CONTROL DEVICE OF RESTARTING AFTER STOP TO THE IDLE

CONTROL SYSTEM RESTART AFTER STOPPING IDLING

Field 1¹ invention

The present invention relates to a control system restart after idle stop mounted mainly on a vehicle, for controlling the restarting an internal combustion engine (engine) after an idling stop using a synchronous motor-generator without sensor operating as a generator after restarting the engine and that also functions as a starter motor when the engine is to be restarted after the idle stop. The synchronous motor-generator without sensor does not use a position sensor for detecting a position of a rotor.

Description of the related art

In recent years, in the vehicles using the internal combustion engine as a power source, an idling stop is increasingly introduced to improve the fuel efficiency and the reduction of exhaust emissions. For introducing more the idling stop, idle stop various systems have been proposed.

As a method of calculating the position of the rotor based on an estimate for controlling an armature winding without sensor for detecting the position of the rotor in a three-phase motor on a vehicle, a technique for controlling a sensorless brushless motor for controlling a compressor of an air conditioner, which is used for an automotive electrical controller, has been reported (see e.g. the document JP 07-115791 A).

However, the related art has a problem. Operated said self-controlled as in the conventional example described above, an induced voltage generated on the side of the armature is detected. From the induced voltage detected, the number of rotations and an angular position of the rotor are calculated based on an estimate. Based on the number of revolutions and the angular position of the rotor thus calculated, the supply of the armature is controlled at the optimum timing.

With a small number of rotations which does not permit controlling the supply by the self-controlled operation described above, an engine is started by a control prospective. Prospective In the control, a flow rotating magnetic force is applied to the armature, hoping that the rotor follows the rotating magnetic flux. This method is called external control operation.

Operation self-controlled and the operation external control are known. The engine that can be started by the operation external control is used in a limited manner that when a load torque at the starting time is relatively low. Therefore, a starter motor for an internal combustion engine, with a load torque extremely large, cannot be started by the operation external control.

The present invention was performed to solve the problem described above, and provide a system restart control after idling stop capable of widen the detection range of an induced signal, which is induced in an armature winding of the synchronous motor/generator and delivered by sensorless thereof, by a circuit for detecting induced signal in controlling the power supply to a field winding of a rotor of the synchronous motor-generator sensorless by a control circuit of induction for amplifying the induced signal.

The other object is to provide to provide the control system restart after idle stop capable of broadening the range of the number of rotations and an angular position of the rotor, may be calculated by a control circuit restart based on the induced signal, to a rotation number of border and a corresponding angular position immediately before a complete stop by widening the detection range of the induced signal, which, in turn, can extend the operating range for operation in a self-controlled to a time just before the complete stop.

A control system restart after idle stop according to the present invention comprises: a synchronous motor-generator without sensor comprising an armature winding and a rotor comprising a field winding, the motor-generator sensorless synchronous functioning as a generator after the start of an engine and operating as a starter motor when the engine is restarted after an idling stop; a signal detection circuit to detect a signal induced armature delivered by the armature winding; a drive control circuit to control the power supply of the field winding; and a control circuit configured to restart: delivering, the excitation driver, a control signal to control the power supply of the field winding to amplify the signal induced while calculating a number of rotations and an angular position of the rotor based on the induced signal detected by the signal detection circuit armature when an engine stop command is applied and a level of the induced signal detected by the signal detection circuit armature is equal to or below a predetermined value; and outputting the control signal to control the power supply of the armature winding to re-start the engine based on the number of rotations calculated and the angular position of the rotor when a restart command is applied.

According the control system restart after idle stop of the present invention, the supply of the field winding of the rotor of the synchronous motor-generator is controlled by the sensorless drive control circuit for amplifying the induced signal. Therefore, the detection range of the induced signal, which is induced in the armature winding of the synchronous motor-generator and sensorless delivered therefrom can be widened.

Furthermore, the range extended detection of the induced signal makes it possible to extend the range of the number of rotations and the angular position of the rotor, which can be calculated by the restart control circuit based on the induced signal, to the number of rotations boundary and the corresponding angular position immediately before the complete stop, which, in turn, makes it possible to extend the operating range for operating self-controlled to a time just before the complete stop.

On the drawings:

figure 1 is a scheme illustrating a configuration of a system restart control after idling stop according to a first embodiment of the present invention;

figure 2 is a timing diagram illustrating an operation of a synchronous motor-generator sensorless control system restart after idle stop according to the first embodiment of the present invention from an idle stop to the restart;

figure 3 is a timing diagram illustrating the induced signals delivered to the respective phases of an armature winding of the synchronous motor-generator switch zone A;

figure 4 is a timing diagram illustrating the induced signals supplied to the respective phases of the armature winding of the synchronous motor-generator switch B area;

figure 5 is a graph illustrating a relationship between the induced signal and the number of rotations of a rotor when the sensorless synchronous motor-generator is running at low speed;

operation of a control circuit system reboot restart control after idling stop according to the first embodiment of the present invention.

Thereafter, a preferred embodiment of a control system restart after idle stop of the present invention is described with reference to the accompanying drawings.

The first embodiment

A control system restart after idle stop according to a first embodiment of the present invention is described with reference to Figures 1 to 7. Figure 1 is a scheme illustrating a configuration of the control system restart after idle stop according to the first embodiment of the present invention.

As shown in Figure 1, the control system restart after idle stop comprises: an armature winding 1 ; a rotor 2 comprising a winding inductor 2a; a drive control circuit 3 ; 4 a bridge rectifier circuit; a pilot control circuit 5 ; a signal detection circuit 6 armature; a control circuit 7 restart; a stabilized power supply circuit 8 for the control circuit 7 restart; a battery on-vehicle 9 ; a serial communication interface circuit 10 ; an electronic control unit (ECU) 11 for controlling the motor ("force"); idle control circuit 12 ; brake switch 13 ; a vehicle speed sensor 14 ; and a shift position sensor 15. The armature winding 1 and the rotor 2 form a synchronous motor-generator without sensor 100. The drive control circuit 3 is operable to supply the winding inductor 2a and controls power to the field winding 2a for amplifying a signal armature. The bridge rectifier circuit 4 has both a supply function of the armature winding 1 and a function of extraction of the electric power generated by the synchronous motor-generator without sensor 100. The pilot control circuit 5 converts a voltage of a control signal and the like. The signal detector circuit detects an induced signal armature 6 delivered by the armature winding 1. Restart The control circuit 7 such as a microcomputer includes a memory. The serial communication interface circuit 10 serves for communication with an electronic device described below. The circuit idle control 12 is an ECU or the like independent of the ECU 11 for controlling the motor. The brake switch 13 detects a brake application. The vehicle speed sensor 14 detects a speed of a vehicle. The shift position sensor 15 detects a position of a shift lever.

The electric power generated by the synchronous motor-generator without sensor 100 passes through the bridge rectifier circuit 4 and a load circuit (not shown) for charging the battery on-vehicle 9. Restart The control circuit 7, the ECU 11 for controlling the motor, and the idle control circuit 12 are connected via a communication line vehicle network.

Dedicated On the conventional engine restart (not shown) and of a conventional generator (not shown) which are mounted on the vehicle, the synchronous motor-generator without sensor 100 according to the first embodiment replaces the conventional generator. The conventional engine dedicated to the restart is used for the normal start of the engine using the "ON" position (contact) of an ignition key as a trigger. The conventional generator charges the battery on-vehicle 9.

The rotor of the synchronous motor-generator 2 without sensor 100 rotates at a speed (for example, about a speed twice = about 1400 rpm) equal to a multiple corresponding to an acceleration speed of a belt (not shown) which links an internal combustion engine (hereinafter simply called engine) rotating to the number of revolutions during idling (for example, about 700 rpm) and the synchronous motor-generator without sensor 100.

Figure 2 is a timing diagram illustrating an operation of the synchronous motor-generator sensorless control system restart after idle stop according to the first embodiment of the present invention from an idle stop restart. On Figure 2, an axis of abscissa represents an elapsed time, while a Y-axis represents the number of rotations of the rotor of the synchronous motor-generator 2 without sensor 100.

T0 A time corresponds to a time at which an engine stop procedure is performed by the ECU 11 for controlling the engine during idling. T0 Before the time, the engine is in an idling state and is controlled to the number of revolutions during idling. 2 The rotor of the synchronous motor-generator 100 rotates sensorless NA to the number of rotations corresponding to the number of rotations of the engine during idling.

Tl A time corresponds to a time in the middle of an engine stopping process. T0 In the time at the time Tl, the motor rotates at the number of rotations of the motor, that allows the engine to be restarted by the recovery of the fuel control and ignition control with a force of self-rotation, i.e. that provides for self-recovery engine. The number of rotations of the rotor of the synchronous motor-generator 2 without sensor 100, which corresponds to a limited number of rotations of the motor at the time Tl, for self-recovery, is determined as a first threshold value NI. T0 An area between the time and the time Tl is determined as region A.

After this, the number of rotations of the motor further reduces. A other time T2 corresponds to a time in the middle of the engine stopping process. At the time T2, the number of rotations of the engine reaches a limited number of rotations of the motor, which corresponds to a boundary for the detection of the induced signal which is induced in the armature winding 1 and delivered by the latter. The number of rotations of the rotor of the synchronous motor-generator 2 without sensor 100, which corresponds to the number of rotations of the motor to limit the time T2, is determined as the second threshold value N2. Here, the limit number of rotations of the motor corresponds to the boundary allowing the detection of the induced signal. An area between the time Tl and the time T2 is determined as an area B.

A time T3 corresponds to a time at which the motor and the synchronous motor-generator 100 sensorless stop completely. After the time T3, the engine restarts from a state of complete stop. A time period between the time T2 and the time T3 is extremely short. Therefore, as in the case of time after the time T3, the engine restarts from the state of complete stoppage during the time period between time T2 and the time T3. An area after the time T2 is determined as an area C.

Figure 3 is a timing diagram illustrating the induced signals supplied to the respective phases of the armature winding of the synchronous motor-generator without sensor in the region A. On Figure 3, an axis of abscissa represents the time, while a axis of ordinate represents a level of each of the induced signals. Note that the induced signal is an induced voltage or an induced current. Furthermore, in Figure 3, an output cycle of the induced signal for one phase is Tsl , while a half-cycle is Ts2.

Figure 4 is a timing diagram illustrating the induced signals supplied to the respective phases of the armature winding of the synchronous motor-generator switch zone B. On Figure 4, an axis of abscissa represents the time, while a axis of ordinate represents a level of each of the induced signals. Compared to induced signals in the area A which is shown in Figure 3, the area B corresponds to the process in which the motor and the rotor of the synchronous motor-generator 2 without sensor 100 arrive at a complete stop. Therefore, the number of rotations of the rotor 2 is low, and therefore the level of each of the induced signals is less than that in the region A. One cycle of output of the induced signal for one phase is Ts3, and gu ' a half-cycle is Ts4. Due to the reduction of the number of rotations, and relationships Tsl < Ts3 Ts2 < Ts4 are established.

Figure 5 is a graph illustrating a relationship between the induced signal and the number of rotations of the rotor lorsgue the sensorless synchronous motor-generator is running at low speed. On Figure 5, an axis of abscissa represents the number of rotations of the rotor of the synchronous motor-generator 2 without sensor 100, and gu ' an axis of ordinate represents a peak level of the induced signal. Solid line S0 A provides the signal induced without excitation current, a solid line indicates the signal induced SI when an exciting current is low, and a solid line indicates the induced signal S2 when the excitation current is large. From of the induced signal, the number of rotations of the rotor of the synchronous motor-generator 2 without sensor 100 can be calculated. Each points NL0, NL1 and NL2 on the X-axis provides the number of rotations of the rotor 2 at a level detection limit of the induced signal (on the ordinate axis), which is the border for the detection of the induced signal from the signal detection circuit armature 6. The point NL0 provides the number of rotations of the rotor 2 without excitation current, NL1 the point indicates the number of rotations when the excitation current is low, and the point NL2 indicates the number of rotations when the excitation current is large. As shown in Figure 5, the induced signal is amplified by increasing the excitation current. In conséguence , the signal induced can be detected even when the rotor 2 rotates at a lower number of rotations. NL2 The number of rotations immediately prior to the complete stop is identical to the second threshold value N2 shown in Figure 2.

Furthermore, an operation of the control system restart after idle stop according to the first embodiment is described with reference to the

present invention. Figure 7 is a flow chart illustrating a operation of the control circuit system reboot restart control after idling stop according to the first embodiment of the present invention.

At step 101 shown in Figure 6, the idle control circuit 12 determines whether, or not, conditions for judging an engine stop are satisfied for a idling. It is determined that the conditions for judging the engine is stopped are satisfied when the brake switch 13 is closed ("ON"), the vehicle speed detected by the vehicle speed sensor 14 is zero, and the position of the gearshift lever of an automatic transmission (AT), which is detected by the shift position sensor 15, is located in a range N. On the other hand, even when the one of the three conditions is not met, it is determined that conditions for judging the engine is stopped are not satisfied.

The vehicle is stopped by a brake operation carried out when the vehicle is controlled to move. For 1' brake actuator, the brake switch 13 is activated. The condition for judging can also be the positioning of the shift lever in a range P, which position causes the continued arresting of the vehicle. Furthermore, the type of transmission is not limited the AT transmission, and a manual transmission (MT) can be used instead.

Furthermore, whether the conditions for judging the engine is stopped are satisfied (yes), the idle control circuit 12 outputs an engine stop command in step 102. The control circuit 12 delivers idle engine stop control to the ECU 11 for controlling the motor via the network communication line and also vehicle restart to the control circuit 7 via the network communication line of the vehicle and serial communication interface circuit 10.

Based on engine stop control, the ECU 11 for controlling the motor stops the ignition control and the fuel control of the engine. The stop operation of the ignition control of the fuel control and corresponds to the engine stop procedure and is performed at the time T0 shown in Figure 2. The number of rotations of the rotor of the synchronous motor-generator 2 without sensor 100 follows a rotational behavior of the engine so as to decrease the number of revolutions during idling until the engine is completely stopped, i.e., the number of rotations to the number of rotations NA NI, then the number of rotations N2, and finally to zero as shown in Figure 2.

Furthermore, in step 103, the control circuit 12 determines whether idling, whether or not, a condition for judging the restart is satisfied. Even when any one of the conditions for judging the restart is not satisfied, it is determined that the condition for judging the restart is satisfied. For example, if the position of the shift lever from the transmission AT, which is detected by the shift position sensor 15, is passed in a D range, it is determined that the condition for judging the restart is satisfied. On the other hand, when the conditions for judging the engine is stopped are satisfied, it is determined that the condition for judging the restart is not satisfied.

Furthermore, if the condition for judging the restart is satisfied (yes), the idle control circuit 12 outputs a restart command in step 104. The idle control circuit 12 issues the command to restart the ECU 11 for controlling the motor via the network communication line and at restart control circuit 7 via the network communication line of the vehicle and serial communication interface circuit 10.

The ECU 11 for controlling the motor starts the ignition control and the fuel control for the engine based on the restart control.

Although carrying out the process of determining whether the conditions for judging the engine stop or the condition for judging the restart are satisfied or not (steps 101 to 104) in the idle control circuit 12 has been described, the process can also be performed in the ECU 11 for control of the engine to which a source of information necessary is connected.

At step 201 shown in Figure 7, the control circuit determines whether restart 7, whether or not, engine stop control has been applied by the idle control circuit 12.

Furthermore, if engine stop control has been applied (yes), the restart control circuit 7 determines whether, or not, the peak level of the induced signal detected and applied by the signal detection circuit armature 6 is equal to or less than a predetermined value in step 202. The predetermined value corresponds to the peak level of the induced signal, which is detected when the number of rotations of the rotor 2 shown in Figure 2 is equal to the first threshold value NI.

Thereafter, in step 203, if the level of the induced signal is equal to or less than the predetermined value (yes), the restart control circuit 7 controls the supply of the field winding 2a of the rotor 2. In order to prolong the induced signal, the restart control circuit 7 outputs a control signal to control the power supply of the field winding 2a. The control signal passes through the pilot control circuit 5 to reach the drive control circuit 3. The drive control circuit 3 controls the supply of the field winding 2a based on the control signal so that the amplified induced signal S2 shown in Figure 5 is induced and delivered.

Furthermore, in step 204, the restart control circuit 7 calculates the number of revolutions and angular position of the rotor 2 from the induced signal detected and applied by the signal detection circuit armature 6 and then stores the number of rotations and the angular position calculated in the memory. The amount of rotation and the angular position calculated for each processing cycle are stored one by one in the memory in time series.

Before zone A shown in Figure 2, the rotor 2 rotates to the number of rotations NA in accordance with the number of rotations of the engine during idling.

In zone A shown in Figure 2, the number of rotations of the rotor 2 gradually decreases. A state of the induced signal supplied to the armature winding 1 at that time is shown in Figure 3. The angular position of the rotor 2 may be calculated from the variation of the induced signal guantité delivered in each of the phases, while the cycle of rotation (= number of rotations) of the rotor 2 can be calculated from the output cycle or Tsl Ts2 of the half-cycle of the induced signal.

When the induced signal is a voltage induced, the number of rotations of the rotor 2 can be calculated from a time (the output cycle ends Tsl or of the half-cycle Ts2) to which the voltage passes through 0 V in a U-phase, as shown in Figure 3. At the point voltage 0 V (at the end of the output cycle Tsl or of the half-cycle Ts2) by which the induced voltage passes, an electrical angle between the armature and the rotor 2 becomes equal to 180 degrees or 360 degrees. Therefore, from the output cycle or Tsl Ts2 of the half-cycle, the angular position of the rotor 2 can

number of rotations of the rotor 2 is decelerated to a complete stop. A state of the induced signal supplied to the armature winding 1 at that time is shown in Figure 4. In zone B, well as the number of rotations of the rotor 2 decreases to gradually decrease the level of the induced signal, the induced signal is supplied to the armature winding 1 until the very end. Therefore, continuously detecting the induced signal allows calculate the angular position and the number of rotations of the rotor 2 from the amount of variation of the induced signal and the output cycle Ts3 Ts4 or of the half-cycle in the manner described above until the number of rotations decreases at limited number of rotations (second threshold value N2 shown in Figure 2) corresponding to the boundary for the detection of the induced signal.

Furthermore, in step 205,

restart 7 determines whether,

current rotations of the rotor 2,

204, is equal to or less than

threshold N2.

the control circuit whether or not, a number of which is calculated in step than the second value of

Furthermore, in step 206, if the number of revolutions is equal to or smaller than the second threshold value N2 (yes), the restart control circuit 7 calculates the angular position of the rotor 2 when the rotor 2

when the rotor 2 stops in the memory. As described above for the step 204, the angular positions and the numbers of rotations calculated of the rotor 2 are stored in the memory until the number of rotations decreases at limited number of rotations (second threshold value N2) corresponding to the boundary for the detection of the induced signal from the signal detection circuit armature 6. Therefore, from the relationship between the angular position and the number of rotations of the rotor 2 to the elapsed time (T0-T1-T2), the angular position of the rotor 2 when the rotor 2 stops, at the time T3, to which the number of rotations is zero, can be calculated.

Specifically, as shown in Figure 2, at the time T3, to which the number of rotations is zero, can be calculated from the relationship between the variation of the number of rotations of the rotor 2 and the elapsed time (T0-T1-T2). Furthermore, the angular position of the rotor 2 when the rotor 2 stops at the time T3 may be calculated from the relationship between the elapsed time (Τ0-Τ1-Τ2) and the variation of the angular position of the rotor 2.

Furthermore, in step 207, the control circuit determines whether restart 7, whether or not, the restart instruction has been applied by the idle control circuit 12. If the restart instruction has not been applied (non-), the restart control circuit 7 waits (delays determining the application the restart control) for a predetermined time after the processing in step 206 has been performed once and then determines again if, whether or not, the restart control has been applied.

Furthermore, if the restart instruction has been applied (yes), the restart control circuit 7 outputs a control signal to control the power supply of the armature winding 1 to restart the motor in step 208. To this step, the restart control circuit 7 is set to zero memory storing the numbers of rotations and angular positions.

When the elapsed time is in the area A, specifically, the number of rotations of the rotor 2, which is calculated in step 204, is greater than the first threshold value NI, the number of rotations of the motor is the one which allows the self-recovery engine. Therefore, the engine can be re-started by repeating the control (ignition control and fuel control for the motor) performed by the ECU 11 for controlling the motor. Therefore, the restart control circuit 7 does not carry out the engine restart in the area A.

In zone B, specifically, when the number of rotations of the rotor 2, which is calculated in step 204, is equal to or less than the first threshold value NI and greater than the second threshold value N2, the restart control circuit 7 executes the restart of the engine based on the rotational speed, and the current angular position of the rotor 2, which are calculated in step 204. For re-start the engine, the restart control circuit 7 supplies the control signal to control the power supply of the armature winding of the synchronous motor-generator 1 without sensor 100. The control signal to restart, which is provided by the control circuit restart 7, passes through the pilot control circuit 5 and the bridge rectifier circuit 4 to flow through the armature winding 1 as armature current, thereby restarting the engine.

C In the region, specifically, when the number of rotations of the rotor 2, which is calculated in step 204, is equal to or less than the second threshold value N2 or zero (full stop), the restart control circuit 7 executes the restart of the engine based on the angular position of the rotor 2 when the rotor 2 stops, which is calculated in step 206. For re-start the engine, the restart control circuit 7 supplies the control signal to control the power supply of the armature winding of the synchronous motor-generator 1 without sensor 100.

The ECU 11 for engine control may detect a failure at restart performed by the restart control circuit 7 by using the motor generator 100 sensorless synchronous from the number of rotations of the motor after the application of the restart control or the like. In the case where the restart using the synchronous motor-generator 100 without sensor has failed, the ECU 11 for controlling the motor performs the restart using a motor provided separately dedicated to the restart as backup to the restart control circuit 7.

As described above, according to the first embodiment of the present invention, the supply for the winding inductor 2a of the rotor 2 of the synchronous motor-generator without sensor 100 is controlled by the drive control circuit 3 for amplifying the induced signal. Therefore, the detection range of the induced signal which is induced in the armature winding of the synchronous motor-generator 1 without sensor 100 and delivered by the latter by the signal detection circuit armature 6 can be widened.

Furthermore, the enlargement of the sensing area of the induced signal allows the widening of the range of the number of rotations and the angular position of the rotor 2, which can be calculated by the restart control circuit 7 based on the induced signal, to the second threshold value N2 and to the corresponding angular position immediately before the complete stop, which, in turn, makes it possible to extend the operating range for operating self-controlled to a time just before the complete stop.

Furthermore, the widening of the range of the number of rotations and the angular position of the rotor 2 computable to a time just before the stopping full the correct calculations of the angular position of the rotor 2 of the motor-synchronous generator without sensor 100 when the rotor 2 stops. Based on the angular position of the rotor 2 when the rotor 2 stops, the engine can be re-started even after the complete stop.