JP2006170116A - Prime mover torque control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a prime mover torque control device securing transmission torque which is transmission input torque smaller than allowable upper limit torque which can be input to a transmission and is sufficient for vehicle acceleration. <P>SOLUTION: This device is provided with an inertia torque operation part 303 operating inertia torque ΔT necessary for raising rotation speed of an engine itself under a transient condition such as time of engine rotation speed rise, and an engine generating torque upper limit value establishing part 305 calculating engine output torque Ti output from an engine output shaft based on engine generating torque Te and inertia torque ΔT and establishing an engine generating torque control value making the transmission input torque smaller than the allowable upper limit torque when the engine output torque Ti input to a transmission exceeds the allowable upper limit torque of the transmission. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a prime mover torque control that performs control so as to reduce a prime mover torque when the input torque to a transmission is excessive.

In this type of technology, when the input torque to the transmission is excessive to protect the transmission, the engine torque is estimated based on the rotational speed such as the speed ratio, and the engine torque is reduced. (For example, refer to Patent Document 1).
JP 2002-138874 A

  However, in the prior art described in Patent Document 1, the engine torque is controlled based on the engine speed in the steady state, and therefore, there is a possibility that excessive torque limitation may be performed in a transient state such as when the engine speed increases. there were. That is, when the engine speed increases, the torque actually input to the transmission is reduced by the inertia of the engine itself. Therefore, if the torque upper limit value is simply set based on the rotational speed such as the speed ratio and the torque is reduced, the driver's The acceleration request may not be met.

  The present invention has been made paying attention to the above problem, and its object is a motor capable of setting a torque upper limit value while sufficiently securing torque even in a transient state in which the engine speed changes. A torque control device is provided.

  To achieve the above object, the present invention is based on a prime mover that generates power and outputs the power from an output shaft to a transmission, a rotational speed detection means that detects the rotational speed of the prime mover, and the rotational speed of the prime mover. A motor-generated torque calculating means for calculating a motor-generated torque in the motor, and an inertia torque calculating means for calculating an inertia torque required when the motor changes in rotation, a motor-generated torque and the inertia torque A transmission input torque calculation means for calculating a motor output torque output from the output shaft and calculating a transmission input torque based on at least the motor output torque, and a transmission input torque is an allowable upper limit of the transmission. When the torque is exceeded, the motor generated torque upper limit value is set so that the transmission input torque becomes smaller than the allowable upper limit torque A prime mover torque upper limit setting means for setting, with a.

  In the motor torque control device of the present invention, the motor output torque output from the output shaft is calculated based on the motor generated torque calculated based on the rotational speed and the inertia torque required for the rotation of the motor. Further, the transmission input torque is calculated based on the prime mover output torque, and when the transmission input torque exceeds the allowable upper limit torque of the transmission, the prime mover generated torque upper limit value is set so that the transmission input torque becomes smaller than the allowable upper limit torque. Was set. Therefore, it is possible to provide a prime mover torque control device capable of setting a torque upper limit value while sufficiently securing torque even in a transient state in which the engine speed changes.

  The best mode for carrying out a motor torque control apparatus according to the present invention will be described below with reference to the drawings.

  First, the configuration of the prime mover torque control device of this embodiment will be described.

  FIG. 1 is a system diagram showing the configuration of a drive system and a control system of a vehicle equipped with a prime mover torque control device of the present embodiment.

  The drive system includes an engine 100 as a prime mover, an engine output shaft 110 connected to the engine 100, and a transmission 120 that shifts and outputs the rotational speed of the engine output shaft 110.

  On the other hand, the control system includes an engine speed sensor (rotation speed detecting means) 200 that detects the engine speed Ne, and an electronic control unit (hereinafter referred to as ECU) 300 that controls the engine 100. .

  The engine 100 generates engine generated torque (motor generated torque) Te in accordance with the engine speed Ne.

  The transmission 120 appropriately changes the rotation input from the engine output shaft 110 by a transmission control device (not shown) and transmits it to driving wheels (not shown).

  The ECU 300 receives information on the engine output shaft rotational speed Ne from the engine rotational speed sensor 200 and controls the engine 100.

  FIG. 2 is a control block diagram in the ECU 300.

  Engine generation torque calculation unit (prime engine generation torque calculation means) 302 calculates engine generation torque Te corresponding to engine speed Ne from engine generation torque map 301 and transmits it to engine output torque calculation unit 304.

  An inertia torque calculation unit (inert torque calculation means) 303 calculates an inertia torque ΔT used to change the rotational speed of the engine 100 itself, and transmits it to the engine output torque calculation unit 304.

  An engine output torque calculation unit (transmission input torque calculation means) 304 calculates an engine output torque (motor output torque) Ti and transmits it to the engine generated torque upper limit setting unit 305.

  The engine output torque upper limit setting unit 306 sets an upper limit value (allowable upper limit torque) Timax of the engine output torque according to the strength of the transmission 120 and transmits it to the engine generated torque upper limit setting unit 305.

  Engine generated torque upper limit value setting unit 305 sets an upper limit value Temax of engine generated torque and transmits it to engine control unit 307.

  The engine control unit (prime motor control means) 307 controls the engine 100 according to the upper limit value Temax of the engine generated torque.

  Next, the operation will be described.

[Outline of engine torque control]
In order to protect the transmission 120, it is necessary to perform torque-down control of the engine generated torque Te generated in the engine 100 when the input torque to the transmission 120 is excessive.

  However, in a transient state such as when the rotation of the engine 100 increases, a part of the engine generated torque Te is used as an inertia torque ΔT for increasing the rotation of the engine 100 itself, and thus is actually output to the engine output shaft 110. The engine output torque Ti input to the transmission 120 is smaller than the engine generated torque Te.

  For this reason, if an engine upper limit value of the engine generation torque Te calculated based on the engine rotation speed Ne is set when the engine rotation speed rises and the torque reduction control is performed, the engine generation torque Te may be excessively reduced. is there. As a result, the engine output torque Ti input to the transmission 120 may not be increased to a torque sufficient for vehicle acceleration, and the driver's acceleration request may not be satisfied.

Therefore, in the present embodiment, the engine generated torque Te is appropriately reduced in consideration of the engine generated torque Te of the engine 100 and the inertia torque ΔT.
[Details of engine torque control]
FIG. 3 is a flowchart showing a flow of engine torque control executed in the ECU 300.

  Here, engine output torque upper limit Timax is set in advance in engine output torque upper limit setting unit 306 in accordance with the strength of transmission 120.

  In step S101, the engine output shaft speed Ne is read from the engine speed sensor 200.

  In step S102, the engine generated torque Te corresponding to the engine speed Ne is read from the engine generated torque map 301 shown in FIG.

In step S103, the inertia torque ΔT is calculated by the equation (1). In the equation (1), Ie represents the rotational inertia of the engine 100, and t represents time.
ΔT = Ie · (dNe / dt) (1)

In step S104, the engine output torque Ti output from the engine 100 to the transmission 120 is calculated by equation (2).
Ti = Te-ΔT (2)

  In step S105, it is determined whether the engine output torque Ti is greater than the engine output torque upper limit value Timax for the transmission 120. If the engine output torque Ti is greater than the engine output torque upper limit value Timax, the process proceeds to step S106, and the engine When the output torque Ti is equal to or less than the engine output torque upper limit Timax, the process proceeds to step S107.

In step S106, the engine generated torque upper limit value Temax of the engine 100 is updated by equation (3). In step S107, the engine generated torque upper limit value Temax of the engine 100 is updated by equation (4). Note that n in equations (3) and (4) represents a preset constant.
Temax = Te-n (3)
Temax = Te + n (4)
This control is executed, for example, at a cycle of 10 [ms], and the engine generated torque upper limit Temax is updated by n = 1 [Nm] each time it is executed.

  FIG. 5 is a time chart showing an example in which torque control of the engine 100 is performed by the prime mover torque control device of the present embodiment. The solid line in FIG. 5 shows the control in this embodiment, and the dotted line shows the conventional control. Only the engine output torque Ti is indicated by a thin solid line and a thin dotted line.

  When the throttle valve opening is operated at time t1, the engine speed Ne increases. At this time, the engine generation torque Te of the engine 100 is generated according to the engine speed Ne.

  When the engine speed Ne increases from time t1 to time t3, the inertia torque ΔT is used to increase the engine speed, so the engine output torque Ti becomes a torque smaller than the engine generated torque Te by the inertia torque ΔT. . At this time, since the engine output torque Ti is smaller than the upper limit value Timax of the engine output torque, the engine generated torque upper limit value Temax is updated so as to increase every calculation cycle. Therefore, the engine output torque Ti increases according to the engine speed Ne.

  When the engine output torque Ti becomes the upper limit value Timax of the engine output torque at time t3, the engine generated torque upper limit value Temax is updated so as to decrease every calculation cycle, and torque cut control is performed.

  When the engine speed Ne is controlled to be constant from time t4 to time t5, the inertia torque ΔT becomes zero, so that the engine generated torque Te and the engine output torque Ti become equal.

  When the engine output torque Ti again falls below the upper limit value Timax of the engine output torque at time t5, the upper limit value Temax of the engine generated torque is updated so as to increase, and the output torque Te is controlled to increase in torque.

  If the torque cut control is performed at the time t2 when the engine generated torque Te reaches the upper limit as in the conventional case, the torque actually input to the transmission 120, such as the engine output torque Ti indicated by the thin dotted line below, is a small torque. Therefore, sufficient vehicle acceleration cannot be performed.

  In this embodiment, the engine output torque Ti actually output from the engine 100 to the transmission 120 can be accurately calculated even in a transient state such as when the engine speed is increased. Therefore, the engine torque can be accurately controlled. In particular, when the engine speed increases during vehicle acceleration, etc., engine torque control is performed in consideration of inertia torque ΔT used for engine speed increase. Occurrence can be suppressed. Further, the engine generated torque upper limit Temax is decreased or increased by 1 [Nm], for example, every 10 [ms] when this control flow is executed, and the engine torque is not suddenly decreased or increased. Reduce shock during control.

  Next, the effect of the prime mover torque control device of the present embodiment will be described.

  (1) In the transient state such as when the engine speed increases, the inertia torque ΔT used to increase the rotation of the engine itself is calculated, and the engine output torque Ti that is actually output from the engine 100 to the transmission 120 is calculated. . Therefore, the engine torque can be accurately controlled. In particular, during vehicle acceleration, engine torque control is performed in consideration of inertia torque ΔT that is used to increase engine rotation, so that the torque required for vehicle acceleration is secured without excessively reducing engine-generated torque Te. However, the generation of excessive torque can be suppressed.

  (2) The inertia torque ΔT is obtained from the product of the engine system inertia Ie and the time differential dNe / dt of the engine speed Ne. Therefore, since the inertia torque ΔT corresponding to the time change of the engine speed Ne can be calculated, the engine output torque Ti can also be calculated according to the time change, while ensuring sufficient torque for vehicle acceleration. Therefore, it is possible to perform engine torque control that suppresses generation of excessive torque.

  (3) An upper limit value Timax corresponding to the strength of the transmission 120 is set for the engine output torque Ti actually input to the transmission 120, and the upper limit value Temax of the engine generated torque Te is set according to the upper limit value Timax. The upper limit value of was set. Therefore, control is performed so that a larger engine output torque Ti is input to the transmission 120 within a range not exceeding the strength of the transmission 120, so that excessive torque is generated while ensuring sufficient torque for vehicle acceleration. Suppressed engine torque control can be performed.

  (4) The engine generated torque upper limit Temax is decreased or increased by a certain amount for each control cycle. Therefore, the shock at the time of engine torque control can be reduced without a sudden decrease or increase in torque.

  First, the configuration of the prime mover torque control device of this embodiment will be described.

  In this embodiment, the torque converter 130, the automatic transmission 150, and the like are newly provided in the first embodiment. The same reference numerals are given to the same components as those in the first embodiment, and the description thereof is omitted.

  FIG. 6 is a system diagram showing the configuration of the drive system and the control system of the vehicle equipped with the prime mover torque control device of the present embodiment.

  As a drive system, an engine 100 as a prime mover, an engine output shaft 110 connected to the engine 100, a torque converter 130 that doubles the input torque, and a torque converter read as a turbine runner of the torque converter 130 An output shaft 140 and an automatic transmission 150 that shifts and outputs the rotational speed of the torque converter output shaft 140 are provided.

  On the other hand, as a control system, an engine speed sensor 200 that detects the rotational speed of the engine output shaft 110, that is, the engine rotational speed Ne, and a torque converter output shaft rotational speed sensor 210 that detects the rotational speed Nt of the torque converter output shaft 140. And an ECU 300 that controls the engine 100.

  The torque converter 130 outputs a torque obtained by multiplying the input torque by a torque ratio tr. This torque ratio tr is a value corresponding to the speed ratio e (= transmission input shaft rotational speed Nt / engine rotational speed Ne).

  The automatic transmission 150 shifts the rotation input from the torque converter output shaft 140 as appropriate by a transmission control device (not shown) and transmits it to driving wheels (not shown).

  ECU 300 receives information about engine speed Ne and torque converter output shaft speed Nt from engine speed sensor 200 and torque converter output shaft speed sensor 210, and controls engine 100.

  FIG. 7 shows a control block in the ECU 300.

  The engine generation torque calculation unit 302 calculates an engine generation torque Te corresponding to the engine speed Ne from the engine generation torque map 301 and transmits it to the engine output torque calculation unit 304.

  The inertia torque calculation unit 303 calculates an inertia torque ΔT used to change the rotational speed of the engine 100 itself, and transmits it to the engine output torque calculation unit 304.

  The engine output torque calculation unit 304 calculates the engine output torque Ti and transmits it to the torque converter output torque calculation unit 310.

  The torque ratio calculation unit 309 calculates a torque ratio tr corresponding to the speed ratio e from the torque ratio map 308, and transmits the torque ratio tr to the torque converter output torque calculation unit 310.

  Torque converter output torque calculation section 310 calculates torque converter output torque Tt and transmits it to engine generated torque upper limit setting section 305.

  Torque converter output torque upper limit value setting unit 311 sets an upper limit value Ttmax of torque converter output torque corresponding to the strength of automatic transmission 150 and transmits it to engine generated torque upper limit value setting unit 305.

  Engine generated torque upper limit value setting unit 305 sets an upper limit value Temax of engine generated torque and transmits it to engine control unit 307.

  The engine control unit 307 controls the engine 100 according to the upper limit value Temax of engine generated torque.

  Next, the operation will be described.

[Outline of engine torque control]
In order to protect the automatic transmission 150, when the input torque to the automatic transmission 150 is excessive, it is necessary to perform torque-down control of the engine generated torque Te generated in the engine 100.

  However, as in the first embodiment, in a transient state such as when the rotation of the engine 100 increases, a part of the engine generated torque Te is used as an inertia torque ΔT for increasing the rotation of the engine 100 itself. That is, the engine output torque Ti that is actually output to the engine output shaft 110 is smaller than the engine generated torque Te.

In the case of the vehicle having the torque converter 130 as in this embodiment, the torque converter output torque Tt obtained by doubling the engine output torque Ti is input to the automatic transmission 150. For this reason, as in the first embodiment, when the engine generation torque Te is set to the upper limit value calculated based on the engine speed Ne when the engine speed is increased and the torque reduction control is performed, the engine generation torque Te is excessively reduced. There is a risk of going. As a result, sufficient torque may not be input to the torque converter 130, and the engine output torque Tt input to the automatic transmission 150 may not increase to a torque sufficient for vehicle acceleration to meet the driver's acceleration request. There is.
[Details of engine torque control]
FIG. 8 is a flowchart showing a flow for determining the engine generated torque upper limit value Temax executed in the ECU 300.

  Here, in ECU 300, torque converter output torque upper limit value Ttmax is set in advance according to the strength of automatic transmission 150.

  In step S201, the rotational speed Ne of the engine output shaft 110 is read from the engine rotational speed sensor 200, and the rotational speed Nt of the torque converter output shaft 140 is read from the torque converter output shaft rotational speed sensor 210.

  In step S202, the engine generated torque Te corresponding to the engine speed Ne is read from the engine generated torque map 301 shown in FIG. Further, the torque ratio tr corresponding to the speed ratio e (= Ne / Nt) is read from the torque ratio map 308.

In step S203, the inertia torque ΔT is calculated from the equation (1). Here, the inertia torque ΔT when the engine speed is increasing is positive, and the inertia torque ΔT when the engine speed is decreasing is negative. In equation (1), Ie is inertia of the engine system, and t is time.
ΔT = Ie · (dNe / dt) (1)

In step S204, the engine output torque Ti output from the engine 100 to the torque converter 130 is calculated by equation (2).
Ti = Te-ΔT (2)

In step S205, the torque converter output torque Tt input from the torque converter 130 to the automatic transmission 150 is calculated by equation (5).
Tt = Ti · tr (5)

  In step S206, it is determined whether or not the torque converter output torque Tt is greater than the torque converter output torque upper limit value Ttmax for the automatic transmission 150. If the torque converter output torque Tt is greater than the engine output torque upper limit value Ttmax, the process proceeds to step S207. When the torque converter output torque Tt is equal to or less than the torque converter output torque upper limit value Ttmax, the process proceeds to step S208.

In step S207, the engine generated torque upper limit value Temax of the engine 100 is updated by equation (3). In step S208, the engine generated torque upper limit value Temax of the engine 100 is updated by equation (4). Note that n in equations (3) and (4) represents a preset constant.
Temax = Te-n (3)
Temax = Te + n (4)
This control is executed, for example, at a cycle of 10 [ms], and the engine generated torque upper limit Temax is updated by n = 1 [Nm] each time it is executed.

  FIG. 10 is a time chart showing an example in which torque control of the engine 100 is performed by the prime mover torque control device of the present embodiment. The solid line in FIG. 10 shows the control in this embodiment, and the dotted line shows the conventional control. Only the engine output torque Ti is indicated by a thin solid line and a thin dotted line.

  When the throttle valve opening is operated at time t6, the engine speed Ne increases. At this time, the engine generation torque Te of the engine 100 is generated according to the engine speed Ne.

  When the engine speed Ne increases from time t6 to time t8, the inertia torque ΔT is used to increase the engine speed, so the engine output torque Ti output from the engine 100 to the torque converter 130 is the engine generated torque Te The torque is smaller than the inertia torque ΔT. At this time, as the engine output torque Ti increases, the torque converter output torque Tt to the automatic transmission 150 also increases. However, since the torque is smaller than the upper limit value Ttmax, the engine generated torque upper limit value Temax is calculated every time the calculation cycle occurs. It is updated so as to increase, and increases according to the engine speed Ne.

  When the torque converter output torque Tt becomes the torque converter output torque upper limit value Ttmax at time t8, the engine generated torque upper limit value Temax is updated so as to decrease every time the calculation cycle is performed, and torque cut control is performed.

  When the engine speed Ne is controlled to be constant from time t8 to time t9, the inertia torque ΔT becomes zero, so that the engine generated torque Te and the engine output torque Ti become equal.

  When the torque converter output torque Tt falls below the torque converter output torque upper limit value Ttmax again at time t9, the engine generated torque upper limit value Temax is updated so as to increase, and the output torque Te is controlled to increase in torque.

  When the torque cut control is performed at time t7 as determined by only the engine generated torque Te as in the conventional case, the torque actually input to the automatic transmission 150 is small like the torque converter output torque Tt indicated by the dotted line thereafter. Due to the torque, sufficient vehicle acceleration cannot be performed.

  In this embodiment, the engine output torque Ti that is actually output from the engine 100 to the torque converter 130 can be accurately calculated even in a transient state such as when the engine speed increases, and the accurate torque converter output can be calculated from the engine output torque Ti. Torque Tt can be calculated. Therefore, the engine torque can be accurately controlled. In particular, when the engine speed increases during vehicle acceleration, etc., engine torque control is performed in consideration of inertia torque ΔT used for engine speed increase. Occurrence can be suppressed. Further, the engine generated torque upper limit Temax is decreased or increased by 1 [Nm], for example, every 10 [ms] when this control flow is executed, and the engine torque is not suddenly decreased or increased. Reduce shock during control.

  Next, the effect of the prime mover torque control device of the present embodiment will be described.

  (5) The torque converter output torque Tt actually input to the automatic transmission 150 is calculated, and an upper limit value Ttmax corresponding to the strength of the automatic transmission 150 is set for the torque converter output torque Tt. The upper limit value Temax of the engine generated torque Te is set according to the value Ttmax. Therefore, the torque converter output torque Tt is controlled to be input to the automatic transmission 150 within a range that does not exceed the strength of the automatic transmission 150. Therefore, an excessive torque can be secured while ensuring sufficient torque for vehicle acceleration. It is possible to perform engine torque control while suppressing the occurrence of.

  As mentioned above, although the motor | power_engine torque control apparatus of this invention has been demonstrated based on Example 1 or Example 2, it is not restricted to these Examples about concrete structure, Each claim of a claim Design changes and additions are allowed without departing from the spirit of the invention.

  For example, although the engine 100 is used as the prime mover in the first and second embodiments, an electric motor may be used.

  The present invention not only sets the upper limit torque according to the strength of the transmission and performs the prime mover torque control, but also in the prime mover torque control for reducing the torque in order to reduce the shock when a sudden large torque is generated. Can also be used.

1 is an overall system diagram illustrating a drive system and a control system to which a prime mover torque control device according to a first embodiment is applied. FIG. 3 is a control block diagram in the ECU according to the first embodiment. 3 is a flowchart showing a flow of prime mover torque control according to the first embodiment. 6 is an engine generated torque map showing a relationship between an engine speed Ne and an engine generated torque Te according to the first and second embodiments. 3 is a time chart of prime mover torque control according to the first embodiment. It is a whole system diagram which shows the drive system and control system to which the prime mover torque control apparatus based on Example 2 was applied. FIG. 6 is a control block diagram in the ECU according to the second embodiment. 6 is a flowchart showing a flow of prime mover torque control according to the second embodiment. 10 is a torque ratio map showing a relationship between a speed ratio e and a torque ratio tr according to the second embodiment. 6 is a time chart of prime mover torque control according to the second embodiment.

Explanation of symbols

100 engine
110 Engine output shaft
120 transmission
130 Torque converter
150 automatic transmission
200 Engine speed sensor
302 Engine generated torque calculator
303 Inert shuttle calculator
304 Engine output torque calculator
305 Engine generated torque upper limit setting part
306 Engine output torque upper limit setting part
309 Torque ratio calculator
310 Torque converter output torque calculator
311 Torque converter output torque upper limit setting section

Claims (3)

A prime mover that generates power and outputs the power from the output shaft to the transmission;
A rotational speed detection means for detecting the rotational speed of the prime mover;
A motor generating torque calculating means for calculating a motor generating torque in the motor based on the number of rotations of the motor;
In the motor torque control device comprising:
An inertia torque calculation means for calculating an inertia torque required when the rotational speed of the prime mover changes,
Transmission input torque calculation means for calculating a motor output torque output from the output shaft from the motor generated torque and the inertia torque, and calculating a transmission input torque based on at least the motor output torque;
Prime mover generated torque upper limit setting means for setting the prime mover generated torque upper limit so that the transmission input torque becomes smaller than the allowable upper limit torque when the transmission input torque exceeds the allowable upper limit torque of the transmission; ,
A prime mover torque control device comprising: The prime mover torque control device according to claim 1,
The inertia torque calculation device according to claim 1, wherein the inertia torque calculation means uses an inertia torque as a product of a rotational inertia of the prime mover and a value obtained by differentiating the rotational speed of the output shaft with respect to time. In the motor torque control device according to claim 1 or 2,
A torque converter that increases the prime mover output torque and outputs a torque converter output torque;
Torque ratio calculating means for calculating a torque ratio of the torque converter;
Torque converter output torque calculation means for calculating a product of the motor output torque and the torque ratio as a torque converter output torque;
With
The prime mover torque control device, wherein the transmission input torque is the torque converter output torque.

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