JP6237385B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a technical field of a vehicle control device mounted on a vehicle including a so-called regenerative brake such as a hybrid vehicle or an electric vehicle.

  As a device of this type, for example, when the motor rotational speed belongs to the extremely low speed region or a region near it as a result of regenerative braking, even if the motor rotational speed detection value fluctuates due to motor vibration, A device that prohibits command and output of torque and regenerative torque has been proposed (see Patent Document 1).

JP-A-8-140213

  By the way, the value output from the rotation speed sensor for detecting the motor rotation speed is often affected by disturbance. For this reason, there is a technical problem that the detection accuracy of the motor rotation speed is not sufficient with only the rotation speed sensor. In the background art described above, it is extremely difficult to solve this technical problem.

  The present invention has been made in view of the above-described problems, for example, and an object of the present invention is to provide a vehicle control device that can improve the accuracy of the motor rotational speed detected by the rotational speed sensor.

  In order to solve the above problems, a first vehicle control device of the present invention includes a motor / generator capable of outputting a regenerative torque to an axle, a rotational speed sensor for detecting the rotational speed of the motor / generator, and the axle. And a vehicle brake control means for controlling the motor / generator and the hydraulic brake, wherein the vehicle brake control means includes: A twist angle of the axle is calculated based on the output regenerative torque and a braking force applied by the hydraulic brake, and a vehicle speed is calculated based on the calculated twist angle and the detected rotational speed. presume.

  According to the first vehicle control apparatus of the present invention, the vehicle control apparatus includes a motor / generator, a rotation speed sensor, a hydraulic brake, and vehicle braking control means.

  The motor / generator is configured to output regenerative torque to the axle of the vehicle. For example, a rotational speed sensor such as a resolver detects the rotational speed of the motor / generator. The hydraulic brake is configured to be able to apply a braking force to the axle.

  For example, vehicle braking control means including a memory, a processor, etc. controls the motor / generator and the hydraulic brake. Particularly in the present invention, the vehicle braking control means calculates the torsion angle of the axle based on the regenerative torque output from the motor / generator and the braking force applied by the hydraulic brake, and detects the calculated torsion angle and the detected The vehicle speed is estimated based on the determined rotational speed.

  Here, according to the inventor's research, the following matters have been found. That is, when the rotation speed of the motor / generator is used, the vehicle speed can be estimated with higher accuracy than when the output signal from the wheel speed sensor that detects the rotation speed of the wheel connected to the axle is used. it can. On the other hand, the rotational speed sensor that detects the rotational speed of the motor / generator is affected by disturbance, and an error in the detected rotational speed becomes relatively large. Then, for example, when the vehicle speed estimated based on the number of revolutions of the motor / generator is not zero when the vehicle is decelerated and stopped by so-called regenerative braking, even though the actual vehicle speed is zero. There is a possibility that the regenerative torque will continue to be output from the motor / generator, and the vehicle may move backward against the driver's intention.

  Therefore, the inventor of the present application pays attention to the fact that when a torque is applied to the axle connected to the drive wheel, the axle causes a torsional motion. The vehicle speed is estimated based on the rotation speed of the motor / generator. More specifically, for example, the vehicle braking control means corrects the rotational speed of the motor / generator based on the twist angle of the axle, and estimates the vehicle speed based on the corrected rotational speed.

  As a result, according to the first vehicle control apparatus of the present invention, the accuracy of the rotational speed of the motor / generator detected by the rotational speed sensor can be improved.

  In order to solve the above problems, a second vehicle control device of the present invention includes a motor / generator capable of outputting a regenerative torque to an axle, a rotational speed sensor for detecting the rotational speed of the motor / generator, and the axle. A vehicle brake control means for controlling the motor / generator and the hydraulic brake, wherein the rotational speed sensor is at least one of the power transmission paths. The vehicle braking control means calculates a roll angle related to the power transmission path based on the regenerative torque output from the motor / generator, and the calculated roll angle The vehicle speed is estimated based on the detected rotational speed.

  According to the second vehicle control apparatus of the present invention, the rotational speed sensor is installed in a case covering at least a part of the power transmission path. That is, the rotation speed sensor is installed in a so-called power train case.

  The vehicle braking control means calculates a roll angle related to the power transmission path based on the regenerative torque output from the motor / generator, and estimates the vehicle speed based on the calculated roll angle and the detected rotational speed. .

  Here, according to the inventor's research, the following matters have been found. That is, when the motor / generator is regeneratively controlled, the so-called power train is subjected to the reaction of the regenerative torque output from the motor / generator, so that a strong load is applied to the engine mount, and the so-called power train swings. Since the rotational speed sensor is fixed to a so-called power train case, the rotational displacement of the so-called power train is superimposed on the rotational speed detected by the rotational speed sensor.

  Therefore, in the present invention, as described above, the vehicle speed is estimated by the vehicle braking control means based on the so-called power train roll angle and the rotational speed of the motor / generator. More specifically, for example, the vehicle braking control means corrects the rotational speed of the motor / generator based on the so-called power train roll angle, and estimates the vehicle speed based on the corrected rotational speed.

  As a result, according to the second vehicle control apparatus of the present invention, the accuracy of the rotational speed of the motor / generator detected by the rotational speed sensor can be improved.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

1 is a block diagram illustrating a configuration of a vehicle according to a first embodiment. It is a conceptual diagram which shows the concept of the vehicle speed estimation which concerns on 1st Embodiment. It is a conceptual diagram which shows the concept of the twist angle estimation of the drive shaft which concerns on 1st Embodiment. It is a figure which shows the rotational inertia system from motor generator MG2 to a driving wheel, and a corresponding character type. It is an example of a stroke-torque conversion map. It is a flowchart which shows the vehicle speed estimation process which concerns on 1st Embodiment. It is a conceptual diagram which shows the concept of rocking | fluctuation of a power train. It is a conceptual diagram which shows the concept of the vehicle speed estimation which concerns on 2nd Embodiment. It is an example of an MG2 torque-roll angle conversion map. It is a flowchart which shows the vehicle speed estimation process which concerns on 2nd Embodiment. It is a conceptual diagram which shows the concept of calculation of the roll angle which concerns on the modification of 2nd Embodiment.

  An embodiment according to a vehicle control device of the present invention will be described with reference to the drawings.

<First Embodiment>
1st Embodiment which concerns on the control apparatus of the vehicle of this invention is described with reference to FIG. 1 thru | or FIG.

(Vehicle configuration)
The configuration of the vehicle according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a vehicle according to the first embodiment.

  In FIG. 1, a vehicle 1 includes an engine ENG, motor generators MG1 and MG2, and planetary gear mechanisms 11 and 12.

  The planetary gear mechanism 11 includes a sun gear s1, a ring gear r arranged concentrically with the sun gear s1, a plurality of planetary gears p1 meshing with the sun gear s1 and meshing with the ring gear r, and the plurality of planetary gears p1. And a carrier c1 that holds the motor so as to rotate and revolve freely.

  The planetary gear mechanism 12 includes a sun gear s2, a ring gear r arranged concentrically with the sun gear s2, and a plurality of planetary gears p2 meshing with the sun gear s2 and meshing with the ring gear r. . In the planetary gear mechanism 12, the rotation shaft of each of the plurality of planetary gears p2 is fixed to a power train case (not shown).

  The carrier shaft of the planetary gear mechanism 11 is connected to the crankshaft of the engine ENG. The sun gear shaft of the planetary gear mechanism 11 is connected to the rotation shaft of the motor / generator MG1. The sun gear shaft of the planetary gear mechanism 12 is connected to the motor / generator MG2.

  The power output to the ring gear r is transmitted to the drive wheels via the speed reducer 13, the differential gear 14 and the drive shaft 15.

  The vehicle 1 further includes an MGECU (Electronic Control Unit) 21 that controls the motor generators MG 1 and MG 2, and a brake ECU 22 that controls the hydraulic brake actuator 23. The MGECU 21 and the brake ECU 22 are configured to be able to communicate with each other.

  Particularly in the vehicle 1, during deceleration, the motor / generator MG 2 is regeneratively controlled by the MGECU 21 and the brake actuator 23 is controlled by the brake ECU 22. That is, the vehicle 1 is decelerated by so-called cooperative regenerative braking.

  In so-called cooperative regenerative braking, for example, the ratio between the regenerative torque of the motor / generator MG2 and the braking force by the brake actuator 23 is changed according to the vehicle speed. Therefore, if the estimation accuracy of the vehicle speed can be improved, for example, the kinetic energy at the time of deceleration of the vehicle 1 recovered as electric power by the motor / generator MG2 can be increased.

  Here, the vehicle speed estimation method includes, for example, a method using an output signal of a wheel speed sensor (not shown) provided on a drive wheel, a method of estimating based on the number of revolutions of the motor / generator MG2, and the like. .

  The vehicle speed estimated based on the rotation speed of the motor / generator MG2 has higher accuracy than the vehicle speed estimated using the output signal of the wheel speed sensor. However, a rotation speed sensor (not shown) that detects the rotation speed of the motor / generator MG2 is often affected by disturbance, and the error of the estimated vehicle speed is often relatively large.

  In the present embodiment, paying attention to the fact that when torque (for example, regenerative torque, braking force, etc.) is applied to the drive shaft 15, the drive speed is estimated by the following method. The

(Vehicle speed estimation)
In the vehicle 1 configured as described above, a vehicle speed estimation process performed particularly when the vehicle 1 is decelerated will be described with reference to FIG. FIG. 2 is a conceptual diagram showing the concept of vehicle speed estimation according to the first embodiment.

  As shown in FIG. 2, in the present embodiment, the twist angle of the drive shaft 15 is estimated by an observer, and the motor / generator MG2 detected by a rotational speed sensor (not shown) based on the estimated twist angle. Is corrected, the vehicle speed of the vehicle 1 is estimated.

  A method for estimating the twist angle of the drive shaft 15 will be described with reference to FIGS. FIG. 3 is a conceptual diagram showing the concept of estimation of the twist angle of the drive shaft according to the first embodiment. FIG. 4 is a diagram showing a rotary inertia system from the motor / generator MG2 to the drive wheels and a corresponding character expression.

As shown in FIG. 3, in this embodiment, the torsion angle of the drive shaft 15 is estimated by inputting the MG2 torque τ _mg2 of the motor / generator MG2 and the brake torque τ _b of the brake actuator 23 to the observer. The

Here, the observer sets the gear ratio related to the speed reducer 13 (that is, the speed reduction ratio of the motor / generator MG2) to ρ _r , the gear ratio related to the differential gear 14 to i _diff , and the rotation angle of the speed reduction gear (speed reducer 13). θ _op , the rotational angle of the drive wheel is θ _body1 , the total rotational inertial mass of the reduction gear and the differential gear is I _op , the equivalent rotational inertial mass of the drive wheel of the vehicle 1 is I _body1 , and the combined elastic modulus of the tire and the drive shaft 15 _Is K _ds1 , and the combined viscosity coefficient of the tire and the drive shaft 15 is C _ds1 , the following equations (1) to (4) can be expressed.

The MG2 torque τ _mg2 may be acquired from the MGECU 21. Further, the brake torque τ _b may be obtained from a stroke-torque conversion map (see FIG. 5) stored in advance in the brake ECU 22 and a stroke amount of a brake pedal (not shown) and a stroke-torque conversion map. . The brake torque τ _b is transmitted to the MGECU 21 via the brake ECU 22 and used for calculating the torsion angle of the drive shaft 15 by the observer (that is, the mathematical expressions (1) to (4)).

  As a result, in the present embodiment, it is possible to accurately estimate the vehicle speed of the vehicle 1 by reducing an error in the rotational speed of the motor / generator MG2 due to disturbance. Therefore, for example, the amount of kinetic energy recovered as electric power can be increased by so-called cooperative regenerative braking, which is very advantageous in practice.

  Next, the vehicle speed estimation process according to the present embodiment will be described with reference to the flowchart of FIG.

  In FIG. 6, the MGECU 21 first determines whether or not the ignition is ON (step S101). When it is determined that the ignition is OFF (step S101: No), the MGECU 21 once ends the process, and performs the process of step S101 again after a predetermined time has elapsed.

  When it is determined that the ignition is ON, the MGECU 21 converts the rotational speed of the motor / generator MG2 detected by the rotational speed sensor into the rotational speed of the drive wheel (step S102). It should be noted that various known modes can be applied to the conversion from the rotational speed of the motor / generator MG2 to the rotational speed of the drive wheels, and therefore, detailed description thereof is omitted.

Next, the MGECU 21 acquires a torque value (τ _mg2 ) of the motor / generator MG2 such as a regenerative torque value (step S103). Subsequently, the MGECU 21 acquires a brake torque estimated value (τ _b ) from the brake ECU 22 (step S104).

Next, based on the acquired torque value (τ _mg2 ) and brake torque estimated value (τ _b ), the MGECU 21 uses the observer (that is, the mathematical expressions (1) to (4) above) to twist the drive shaft 15. Is estimated (step S105).

  Next, the MGECU 21 corrects the rotational speed of the drive wheel (that is, the rotational speed of the motor / generator MG2 after the return) based on the estimated twist angle (step S106). Subsequently, the MGECU 21 estimates the vehicle speed of the vehicle 1 based on the corrected rotational speed of the drive wheels (step S107).

  The “MG ECU 21” and the “brake ECU 22” according to the present embodiment are examples of the “braking control unit” according to the present invention.

Second Embodiment
A second embodiment of the vehicle control apparatus of the present invention will be described with reference to FIGS. The second embodiment is the same as the configuration of the first embodiment except that the vehicle speed estimation process is partially different. Accordingly, the description of the second embodiment that is the same as that of the first embodiment is omitted, and common portions in the drawings are denoted by the same reference numerals, and only the points that are basically different are shown in FIGS. The description will be given with reference.

When a so-called regenerative brake is used during deceleration of the vehicle 1, the power train receives a reaction of MG2 torque τ _mg2 output from the motor / generator MG2. Then, a strong load is applied to the engine mount, and the power train swings, for example, as shown in FIG. 7 (in FIG. 7, the rotation angle of the power train is “θ _pt ”). FIG. 7 is a conceptual diagram showing the concept of power train swinging.

  In the present embodiment, a rotation speed sensor (not shown) for detecting the rotation speed of the motor / generator MG2 is fixed to a case (not shown) of the power train. For this reason, the rotational angle (rotational displacement) of the power train is also superimposed on the output value of the rotational speed sensor. Then, the accuracy of the vehicle speed estimated based on the rotation speed of the motor / generator MG2 is lowered.

Therefore, in the present embodiment, as shown in FIG. 8, the roll angle (θ _pt ) of the power train is estimated, and after the rotational speed of the motor / generator MG2 is corrected by the estimated roll angle, the vehicle 1 The vehicle speed is estimated.

  Here, the torque acting on the power train during the regeneration of the motor / generator MG2 becomes the regenerative torque reaction force received by the stator of the motor / generator MG2. The regenerative torque reaction force can be easily estimated from the current value, for example, by the MGECU 21.

  For this reason, in this embodiment, the MG2 torque-roll angle conversion map (see FIG. 9) is stored in advance in the MGECU 21, and the roll angle of the power train is determined from the regenerative torque reaction force and the MG2 torque-roll angle conversion map. Desired.

  Next, the vehicle speed estimation process according to the present embodiment will be described with reference to the flowchart of FIG.

  In FIG. 10, the MGECU 21 first determines whether or not the ignition is ON (step S201). When it is determined that the ignition is OFF (step S201: No), the MGECU 21 once ends the process, and performs the process of step S201 again after a predetermined time has elapsed.

  When it is determined that the ignition is ON, the MGECU 21 acquires the rotational speed of the motor / generator MG2 detected by the rotational speed sensor (step S202). In parallel with or in parallel with the processing of step S202, the MGECU 21 acquires the regenerative torque reaction force of the motor / generator MG2 (step S203).

Next, the MGECU 21 calculates the roll angle (θ _pt ) of the power train from the acquired regenerative torque reaction force and the MG2 torque-roll angle conversion map (see FIG. 9). Subsequently, the MGECU 21 corrects the rotational speed of the motor / generator MG2 based on the calculated roll angle (step S205).

  Next, the MGECU 21 converts the corrected rotational speed of the motor / generator MG2 into the rotational speed of the drive wheels (step S206). Subsequently, the MGECU 21 estimates the vehicle speed of the vehicle 1 based on the rotational speed of the drive wheels (step S207).

<Modification>
Next, a modification of the second embodiment will be described with reference to FIG. FIG. 11 is a conceptual diagram showing a concept of calculating a roll angle according to a modification of the second embodiment.

  In the second embodiment described above, the roll angle is obtained using an MG2 torque-roll angle conversion map as shown in FIG. However, for example, when the rotational inertial mass of the power train is relatively large or the regenerative torque increases suddenly, there is a possibility that it cannot sufficiently respond (that is, the error of the estimated roll angle may increase). is there).

  Therefore, in this modification, the roll angle of the power train is estimated in consideration of the rotational motion of the power train.

Specifically, first, the roll angle (rotation angle) of the power train is θ _pt , the rotational inertial mass of the power train is I _pt , the regenerative torque reaction force (MG2 torque) of the motor / generator MG2 is τ _mg2 , and the engine mount _Assuming that the load torque is τ _mt , the combined elastic coefficient of the engine mount is K _mt , and the combined viscosity coefficient of the engine mount is C _mt , a transfer function is derived from the equation of motion of the following equation (5).

Next, the roll angle θ _pt is calculated based on the regenerative torque reaction force τ _mg2 of the motor / generator MG2 and the derived transfer function (see FIG. 11).

  With this configuration, the vehicle speed can be accurately estimated based on the number of revolutions of the motor / generator MG2, for example, even in a hybrid vehicle having a large displacement engine or when the regenerative torque suddenly increases. Can do.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and control of the vehicle accompanying such changes. The apparatus is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 11, 12 ... Planetary gear mechanism, 13 ... Reduction gear, 14 ... Differential gear, 15 ... Drive shaft, 21 ... MGECU, 22 ... Brake ECU, 23 ... Brake actuator, ENG ... Engine, MG1, MG2 ... Motor ·generator

Claims (2)

A motor / generator capable of outputting a regenerative torque to an axle; a rotational speed sensor for detecting the rotational speed of the motor / generator; a hydraulic brake capable of applying a braking force to the axle; the motor / generator and the hydraulic brake; Vehicle braking control means for controlling, a vehicle control device comprising:
The vehicle braking control means calculates a torsion angle of the axle based on a regenerative torque output from the motor / generator and a braking force applied by the hydraulic brake, the calculated torsion angle, A vehicle control device that estimates a vehicle speed based on the detected number of revolutions. A motor / generator capable of outputting a regenerative torque to an axle; a rotational speed sensor for detecting the rotational speed of the motor / generator; a hydraulic brake capable of applying a braking force to the axle; the motor / generator and the hydraulic brake; Vehicle braking control means for controlling, a vehicle control device comprising:
The rotational speed sensor is installed in a case covering at least a part of the power transmission path,
The vehicle braking control means calculates a roll angle related to the power transmission path based on the regenerative torque output from the motor / generator, and based on the calculated roll angle and the detected rotation speed. A vehicle control device that estimates a vehicle speed.

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