JP5195542B2 - Control device for electric vehicle - Google Patents

Description

  The present invention relates to a control device for an electric vehicle including a drive motor, a stepped transmission, and drive wheels in order from the upstream side of the drive system.

  Conventionally, as a hybrid drive device, torque of a main power source is transmitted to an output member, and torque is transmitted from the output member to a drive wheel via a differential. On the other hand, an assist power source capable of power running control for outputting driving force for traveling or regenerative control for recovering energy is provided, and this assist power source is connected to an output member via a transmission. As a result, the transmission torque between the assist power source and the output member is increased or decreased according to the gear ratio set by the transmission (see, for example, Patent Document 1).

  Specifically, when switching from the low speed stage to the high speed stage, the second brake is released from the engaged state, and at the same time the first brake is engaged, so that the low speed stage is changed to the high speed stage. Shifting was being performed. In this shifting process, the torque capacity at each brake decreases, so the torque applied from the second motor generator to the output shaft is limited to the torque capacity at each brake.

Japanese Patent Laid-Open No. 2004-203220

  However, in a conventional hybrid drive device, if a friction engagement device is used for the speed change mechanism disposed between the rotating electrical machine and the output shaft, drag loss is caused by the clutch of the speed stage that is not fastened. Occurred, the required driving force increases, the required output of the engine increases, and the fuel consumption increases. In addition, the operating point of the rotating electrical machine also changes depending on the gear position, and the operating point changes on the rotating electrical machine efficiency map, so that the operating efficiency changes, and accordingly, the motor loss changes and the power consumption increases. It was.

  The present invention has been made paying attention to the above-mentioned problem, and it is possible to reduce consumption of driving energy by performing shift control for selecting a shift stage in consideration of transmission loss and motor loss during traveling. An object of the present invention is to provide a control device for an electric vehicle.

In order to achieve the above object, the control apparatus for an electric vehicle according to the present invention includes a drive motor, a stepped transmission, and drive wheels in order from the upstream side of the drive system. A shift control means is provided that includes a mechanism and a shift element, and that shifts to a selected gear position by switching control of engagement / release of the shift element when a shift condition is established.
In this electric vehicle control device, the shift control means predicts a transmission loss of the stepped transmission at each shift speed, predicts a motor loss of the drive motor at each shift speed, and predicts a transmission loss predicted. And the gear position that minimizes the sum of the motor losses is selected, and when the selected gear position is different from the current gear position, the gear is shifted to the selected gear position.

Therefore, in the control apparatus for an electric vehicle according to the present invention, the transmission control means predicts the transmission loss of the stepped transmission at each shift stage and the motor loss of the drive motor at each shift stage during travel. Is done. Then, a gear stage that minimizes the sum of the predicted transmission loss and motor loss is selected, and when the selected gear stage is different from the current gear stage, a shift is made to the selected gear stage.
That is, instead of normal shift control based on vehicle information (vehicle speed, accelerator opening, battery charge capacity, etc.), by selecting a shift stage that minimizes the sum of predicted transmission loss and motor loss, for example, In the case of an electric vehicle, the amount of power consumed by the drive motor can be reduced, and in the case of a hybrid vehicle, the amount of fuel consumed by the engine and the amount of power consumed by the drive motor can be reduced.
As a result, it is possible to reduce the amount of drive energy consumed by performing shift control for selecting a gear position in consideration of transmission loss and motor loss during traveling.

1 is an overall system diagram illustrating a configuration of a drive system and a control system of a hybrid vehicle (an example of an electric vehicle) to which a control device of Example 1 is applied. FIG. 4 is a velocity diagram showing the rotation speed (rotation speed) of each rotation element in a drive system of a hybrid vehicle to which the control device of Embodiment 1 is applied, with the vertical axis. 4 is a flowchart showing a flow of a shift control process executed by the hybrid controller 48 of the first embodiment. It is a figure which shows the driving force map for every transmission mode (low mode, high mode) in the transmission control of Example 1, the operating point in low mode, and the operating point in high mode. It is a figure which shows the motor efficiency map which overlap | superposed the maximum motor output line in the shift control of Example 1, the motor operating point in the low mode, and the motor operating point in the high mode. It is a whole system figure which shows the structure of the drive system and control system of the hybrid vehicle (an example of an electric vehicle) to which the control apparatus of Example 2 was applied. FIG. 6 is a velocity diagram showing the rotation speed (number of rotations) of each rotation element in a drive system of a hybrid vehicle to which the control device of the second embodiment is applied with the vertical axis. 6 is a flowchart showing a flow of a shift control process executed by a hybrid controller 48 of the second embodiment. FIG. 10 is a diagram illustrating a driving force map for each shift mode (low mode, middle mode, high mode), an operating point in the low mode, an operating point in the middle mode, and an operating point in the high mode in the shift control according to the second embodiment. . 1 is an overall system diagram showing a configuration example of a drive system and a control system of an electric vehicle (an example of an electric vehicle) to which a control device of the present invention is applied.

  Hereinafter, the best mode for realizing an electric vehicle control device of the present invention will be described based on Example 1 and Example 2 shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram illustrating a configuration of a drive system and a control system of a hybrid vehicle (an example of an electric vehicle) to which the control device of the first embodiment is applied. The drive system configuration and control system configuration will be described below with reference to FIG.

  As shown in FIG. 1, the drive system of the hybrid vehicle of the first embodiment includes an engine 1, a damper 2, a first motor generator 3, an oil pump 4, a second motor generator 5 (drive motor), A step transmission 6, a friction clutch 7 (transmission element), a dog clutch 8 (transmission element), and a planetary gear device 10 are provided.

  The engine 1 distributes the output torque to the power generation torque and the running torque for the first motor generator 3 by the planetary gear unit 10. Then, the second motor generator 5 outputs torque via the stepped transmission 6 using the electric power generated by the first motor generator 3. Then, the output torque from the planetary gear device 10 and the output torque from the stepped transmission 6 are combined by the final output shaft 23.

  The planetary gear device 10 is constituted by a single pinion type planetary gear having a ring gear 11, a pinion 12, a sun gear 13, and a carrier 14 that supports the pinion 12. An output gear 15 is connected to the ring gear 11. The engine 1 is connected to the carrier 14 via the damper 2. A first motor generator 3 is connected to the sun gear 13. An oil pump 4 is connected to the sun gear 13 and the carrier 14. In other words, a continuously variable transmission function that automatically determines the rotational speed of the output gear 15 (ring gear 11) when the rotational speed of the first motor generator 3 (sun gear 13) and the rotational speed of the engine 1 (carrier 14) are determined. Have. The output gear 15 meshes with a high-side output gear 21 fixed to the final output shaft 23.

The stepped transmission 6 includes a high-side input gear 25 rotatably supported via a bearing 27 on a motor output shaft 29 to which the second motor generator 5 is connected, and the motor output shaft 29 and the high-side input gear 25. A friction clutch 7 made of a wet multi-plate that slides in and out, a low-side input gear 24 rotatably supported via a bearing 28 on a motor output shaft 29 to which the second motor generator 5 is connected, and a motor output shaft 29 And a dog clutch 8 that engages and disconnects the low-side input gear 24. The high-side input gear 25 meshes with a high-side output gear 21 fixed to the final output shaft 23. The low-side input gear 24 meshes with the low-side output gear 22 fixed to the final output shaft 23. The stepped transmission 6 according to the first embodiment having the speed change mechanism and the speed change element is configured as described above.
When the friction clutch 7 is engaged and the dog clutch 8 is released, the "high mode" determined by the gear ratio between the high-side input gear 25 and the high-side output gear 21 is entered, and the friction clutch 7 is released and the dog clutch 8 is engaged. Then, a “low mode” determined by the gear ratio between the low-side input gear 24 and the low-side output gear 22 is set. In other words, as the shift speed, there is a two-speed transmission function having a high speed by “high mode” and a low speed by “low mode”.

  Both ends of the final output shaft 23 are supported by bearings 26 and 26, and the final output gear 30 is fixed together with the high-side output gear 21 and the low-side output gear 22. The torque transmitted to the final output gear 30 is transmitted to a pair of drive wheels 32 and 32 via a final reduction gear (not shown) and a differential device 31.

  As shown in FIG. 1, the control system of the hybrid vehicle of the first embodiment includes a first inverter 41, a second inverter 42, a battery 43, a first motor controller 44, a second motor controller 45, and an engine controller. 46, a transmission controller 47, a battery controller 48, and a hybrid controller 49.

  The first motor controller 44 controls the operating point (first torque Tm1, first rotation speed Nm1) of the first motor generator 3 according to a control command to the first inverter 41. The second motor controller 45 controls the operating point (second torque Tm2, second rotation speed Nm2) of the second motor generator 5 according to a control command for the second inverter 42.

  The engine controller 46 controls the operating point (engine torque Te, engine speed Ne) of the engine 1 by a control command to an electronically controlled throttle actuator (not shown).

  The transmission controller 47 controls the operating point (engagement / slip engagement / release) of the friction clutch 7 by a control command to a friction clutch actuator (not shown). Further, the operating point (engagement / release) of the dog clutch 8 is controlled by a control command to a dog clutch actuator (not shown).

  The battery controller 48 monitors the charge capacity (SOC) of the battery 43 and supplies SOC information, battery temperature information, and the like to the hybrid controller 49.

  The hybrid controller 49 manages the energy consumption of the entire vehicle and has a function for running the hybrid vehicle with the highest efficiency while ensuring the required driving force. The first motor controller is connected via a bidirectional communication line. 44, a second motor controller 45, an engine controller 46, a transmission controller 47, a battery controller 48, and the like. The hybrid controller 49 inputs necessary information from the accelerator opening sensor 50, the vehicle speed sensor 51, and the like. Based on the input information, a predetermined calculation process is performed, and operating point command values are output to the controllers 44, 45, 46 and 47.

  FIG. 2 is a velocity diagram in which the rotational speed (number of rotations) of each rotary element included in the drive system of the hybrid vehicle to which the control device of the first embodiment is applied is represented on the vertical axis.

  As shown in FIG. 2, the electric transmission portion includes a first motor generator 3 connected to the planetary gear device 10, the engine 1, and an output gear 15. The electric speed change portion is a continuously variable step in which the rotational speed of the output gear 15 is automatically determined when the rotational speed of the first motor generator 3 and the rotational speed of the engine 1 are determined by the two-degree-of-freedom planetary gear device 10. Has a shifting function.

  As shown in FIG. 2, the motor transmission portion includes a second motor generator 5 connected to the stepped transmission 6 via a motor output shaft 29, a friction clutch 7, a dog clutch 8, and a high-side input by a meshing pair. A gear 25, a high-side output gear 21, a low-side input gear 24 and a low-side output gear 22 formed by meshing pairs are configured. The motor speed change portion includes “high mode (high speed stage)” by engaging the friction clutch 7 (disengaging the dog clutch 8) and “low mode (low speed stage)” by engaging the dog clutch 8 (disengaging the friction clutch 7). , Has a two-speed transmission function.

  Then, in the final output shaft 23, as shown in FIG. 2, the engine direct drive torque from the electric transmission portion and the motor drive torque from the motor transmission portion are combined, and the combined drive torque transmitted to the final output gear 30 is The vehicle is transmitted to the pair of drive wheels 32 and 32 through the final reduction gear and the differential device 31 to be the vehicle speed V.

  Here, the reason why the friction clutch 7 is used in the “high mode” and the dog clutch 8 is used in the “low mode” will be described. For example, when both are friction clutches, drag loss and hydraulic pump loss occur, and the loss becomes particularly significant in the “low mode” where the transmitted torque is large. Further, for example, when both are dog clutches, there is an advantage that there is no loss, but it is necessary to completely release both the engagement side and the release side at the time of shifting, and to perform the engagement in rotation synchronization. That is, rotation synchronous control is required and torque loss occurs during the shift transition period. Therefore, in the “high mode”, the friction clutch 7 that does not require the rotation synchronization control is used, and in the “low mode”, the dog clutch 8 that suppresses the loss is used, and the shift transition period from the “high mode” to the “low mode”. The torque loss is compensated by the frictional force of the friction clutch 7.

  That is, in the motor speed change portion, during the shift transition period from the “high mode” to the “low mode”, the motor rotation speed that matches the target rotation speed from the motor torque control that matches the second motor generator 5 to the target torque. Change to control. Then, the friction clutch 7 is brought into the slip engagement state, and while performing the driving force compensation for suppressing the driving torque from being lost due to the frictional force, the rotational speed of the second motor generator 5 is increased and the input rotational speed of the dog clutch 8 (= second motor). The rotation speed of the generator 5) is synchronized with the output rotation speed (determined by the vehicle speed and gear ratio) of the dog clutch 8, and the dog clutch 8 is engaged and fastened at the rotation speed synchronization timing.

  FIG. 3 is a flowchart showing the flow of a shift control process executed by the hybrid controller 49 of the first embodiment (shift control means). Hereinafter, each step of FIG. 3 will be described.

  In step S101, necessary information such as the accelerator opening APO (or required driving force) from the accelerator opening sensor 50, the vehicle speed Vsp from the vehicle speed sensor, and the battery charge amount SOC is read, and the process proceeds to step S102.

In step S102, it is determined whether or not it is a low driving force request mode based on driver operation or traffic infrastructure information. If YES (low driving force request mode), the process proceeds to step S103, and NO (low driving force request mode). If it is not in the request mode, the process proceeds to step S109.
Here, the specific determination as to whether or not the mode is the “low driving force request mode” is made using, for example, the following method.
(a) When it is selected that the driving force requirement value may be low by the driver's operation, for example, a driver (eg, an EV switch) that means that the vehicle is driven only by the second motor generator MG2 provided in the vehicle It is determined that the required driving force may be low when the button is pressed.
For example, it is determined that the required driving force may be low when a driver (e.g., ECO switch) that is provided on the vehicle and indicates that the vehicle is traveling with low fuel consumption is pressed by the driver.
(b) When it is selected that the required driving force value may be low based on traffic infrastructure information For example, when the traffic infrastructure information is obtained through VICS (abbreviation of Vehicle Information and Communication System) etc. If the road passing to the ground is found to be a traffic jam or the like, it is determined that the required driving force may be low. “VICS” refers to a system that displays traffic information received from FM multiplex broadcasting or a transmitter on the road in graphics and characters.

In step S103, following the determination that the mode is the low driving force request mode in step S102, based on the read information, the transmission loss for each gear position is selected when “low mode” is selected or “high mode” is selected. The clutch drag loss P _CL (Lo) generated in the friction clutch 7 to be engaged and the clutch drag loss P _CL (Hi) generated in the dog clutch 8 engaged in the “low mode” when “high mode” is selected are calculated, and step S104 is performed. Proceed to A detailed method for calculating the clutch drag loss will be described later.

In step S104, following the calculation of the clutch drag loss P _CL (Lo), P _CL (Hi) in step S103, based on the read information, as the motor loss for each gear position, when “low mode” is selected, When the motor loss P _M (Lo) at the motor operating point (operating point within the range of motor maximum output, maximum speed, and maximum torque) and `` High mode '' is selected, the motor operating point (motor maximum output, The motor loss P _M (Hi) at the maximum rotation speed and the operating point within the range of the maximum torque is calculated, and the process proceeds to step S105. A detailed calculation method of the motor loss will be described later.

In step S105, following the calculation of the motor loss P _M (Lo) and P _M (Hi) in step S104, the clutch drag loss P _CL (Lo) and the motor loss P _M (Lo) when “low mode” is selected. {P _CL (Hi) + P _M (Lo)} and the sum of clutch drag loss P _CL (Hi) and motor loss P _M (Hi) when “High Mode” is selected {P _CL (Hi) + P _M (Hi)} is calculated, and then it is determined whether {P _CL (Lo) + P _M (Lo)} is greater than {P _CL (Hi) + P _M (Hi)}, and YES ({P _CL ( Lo) + P _M (Lo)}> {P _CL (Hi) + P _M (Hi)}), the process proceeds to step S106, and NO ({P _CL (Lo) + P _M (Lo)} ≦ {P _CL (Hi ) + P _M (Hi)}), the process proceeds to step S108.

In step S106, following the determination that {P _CL (Lo) + P _M (Lo)}> {P _CL (Hi) + P _M (Hi)} in step S105, the shift mode selected at the present stage Is in the “low mode”, it is assumed that the driving force in the “high mode” does not give the driver a lack of driving force, assuming that the gear shifts from the “low mode” to the “high mode”. If YES (does not give the driver a feeling of insufficient driving force), the process proceeds to step S107. If NO (provides the driver a feeling of insufficient driving force), the process proceeds to step S108. A detailed determination method for determining whether or not to give the driver a lack of driving force will be described later.

  In step S107, following the determination that the driver does not feel deficient in driving force in step S106, the gear shifts to “high mode” when in “low mode” and “high mode” when in “high mode”. ”And proceed to return.

In step S108, it is determined that {P _CL (Lo) + P _M (Lo)} ≦ {P _CL (Hi) + P _M (Hi)} in step S105, or the driving force is applied to the driver in step S106. In the case of “high mode”, the gear shifts to “low mode”, and in the case of “low mode”, “low mode” is maintained and the process proceeds to return.

  In step S109, following the determination that the mode is not the low driving force request mode in step S102, vehicle information (vehicle speed Vsp, accelerator opening APO (required driving force), battery charge amount SOC, etc.) Shift according to the shift line (normal shift), or select a shift mode with a smaller sum of clutch drag loss and motor loss, shift according to the selected shift mode (shift with minimum loss), and proceed to return.

Next, the operation will be described.
The operations of the hybrid vehicle control device of the first embodiment are as follows: “clutch drag loss calculation method”, “motor loss calculation method”, “decision method whether or not to give the driver a lack of driving force”, “ The description will be divided into “shift control action”.

[Method of calculating clutch drag loss]
It is described calculation method of the clutch drag loss P _CL at step S103 of FIG. 3.
For example, when “low mode” is selected, the friction clutch 7 is driven by a differential rotation between the drive plate and the driven plate {eg, ((number of rotations of MG2) × (gear ratio from MG2 to driven plate)) − (( Wheel rotation speed) × (gear ratio to drive plate))}. At this time, since there is a differential rotation between the drive plate and the driven plate, each plate is dragged and this is a loss.
Therefore, clutch drag loss P _CL (Lo) is
P _CL (Lo) = Nc × T = Nc × [ρ · v · N · π · R · {(Do / 2) ^2- (Di / 2) ² } / (h / 2)] × A
Nc: friction plate differential rotation T: drag torque ρ: ATF viscosity v: clutch peripheral speed (2πNc / 60)
N: Number of facing surfaces of friction plate R: Effective radius of friction plate
Do: Friction plate outer diameter
Di: Friction plate inner diameter h: Friction plate clearance A: Constant (ATF intervention coefficient, temperature correction, etc.)
It is calculated by the following formula.
Note that when the “high mode” is selected, the dog clutch 8 has a differential rotation, but in the case of the dog clutch 8, the clutch drag loss P _CL (Hi) is almost zero because the dog clutch 8 is disconnected without dragging. Become.

[Motor loss calculation method]
It shows the concept of calculating the motor loss P _M in FIG.
For example, when the number of gears of the stepped transmission 6 driven by the second motor generator 5 is two as in the first embodiment, the “low mode” in a certain traveling scene (vehicle speed Vsp, driving force Tv, etc.) The motor operating point A of the second motor generator 5 at the time of selection is the rotational speed N _Lo and the torque T _Lo , and the motor operating point B of the second motor generator 5 at the time of selecting the “high mode” is the rotational speed N _Hi and torque T _Hi . Since these operating points A and B have the same traveling scene and the same required output W,
N _Lo × T _Lo = N _Hi × T _Hi = W
It becomes. Of the motor loss at each operating point A and B, the motor loss P _M (Lo) at the motor operating point A when “low mode” is selected is 95% according to the motor efficiency map (example). So
P _M (Lo) = N _Lo × T _Lo × (1−0.95) = 0.05W
According to the motor efficiency map (example), the motor loss P _M (Hi) at the motor operating point B when “High mode” is selected is 85%.
P _M (Hi) = N _Hi × T _Hi × (1−0.85) = 0.15W
It becomes.

In this way, the motor losses P _M (Lo) and P _M (Hi) are determined based on the condition that the driving scene and the required output W are equal to each other in the “low mode” and “high mode” shift stages of the second motor generator 5. Motor operating points A and B are determined and calculated using the efficiency at each motor operating point A and B on the motor efficiency map.
Therefore, the motor losses P _M (Lo) and P _M (Hi) for estimating the power consumption in the second motor generator 5 at each shift stage can be predicted with high accuracy.

[Judgment method of whether to give the driver a lack of driving force]
FIG. 5 shows the concept of determining whether or not to give the driver a feeling of insufficient driving force.
For example, when the number of shift stages of the stepped transmission 6 is two as in the first embodiment, the operating point A when the “low mode” is selected is the vehicle speed Vsp1 and the driving force Tv _Lo , and the “high mode” The operating point B at the time of selection is the vehicle speed Vsp1 and the driving force Tv _Hi .
Thus, upon selection of "low mode" in the vehicle speed Vsp1, acceleration G _Lo by the driving force Tv _Lo is
G _Lo = (Tv _Lo -running resistance) / (vehicle weight + vehicle inertia) / gravity acceleration g ²
It becomes. Further, upon selection of "high mode" in the vehicle speed Vsp1, acceleration G _Hi by the driving force Tv _Hi is
G _Hi = (Tv _Hi -running resistance) / (vehicle weight + vehicle inertia) / gravity acceleration g ²
It becomes. And
G _Lo −G _Hi <0.2G
If the difference between acceleration G _Lo and acceleration G _Hi is 0.2G or less, even if shifting from “Low mode” to “High mode”, the driver feels that the driving force is insufficient during acceleration. I will not let you. However, the determination threshold value 0.2G of the acceleration G is assumed to vary depending on the vehicle and the target power performance.

[Shifting action]
The speed change operation will be described based on the flowchart of FIG.
First, when the vehicle is traveling and not in the low driving force request mode, the flow of steps S101 → step S102 → step S109 → return is repeated in the flowchart of FIG.
Accordingly, in step S109, a normal shift is performed in which shifting is performed according to a shift line of a predetermined shift map based on the vehicle speed Vsp, the accelerator opening APO, the battery charge amount SOC, and the like. Alternatively, the shift mode with the smaller sum of the clutch drag loss and the motor loss is selected, and the shift with the minimum loss for shifting according to the selected shift mode is performed.

On the other hand, when the vehicle is traveling and in the low driving force request mode, the process proceeds from step S101 to step S102 to step S103 to step S104 to step S105 in the flowchart of FIG. If {P _CL (Lo) + P _M (Lo)} ≦ {P _CL (Hi) + P _M (Hi)} is determined in step S105, the process proceeds from step S105 to step S108, and is selected at the time of determination. If the shift mode being set is “low mode”, “low mode” is maintained, and if the shift mode selected at the time of determination is “high mode”, shift to “low mode” is performed.

If it is determined in step S105 that {P _CL (Lo) + P _M (Lo)}> {P _CL (Hi) + P _M (Hi)}, the process proceeds from step S105 to step S106, and in step S106, When the “low mode” is selected at the current stage, it is determined whether or not the driver is not given a feeling of insufficient driving force when shifting to the “high mode”. Then, when giving a feeling of insufficient driving force, the process proceeds from step S106 to step S108, and the selection of “low mode” is maintained regardless of the loss sum condition in step S105. If it is determined in step S106 that there is no lack of driving force, the process proceeds from step S106 to step S107, and the speed is changed from “low mode” to “high mode” according to the loss sum condition in step S105. When “high mode” is selected at this stage, the process proceeds from step S106 to step S107, and the selection of “high mode” is maintained.

As described above, in the shift control of the first embodiment, the clutch drag loss P _CL (Lo), P _CL (Hi) of the stepped transmission 6 at each of the “low mode” and “high mode” shift stages is predicted. (Step S103), motor losses P _M (Lo) and P _M (Hi) of the second motor generator 5 at each gear position are predicted (Step S104), and the predicted clutch drag loss P _CL (Lo) and motor loss P are calculated. _Of the sum of _M (Lo) and the predicted clutch drag loss P _CL (Hi) and motor loss P _M (Hi), the smallest shift speed is selected (step S105), and the selected shift speed is selected. When is different from the current gear position, the gear is shifted to the selected gear position (step S107, step S108).
Therefore, in the hybrid vehicle, the drive energy consumption amount that combines the fuel consumption amount of the engine 1 and the power consumption amount of the second motor generator 5 can be reduced.

Furthermore, in the shift control of the first embodiment, the sum of the predicted clutch drag loss P _CL (Lo) and the motor loss P _M (Lo) and the predicted clutch drag loss P _CL (Hi) and the motor loss P _M (Hi) of the sum, (step S105) while determining the smallest gear stage, difference in the acceleration G _Hi by the driving force Tv _Hi of the acceleration G _Lo by the driving force Tv _Lo "low mode", "high mode" (G _Lo (−G _Hi ) is determined to be within a predetermined value (for example, 0.2G) (step S106). If (G _Lo −G _Hi )> 0.2G, selection of the gear position that minimizes the loss sum is prohibited. (Step S106 → Step S108) If (G _Lo −G _Hi ) ≦ 0.2G, selection of the gear position that minimizes the loss sum is performed (Step S106 → Step S107).
Therefore, it is possible to reduce the amount of driving energy consumed while suppressing the driver from feeling deficient in driving force with the shift.

Next, the effect will be described.
In the hybrid vehicle control device of the first embodiment, the following effects can be obtained.

(1) A drive motor (second motor generator 5), a stepped transmission 6, and drive wheels 32, 32 are provided in order from the upstream side of the drive system, and the stepped transmission 6 includes a transmission mechanism. Control of a hybrid vehicle having a speed change element (friction clutch 7 and dog clutch 8), and provided with a speed change control means for changing to a selected gear stage by switching control of engagement / release of the speed change element when a speed change condition is satisfied. In the apparatus, the shift control means (FIG. 3) predicts clutch drag loss P _CL (Lo), P _CL (Hi) of the stepped transmission 6 at each of the “low mode” and “high mode” shift stages. (Step S103), motor losses P _M (Lo) and P _M (Hi) of the second motor generator 5 at each gear position are predicted (Step S104), and the predicted clutch drag loss P _CL (Lo) and motor loss P are calculated. _The clutch drag loss P estimated as the sum of _M (Lo) _From the sum of _CL (Hi) and motor loss P _M (Hi), the gear position that is basically the smallest is selected (step S105), and when the selected gear speed is different from the current gear speed, the gear is shifted to the selected gear speed. (Step S107, Step S108).
For this reason, at the time of traveling, the consumption amount of drive energy can be reduced by performing the shift control that selects the shift stage in consideration of the transmission loss and the motor loss.

(2) The shift control means (FIG. 3) calculates the sum of the predicted clutch drag loss P _CL (Lo) and the motor loss P _M (Lo) and the predicted clutch drag loss P _CL (Hi) and the motor loss P _M ( of the sum of Hi), (step S105), the difference between the acceleration G _Hi by the driving force Tv _Hi of the acceleration G _Lo by the driving force Tv _Lo "low mode", "high mode" while determining the gear position of smallest It is determined whether or not (G _Lo −G _Hi ) is within a predetermined value (for example, 0.2 G) (step S106). If (G _Lo −G _Hi )> 0.2G, selection of the gear position that minimizes the loss sum is selected. Is prohibited (step S106 → step S108), and if (G _Lo −G _Hi ) ≦ 0.2G, the gear position with the minimum loss sum is selected (step S106 → step S107).
For this reason, it is possible to reduce the amount of driving energy consumed while suppressing the driver from feeling deficient in driving force with the shift.

(3) The shift control means (FIG. 3) sets the motor losses P _M (Lo) and P _M (Hi) to “low mode” and “high mode” under the condition that the driving scene and the required output W are equal. The motor operating points A and B of the second motor generator 5 at the gear position are determined and calculated using the efficiency at each motor operating point A and B on the motor efficiency map (step S104).
Therefore, the motor losses P _M (Lo) and P _M (Hi) for estimating the power consumption in the second motor generator 5 at each shift stage can be predicted with high accuracy.

  The second embodiment is an example in which a transmission having a third speed is used as a stepped transmission and a friction clutch using three wet multi-plates is used as a transmission element.

First, the configuration will be described.
FIG. 6 is an overall system diagram illustrating a configuration of a drive system and a control system of a hybrid vehicle (an example of an electric vehicle) to which the control device of the second embodiment is applied. The drive system configuration and control system configuration will be described below with reference to FIG.

  As shown in FIG. 6, the drive system of the hybrid vehicle of the second embodiment includes an engine 1, a damper 2, a first motor generator 3, an oil pump 4, a second motor generator 5 (drive motor), A step transmission 6 ′, a high clutch 7 ′ (transmission element), a middle clutch 33 (transmission element), a low clutch 8 ′ (transmission element), and the planetary gear device 10 are provided.

The stepped transmission 6 ′ includes a high-side input gear 25 that is rotatably supported by a motor output shaft 29 to which the second motor generator 5 is connected via a bearing 27, a motor output shaft 29, and a high-side input gear. A high clutch 7 ′ using a wet multi-plate that slides and connects 25, a middle input gear 34 that is rotatably supported via a bearing 36 on a motor output shaft 29 to which the second motor generator 5 is connected, and a motor output shaft 29 and the middle side input gear 34 that slides and connects the middle side input gear 34 and a low side input gear 24 that is rotatably supported via a bearing 28 on a motor output shaft 29 to which the second motor generator 5 is connected. And a low clutch 8 ′ that engages and disconnects the motor output shaft 29 and the low-side input gear 24. The high-side input gear 25 meshes with a high-side output gear 21 fixed to the final output shaft 23. The middle input gear 34 meshes with a middle output gear 35 fixed to the final output shaft 23. The low-side input gear 24 meshes with the low-side output gear 22 fixed to the final output shaft 23. The stepped transmission 6 ′ according to the second embodiment having the speed change mechanism and the speed change element is configured as described above.
When the high clutch 7 ′ is engaged and the middle clutch 33 and the low clutch 8 ′ are released, the “high mode” determined by the gear ratio between the high side input gear 25 and the high side output gear 21 is set. When the middle clutch 33 is engaged and the high clutch 7 ′ and the low clutch 8 ′ are disengaged, a “middle mode” determined by the gear ratio between the middle input gear 34 and the middle output gear 35 is set. When the low clutch 8 ′ is engaged and the high clutch 7 ′ and the middle clutch 33 are released, the “low mode” determined by the gear ratio between the low side input gear 24 and the low side output gear 22 is set. That is, as the shift gear, a three-speed transmission function having a high speed by “high mode”, a medium speed by “middle mode”, and a low speed by “low mode” is provided.

  As shown in FIG. 6, the control system of the hybrid vehicle of the second embodiment includes a first inverter 41, a second inverter 42, a battery 43, a first motor controller 44, a second motor controller 45, and an engine controller. 46, a transmission controller 47 ′, a battery controller 48, and a hybrid controller 49.

The transmission controller 47 'operates the operating point of the high clutch 7' (engaged / released), the operating point of the middle clutch 33 (engaged / released), and the operation of the low clutch 8 'by a control command to a friction clutch actuator (not shown). Control the point (fastening / opening).
Other configurations are the same as those of the first embodiment shown in FIG.

  FIG. 7 is a velocity diagram in which the rotation speed (number of rotations) of each rotation element included in the drive system of the hybrid vehicle to which the control device of the second embodiment is applied is represented on the vertical axis.

  As shown in FIG. 7, the electric transmission portion includes a first motor generator 3 connected to the planetary gear device 10, the engine 1, and an output gear 15. The electric speed change portion is a continuously variable step in which the rotational speed of the output gear 15 is automatically determined when the rotational speed of the first motor generator 3 and the rotational speed of the engine 1 are determined by the two-degree-of-freedom planetary gear device 10. Has a shifting function.

  As shown in FIG. 7, the motor transmission portion includes the second motor generator 5 connected to the stepped transmission 6 ′ via the motor output shaft 29, the high clutch 7 ′, the middle clutch 33, and the low clutch 8. ', The high-side input gear 25 and the high-side output gear 21 by the meshing pair, the middle-side input gear 34 and the middle-side output gear 35 by the meshing pair, and the low-side input gear 24 and the low-side output gear 22 by the meshing pair. It is comprised by. The motor speed change portion includes “high mode (high speed)” by engaging the high clutch 7 ′, “middle mode (medium speed)” by engaging the middle clutch 33, and “low mode” by engaging the low clutch 8 ′. It has a three-speed shift function for switching between “mode (low speed)”.

  Then, in the final output shaft 23, as shown in FIG. 7, the engine direct drive torque from the electric transmission portion and the motor drive torque from the motor transmission portion are combined, and the combined drive torque transmitted to the final output gear 30 is The vehicle is transmitted to the pair of drive wheels 32 and 32 through the final reduction gear and the differential device 31 to be the vehicle speed V.

  FIG. 8 is a flowchart showing the flow of shift control processing executed by the hybrid controller 49 of the second embodiment (shift control means). Hereinafter, each step of FIG. 8 will be described. Steps S201 and S202 are the same processes as steps S101 and S102 in the flowchart of FIG.

In step S203, following the determination that the mode is the low driving force request mode in step S202, based on the read information, as the transmission loss for each shift stage, when “low mode” is selected, the high clutch 7 ′ Clutch drag loss P _CL (Lo) generated in the middle clutch 33 and clutch drag loss P _CL (Mid) generated in the high clutch 7 ′ and the low clutch 8 ′ when “middle mode” is selected, and selection of “high mode” At this time, the clutch drag loss P _CL (Hi) generated in the middle clutch 33 and the low clutch 8 ′ is calculated, and the process proceeds to step S204. The method for calculating the clutch drag loss is the same as that in the first embodiment.

In step S204, following the calculation of clutch drag loss P _CL (Lo), P _CL (Mid), and P _CL (Hi) in step S203, based on the read information, the motor loss for each gear position is calculated as “low When `` Mode '' is selected, the motor loss P <sub>M</sub> (Lo) at the motor operating point (operating point within the range of maximum motor output, maximum speed, and maximum torque) and when `` Middle Mode '' is selected, the motor operating point Motor loss P _M (Mid) at (maximum motor output, maximum rotation speed, operating point within the range of maximum torque) and motor operation point (maximum motor output, maximum rotation speed) when `` High mode '' is selected The motor loss P _M (Hi) at the operating point within the range of the maximum torque is calculated, and the process proceeds to step S205. The motor loss calculation method is the same as in the first embodiment.

In step S205, following the calculation of the motor losses P _M (Lo), P _M (Mid), and P _M (Hi) in step S204, the clutch drag loss P _CL (Lo) and the motor when “low mode” is selected. Sum of loss P _M (Lo) {P _CL (Lo) + P _M (Lo)} and sum of clutch drag loss P _CL (Mid) and motor loss P _M (Mid) when “middle mode” is selected {P _CL (Mid) + P _M (Mid)} and the sum of clutch drag loss P _CL (Hi) and motor loss P _M (Hi) when “high mode” is selected {P _CL (Hi) + P _M (Hi)} Then, {P _CL (Lo) + P _M (Lo)}, {P _CL (Mid) + P _M (Mid)}, and {P _CL (Hi) + P _M (Hi)} If the loss when selecting “High Mode” is minimum, the process proceeds to Step S206. If the loss when selecting “Middle Mode” is minimum, the process proceeds to Step S208. When “Low Mode” is selected. When the loss of is minimum, the process proceeds to step S210.

  In step S206, following the determination that the Hi loss is the minimum in step S205, when the shift mode currently selected is “middle mode”, the gear shifts from “middle mode” to “high mode”. Assuming that the driving force in the “high mode” does not give the driver a feeling of lack of driving force, if YES (does not give the driver a feeling of lack of driving force), step S207 If NO (giving the driver a lack of driving force), the process proceeds to step S208. A detailed determination method for determining whether or not to give the driver a lack of driving force will be described later.

  In step S207, following the determination that the driver does not feel deficient in driving force in step S206, the gear shifts to “high mode” in “middle mode” and “high mode” in “high mode”. ”And proceed to return.

  In step S208, following the determination in step S205 that the Mid loss is the minimum or the determination in step S206 that the driver feels deficient in driving force, the shift mode currently selected is “ Assuming that the gear shifts from “low mode” to “middle mode” when in “low mode”, it is determined whether the driving force in “middle mode” does not give the driver a lack of driving force. If YES (does not give the driver a feeling of insufficient driving force), the process proceeds to step S209. If NO (provides the driver a feeling of insufficient driving force), the process proceeds to step S210. A detailed determination method for determining whether or not to give the driver a lack of driving force will be described later.

  In step S209, following the determination that the driver does not feel deficient in driving force in step S208, the gear shifts to “middle mode” in “low mode”, and “middle mode” in “middle mode”. ”And proceed to return.

  In Step S210, following the determination that the Lo loss is the minimum in Step S205, or the determination that the driver feels insufficient driving power in Step S208, the “Low Mode” when in the “Middle Mode” When in the “low mode”, the “low mode” is maintained and the process proceeds to return.

  In step S211, following the determination that the low driving force request mode is not in step S202, vehicle information (vehicle speed Vsp, accelerator opening APO (required driving force), battery charge amount SOC, etc.) Shift according to the shift line (normal shift), or select a shift mode with a smaller sum of clutch drag loss and motor loss, shift according to the selected shift mode (shift with minimum loss), and proceed to return.

Next, the operation will be described.
The operation of the hybrid vehicle control apparatus according to the second embodiment will be described by dividing it into “a method for determining whether or not to give the driver a lack of driving force” and “a shift control operation”.

[Judgment method of whether to give the driver a lack of driving force]
FIG. 9 shows the concept of determining whether or not to give the driver a feeling of insufficient driving force.
For example, when the number of shift stages of the stepped transmission 6 ′ is 3 as in the second embodiment, the operating point A when the “low mode” is selected is the vehicle speed Vsp1, the driving force Tv _Lo , and the “middle mode”. The operation point B at the time of selection is the vehicle speed Vsp1 and the driving force Tv _Mid , and the operation point B ′ at the time of selecting the “middle mode” is the vehicle speed Vsp2 and the driving force Tv _{Mid ′} and at the time of the selection of the “high mode” The operating point C is the vehicle speed Vsp2 and the driving force Tv _Hi .

Thus, upon selection of "low mode" in the vehicle speed Vsp1, acceleration G _Lo by the driving force Tv _Lo is
G _Lo = (Tv _Lo -running resistance) / (vehicle weight + vehicle inertia) / gravity acceleration g ²
It becomes. Further, upon selection of "middle mode" in the vehicle speed Vsp1, acceleration G _Mid by the driving force Tv _Mid is
G _Mid = (Tv _Mid -running resistance) / (vehicle weight + vehicle inertia) / gravity acceleration g ²
It becomes. Therefore, when the difference between them is 0.2G, that is,
G _Lo −G _Mid <0.2G
When the above holds, it is assumed that the driver does not feel a large lack of driving force during acceleration even when shifting from the “low mode” to the “middle mode”. However, the determination threshold value 0.2G of the acceleration G is assumed to vary depending on the vehicle and the target power performance.

Further, upon selection of "middle mode" in the vehicle speed Vsp2, _{'acceleration} G _{Mid by'} driving force Tv _Mid is
G _{Mid '} = (Tv _Mid'- running resistance) / (vehicle weight + vehicle inertia) / gravity acceleration g ²
It becomes. Further, upon selection of "high mode" in the vehicle speed Vsp2, acceleration G _Hi by the driving force Tv _Hi is
G _Hi = (Tv _Hi -running resistance) / (vehicle weight + vehicle inertia) / gravity acceleration g ²
It becomes. Therefore, when the difference between them is 0.2G, that is,
G _{Mid '} −G _Hi <0.2G
Suppose that the driver does not feel a large lack of driving force during acceleration even when shifting from “middle mode” to “high mode”. However, the determination threshold value 0.2G of the acceleration G is assumed to vary depending on the vehicle and the target power performance.

[Shifting action]
The speed change operation will be described based on the flowchart of FIG.
First, when the vehicle is traveling and not in the low driving force request mode, the flow of steps S201 → step S202 → step S211 → return is repeated in the flowchart of FIG.
Therefore, in step S211, a normal shift that shifts according to a shift line of a predetermined shift map is performed based on the vehicle speed Vsp, the accelerator opening APO, the battery charge amount SOC, and the like. Alternatively, a shift mode with a small sum of clutch drag loss and motor loss is selected from “high mode”, “middle mode”, and “low mode”, and a shift with a minimum loss is performed according to the selected shift mode.

  On the other hand, when the vehicle is traveling and in the low driving force request mode, the process proceeds from step S201 to step S202 to step S203 to step S204 to step S205 in the flowchart of FIG. If it is determined in step S205 that the Lo loss is minimum, the process proceeds from step S205 to step S210. If the speed change mode selected at the time of determination is “low mode”, “low mode” is maintained and the determination is made. If the currently selected shift mode is “middle mode”, the shift to “low mode” is performed.

  If it is determined in step S205 that the Mid loss is minimum, the process proceeds from step S205 to step S208. When “low mode” is currently selected in step S208, the gear shifts to “middle mode”. It is determined whether or not the driver is given a lack of driving force. Then, when giving a feeling of insufficient driving force, the process proceeds from step S208 to step S210, and the selection of “low mode” is maintained regardless of the determination of the minimum Mid loss in step S205. If it is determined in step S208 that the driving force is not insufficient, the process proceeds from step S208 to step S209, and the speed is changed from “low mode” to “middle mode” according to the minimum Mid loss determination in step S205. . If “middle mode” is selected at this stage, the process proceeds from step S208 to step S209, and the selection of “middle mode” is maintained.

  If it is determined in step S205 that the Hi loss is minimum, the process proceeds from step S205 to step S206, and when "middle mode" is currently selected in step S206, the gear shifts to "high mode". It is determined whether or not the driver is given a lack of driving force. Then, when giving a feeling of insufficient driving force, the process proceeds from step S206 to step S208, and the selection of “middle mode” is maintained regardless of the Hi loss minimum determination in step S205. If it is determined in step S206 that the driving force is not insufficient, the process proceeds from step S206 to step S207, and the speed is changed from “middle mode” to “high mode” according to the Hi loss minimum determination in step S205. . If “high mode” is selected at this stage, the process proceeds from step S206 to step S207, and the selection of “high mode” is maintained.

As described above, in the shift control of the second embodiment, the clutch drag loss P _CL (Lo), P _CL (Mid), P _CL of the stepped transmission 6 at each of the “low mode” and “high mode” shift stages. (Hi) is predicted (step S203), and motor losses P _M (Lo), P _M (Mid), and P _M (Hi) of the second motor generator 5 at each gear position are predicted (step S204). The sum of clutch drag loss P _CL (Lo) and motor loss P _M (Lo), the sum of predicted clutch drag loss P _CL (Mid) and motor loss P _M (Mid), and the predicted clutch drag loss P _CL ( Hi) and the motor loss P _M (Hi) are summed up so that the smallest shift speed is selected (step S205), and when the selected shift speed is different from the current shift speed, the speed is changed to the selected speed. (Step S207, Step S209, Step S210).
Therefore, in the hybrid vehicle, the drive energy consumption amount that combines the fuel consumption amount of the engine 1 and the power consumption amount of the second motor generator 5 can be reduced.

Further, in the shift control of the second embodiment, the sum of the predicted clutch drag loss P _CL (Lo) and the motor loss P _M (Lo), the predicted clutch drag loss P _CL (Mid), and the motor loss P _M (Mid) , And the estimated sum of the clutch drag loss P _CL (Hi) and the motor loss P _M (Hi), the minimum gear position is determined (step S205), and the “low mode” driving force Tv _{Lo is determined.} the difference of the acceleration G _Mid by the driving force Tv _Mid of the acceleration G _Lo "middle mode" by (G _Lo -G _Mid) is to determine whether within a predetermined value (e.g., 0.2 G) (step S208), (G _Lo If “−G _Mid ”> 0.2G, the selection of “middle mode” is prohibited (step S208 → step S210). If (G _Lo −G _Mid ) ≦ 0.2G, the selection of “middle mode” is executed. (Step S208 → Step S209). Further, the difference between the acceleration G _Hi by the driving force Tv _Hi "high mode" (G _{Mid '-G Hi)} is a predetermined _value' acceleration G _Mid by _'driving force Tv _Mid of the "middle mode" (e.g., 0.2 G) If (G _{Mid '} -G _Hi )> 0.2G, the selection of "high mode" is prohibited (Step S206 → Step S208), and (G _Mid' -G _Hi ) If ≦ 0.2G, the selection of “high mode” is executed (step S206 → step S207).
Therefore, it is possible to reduce the amount of driving energy consumed while suppressing the driver from feeling deficient in driving force with the shift.

  As mentioned above, although the control apparatus of the electric vehicle of this invention has been demonstrated based on Example 1 and Example 2, it is not restricted to these Examples about a concrete structure, Each claim of a claim Design changes and additions are permitted without departing from the spirit of the invention according to the paragraph.

  In the first embodiment, an example in which the friction clutch 7 (wet clutch) and the dog clutch 8 are used as the speed change element of the stepped transmission 6 has been described. In the second embodiment, an example in which a high clutch 7 ′, a middle clutch 33, and a low clutch 8 ′ using a wet clutch, which is a semi-engageable friction engagement device, is used as a transmission element of the stepped transmission 6 ′. . However, examples using a dog brake as a meshing engagement device and a brake as a semi-engageable friction engagement device are also included. Further, the stepped transmissions 6 and 6 ′ are not limited to the transmission structures shown in the first and second embodiments, and may be other transmission mechanisms such as planetary gears that perform transmission using a clutch and a brake.

  In the first embodiment, an example is shown in which the clutch drag loss is calculated as the transmission loss. However, the transmission loss may include an example of including gear loss, bearing loss, etc. in addition to clutch drag loss.

  In the first and second embodiments, the control device is applied to a hybrid vehicle equipped with an engine, a first motor generator, and a second motor generator. However, other types of hybrid vehicles, electric vehicles, fuel cell vehicles, etc. The control device of the present invention can also be applied to this electric vehicle. For example, as shown in FIG. 10, the present invention can also be applied to an electric vehicle having a second motor generator 5, a stepped transmission 6, and left and right drive wheels 32, 32 in the drive system. In short, any electric vehicle having a drive motor, a stepped transmission, and drive wheels can be applied to the drive system.

DESCRIPTION OF SYMBOLS 1 Engine 2 Damper 3 1st motor generator 4 Oil pump 5 2nd motor generator (drive motor)
6,6 'transmission (stepped transmission)
7 Friction clutch (transmission element)
7 'High clutch (transmission element)
33 Middle clutch (transmission element)
8 Dog clutch (transmission element)
8 'Low clutch (transmission element)
DESCRIPTION OF SYMBOLS 10 Planetary gear apparatus 32 Drive wheel 41 1st inverter 42 2nd inverter 43 Battery 44 1st motor controller 45 2nd motor controller 46 Engine controller 47, 47 'Transmission controller 48 Battery controller 49 Hybrid controller 49' Integrated controller 50 Accelerator opening degree Sensor 51 Vehicle speed sensor

Claims (3)

In order from the upstream side of the drive system, a drive motor, a stepped transmission, and drive wheels are provided,
The stepped transmission includes a speed change mechanism and a speed change element, and includes a speed change control means for changing to a speed selected by a change control of engagement / release of the speed change element when a speed change condition is satisfied. In the control device of
The shift control means predicts a transmission loss of the stepped transmission at each shift stage, predicts a motor loss of the drive motor at each shift stage, and the sum of the predicted transmission loss and motor loss is minimized. A control device for an electric vehicle characterized by selecting a shift speed to be changed and shifting to the selected shift speed when the selected shift speed is different from the current shift speed. In the control device of the electric vehicle according to claim 1,
The shift control means determines the shift speed at which the sum of the predicted transmission loss and motor loss is minimized, and the difference between the predicted drive force value at the current shift speed and the predicted drive power value at the shift speed is Judgment is made whether the difference is within a predetermined value, and if the predicted driving force difference exceeds the predetermined value, the selection of the gear position that minimizes the loss sum is prohibited. If the predicted driving force difference is within the predetermined value, the loss sum A control device for an electric vehicle, characterized in that selection of a gear position that minimizes is performed. In the control apparatus for the electric vehicle according to claim 1 or 2,
The shift control means determines the motor operating point of the drive motor at each shift stage on the condition that the required output is equal to the travel scene, and uses the efficiency at each motor operating point on the motor efficiency characteristics. A control device for an electric vehicle, characterized by:

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