hybrid drive includes an internal combustion engine 10 that has a disconnect clutch 20 with an electric motor 30 connected is. The electric motor is followed by a gearbox 40 , which with the downforce 50 , that is, connected to the wheels of a vehicle. The of the internal combustion engine 10 generated torque component, if provided, therefore passes through the disconnect clutch 20 , the electric motor 30 , The gear 40 , and so gets on the wheels 50 transfer. That of the electric motor 30 Torque generated passes through the gear to get on the wheels 50 to be transferred. The electric motor 30 is thus located between the output 50 and the internal combustion engine 10 , In contrast to the internal combustion engine 10 can the electric machine 30 be switched by switching off the excitation in a passive state by the electric motor receives neither a torque nor one gives off and only the transmission of mechanical power between disconnect clutch 20 (or internal combustion engine 10 ) and the downforce 50 serves.

The 2 shows a circuit structure according to the invention with a motor controller 100 , a torque distribution or moment coordination 102 as well as a separation control 104 includes. The engine control receives an input signal from a driver request input 106 and has two outputs, a first engine output connected to the engine or its control 110 connected, as well as an e-machine output through which an e-machine 130 can be controlled. The engine output and the e-machine output are with the torque distribution 102 connected. The moment distribution 102 also receives a driver request signal from the drive request input 106 , The driver's request can be controlled by another controller or the accelerator pedal.

The torque control 102 can send signals to the engine control 100 and the e-machine control 130 in the form of logical levels. Alternatively, the torque control 102 include a power amplifier, with the internal combustion engine and the electric motor can be controlled directly. In the same way, the separation control 104 logical signals or high power drive signals to the transmission 140 and separating clutch 120 submit. Both the connection between the separation control 104 and the transmission 140 or the separating clutch 120 as well as the connections between the torque control 102 and the internal combustion engine 110 and the electric machine 130 can be provided by means of output terminals. Furthermore, level converters and / or output stages can be used to supply the connected devices with suitable electrical power.

After the separating clutch 120 was opened, the transmission becomes 140 from the separation controller 104 controlled according to the driver's request and the operating parameters of the electric machine. The control of the transmission 140 thus takes into account after the opening of the separating clutch 120 excluding the driver's request and the operating parameters or properties of the electric motor and no operating parameters of the internal combustion engine.

The Motor control or the torque distribution and the separation control can be provided in individual modules that interface with each other are connected. The modules themselves can by means of hardware, software or a combination thereof. In particular, the respective functions by means of a microprocessor or a CPU be implemented, the software and data processed, the Software preferably stored in a non-volatile memory is and the data is input or output data associated with the respective Signals are linked.

Preferably, the separation control, the torque control are provided as software modules that run on the same microprocessor. For controlling the gearbox 140 , the disconnect clutch 120 , the e-machine 130 and the internal combustion engine 110 Interfaces, in particular power interfaces, can be provided. The driver command signal is preferably time-discrete sampled and converted into discrete-value signals to allow processing by a microprocessor.

Claims (10)

Method for deactivating the internal combustion engine ( 10 ) of a parallel hybrid drive, the internal combustion engine ( 10 ), an electric motor ( 30 ), and a controllable separating clutch ( 20 ), which is the internal combustion engine ( 10 ) with the electric motor ( 30 ), comprising the steps of: detecting a decoupling signal; and, upon detecting the decoupling signal: changing the torque control by blocking control of the engine speed depending on a driver's request and driving the internal combustion engine to a speed that is at a torque transfer from the engine to the clutch ( 20 ) of substantially zero; and, after the control of the engine torque has been blocked depending on a driver request, opening the disconnect clutch. Method according to claim 1, wherein the internal combustion engine ( 10 ) after, during, or shortly before opening the separating clutch ( 20 ) is turned off. Method according to claim 1 or 2, wherein the separating coupling ( 20 ) is opened after the internal combustion engine ( 10 ) is driven in such a way that substantially all of the torque applied to the electric motor ( 30 ) following output ( 50 ) is generated by the electric motor ( 30 ) and essentially no torque is applied to the output ( 50 ), from the internal combustion engine ( 10 ) is produced. Method according to one of the preceding claims, wherein the blocking, the driving, the opening and the stopping of the internal combustion engine ( 10 ) is carried out substantially simultaneously. Method according to claim 1, wherein the internal combustion engine ( 10 ) after, during, or shortly before opening the separating clutch ( 20 ) is controlled to a constant speed. Method according to one of the preceding claims, wherein the separating coupling ( 20 ) is opened when the internal combustion engine ( 10 ) was controlled to a speed which is at a torque transfer from the internal combustion engine ( 10 ) on the separating clutch ( 20 ) of substantially zero. Method according to one of the preceding claims, wherein, when the torque transfer from the internal combustion engine ( 10 ) on the separating clutch ( 20 ) is substantially zero, a torque control ( 100 ) is signaled that the internal combustion engine ( 10 ) is deactivated, and if the torque control has been signaled that the internal combustion engine ( 10 ) is deactivated, the torque control only a driver request signal corresponding to the driver request signal to the electric motor ( 30 ) or to an electric motor control, and the internal combustion engine ( 10 ) or an engine control does not receive a driver request signal. Control ( 100 ) for torque sharing in a parallel hybrid drive comprising an electric motor and an internal combustion engine, having a lock configured to inhibit the delivery of a driver request signal to an engine control from the input of an engine deactivation signal, and set prior to input the engine deactivation signal to enable the delivery of a driver request signal to an engine controller, the controller is further configured to deliver the driver request signal to an electric motor controller and deliver a disconnect clutch opening signal upon occurrence of an engine deactivation signal, regardless of the occurrence of an engine deactivation signal. Control according to claim 8, having an input for receiving the driver request signal, an output for delivering an electric motor drive signal, an output for outputting an engine drive signal and an output for outputting a disconnect clutch drive signal. The controller of claim 9, further configured is a torque transfer signal to receive, which indicates the value of the moment that of the internal combustion engine is transferred to the separating clutch or vice versa; set up is to recognize, based on a comparison with a threshold, whether the torque transfer is below the threshold, and is set to capture below the threshold value, a disconnect drive signal leave.