JP5893435B2 - Automatic transmission control device for electric vehicles - Google Patents

Description

The invention has an automatic transmission for transmitting to the wheels by shifting the driving of the motor, the form comprising only the motor as the drive source or motor and the automatic transmission control equipment of an electric vehicle of a hybrid type including an engine, about the.

  While electric vehicles are generally superior in terms of low pollution and energy saving compared to engine vehicles, the short cruising range of one charge is a major issue. One way to improve the one-charge cruising range is to combine an automatic transmission with a motor, and one cruising range can be achieved by traveling at a gear ratio that makes the drive unit highly efficient in accordance with the driving conditions. The distance can be improved. Patent Document 1 discloses a known technique for calculating an appropriate gear ratio according to a traveling condition and shifting the gear ratio to travel.

  In Patent Document 1, the motor / inverter efficiency at each gear is calculated using the motor rotation speed, motor torque command value, and motor / inverter efficiency map obtained from the vehicle speed. Calculate the motor speed at which the calculated motor / inverter efficiency is maximum, and control the gear stage of the automatic transmission using the gear ratio at the calculated motor speed as the gear ratio setting value of the automatic transmission. Drive at the gear ratio that provides the best efficiency.

JP-A-10-248113

  The efficiency of the entire drive unit including the motor, the inverter, and the variable gear ratio can be divided into three: inverter efficiency, motor efficiency, and transmission (reduction gear) efficiency. In the technique described in Patent Document 1, only the inverter efficiency and the motor efficiency among the three efficiencies are considered, and the transmission efficiency is not considered. Since the transmission efficiency changes according to the shift speed, the method of Patent Document 1 cannot always select the shift speed at which the efficiency of the entire drive unit is the best.

  In this invention, in addition to the inverter efficiency and the motor efficiency, the transmission efficiency that changes according to the shift speed is also taken into consideration, so that the gear ratio and the shift speed at which the efficiency of the entire drive unit is optimal can be estimated with high accuracy. An object of the present invention is to provide an automatic transmission control device for an electric vehicle that is capable of improving one cruising range by running using the best gear ratio and gear stage estimated with high accuracy. To do.

In the automatic transmission control device 1 to the prerequisite configuration electric motor vehicle, a motor 3, an inverter 5 for applying a driving electric power to the motor 3, an automatic transmission 4 to convey the wheel to shift the rotation of the motor 3 A device for controlling the automatic transmission 4 in an electric vehicle EV, HV of a type equipped with only the motor 3 as a travel drive source or a hybrid type electric vehicle EV, HV comprising the motor 3 and the engine E. There,
Drive unit efficiency calculation means 21 for calculating the drive unit efficiency, which is the efficiency of the drive unit 2 at each gear ratio or gear stage of the automatic transmission 4, and the gear ratio or the drive unit efficiency at which the calculated drive unit efficiency is maximum. An optimum gear ratio / shift speed determining means 22 for determining the shift speed, and a shift command output means 23 for setting the speed ratio or shift speed determined to be the highest in the automatic transmission;
The drive unit efficiency calculating means 21 calculates inverter efficiency, motor efficiency, and transmission efficiency, and calculates drive unit efficiency using these three efficiencies.

The drive unit efficiency, which is the overall efficiency of the drive unit 2, can be expressed by the product of three efficiencies: inverter efficiency, motor efficiency, and transmission efficiency. Input power from the battery 9 becomes power for driving the wheels via the automatic transmission 4 via the inverter 5 and the motor 3. In this transmission path, inverter loss, motor loss, and transmission loss occur. These losses vary depending on the gear ratio and the gear position. Therefore, the drive unit efficiency when traveling at each gear ratio and gear stage is calculated and compared, and the gear ratio and gear stage that provides the best drive unit efficiency are selected as travel gears, and the vehicle travels with a shift. This makes it possible to travel with the highest drive unit efficiency, and to improve the one-charge cruising range.
The drive unit efficiency is not limited to the product obtained by multiplying the inverter efficiency, the motor efficiency, and the transmission efficiency as they are, and an appropriate process such as weighting or correction is performed for each efficiency. The drive unit efficiency may be calculated.

For the calculation of drive unit efficiency,
・ Inverter efficiency, motor efficiency, and transmission efficiency are individually expressed by theoretical or empirical formulas from the motor torque command value, motor speed, and oil temperature, and each efficiency is calculated based on these formulas and accumulated. How to determine drive unit efficiency,
・ Inverter efficiency, motor efficiency, and transmission efficiency from motor torque command value, motor speed, and oil temperature are individually expressed in theoretical maps, experimental formulas, and efficiency maps derived from experimental results. Each efficiency map is based on each efficiency map. To calculate drive unit efficiency by calculating and stacking,
・ A motor torque command value, motor rotation speed, oil temperature, inverter efficiency, motor efficiency, and transmission efficiency are partly or entirely represented by theoretical, experimental, and efficiency maps derived from experimental results. How to determine drive unit efficiency,
Any method may be used.

The automatic transmission 4 may be of a type having a plurality of shift speeds, or of a type capable of continuously selecting an arbitrary gear ratio within a certain range.
In the case of the automatic transmission 4 having a plurality of shift speeds, the drive unit efficiency calculating means 21 calculates the drive unit efficiency at each shift speed, and the optimum gear ratio / shift speed determining means 22 has a drive unit efficiency. The shift stage that is the highest is determined, and the shift command output means 23 sets the shift stage that is determined to be the highest in the automatic transmission 4.

When the automatic transmission 4 is in a format that can continuously select an arbitrary gear ratio within a certain range, for example, in the case of a continuously variable transmission, the gear ratio that maximizes the drive unit efficiency is calculated. However, this gear ratio may be set to the gear ratio of the transmission.
That is, the drive unit efficiency calculating means 21 calculates the drive unit efficiency at a plurality of selectable gear ratios, and the optimum speed ratio / speed stage determining means 22 compares the calculated drive unit efficiencies. It is also possible to determine the maximum gear ratio, and the shift command output means 23 may set the gear ratio determined to be the highest in the automatic transmission 4.
The above-mentioned “calculate the drive unit efficiency at a plurality of selectable gear ratios” means to calculate the drive unit efficiency at a plurality of gear ratios with arbitrarily determined intervals in the case of a continuous shift. In addition, “a certain range” in the above “select an arbitrary speed ratio continuously within a certain range” means “a physically selectable range”.

  In this case, the gear ratio can be selected infinitely finely, and the drive unit efficiency at all the selected gear ratios may be obtained. However, if the drive unit efficiency for each gear ratio selected infinitely finely is calculated, an enormous amount of time is required. In the worst case, computation may be impossible. In order to avoid such a phenomenon and to prevent optimal gear selection failure and drive feeling deterioration due to calculation delay, the gear ratio to be calculated is calculated at regular intervals (for example, the selectable gear ratio range is divided into ten). Then, the gear ratio that provides the best drive unit efficiency may be estimated from the drive unit efficiency at the gear ratio at regular intervals.

Specifically, the drive unit efficiency is the best from the drive unit efficiency at a fixed gear ratio (temporary maximum efficiency point), the drive unit efficiency η _max , η _max-1 , η before and after that point. _{max + 1} and gear ratios i _max , i _max-1 , i _{max + 1} are selected and the best drive unit efficiency point is estimated from the three points using a quadratic function, and the number of points is increased to a higher order function Can be used to estimate the best drive unit efficiency point, and again to divide every predetermined interval within the gear ratio range extracted at the three points and repeatedly estimate the best drive unit efficiency point. A method may be used.

More specifically, in the automatic transmission control device 1 for an electric vehicle according to the first aspect of the present invention, in the premise configuration, the automatic transmission 4 continuously selects an arbitrary transmission ratio within a certain range. The drive unit efficiency calculating means 21 calculates the drive unit efficiency at a plurality of selectable gear ratios, and the optimum gear ratio / speed stage determining means 22 is a plurality of drives for which the calculation has been performed. determines the speed ratio to be the best by comparing unit efficiency, the shift command output unit 23 is used to set up and become the determined gear ratio to the automatic transmission 4, the front SL drive unit efficiency calculating means 21 Calculates the gear ratio to be calculated at regular intervals, and the optimum gear ratio / shift speed determination means 22 determines the drive unit efficiency from the drive unit efficiency at the calculated gear ratio at regular intervals. High become speed ratio estimate determining a gear ratio to be highest, and the estimated gear ratio.

  In addition, the optimum speed ratio / speed stage determination means 23 obtains a provisional maximum efficiency point and a plurality of points before and after the speed ratio at the fixed intervals, and obtains the highest An optimal transmission ratio estimation method for estimating a transmission ratio that achieves the best drive unit efficiency using a secondary function may be used.

  The optimum gear ratio / speed stage determining means 22 obtains a provisional maximum efficiency point and one point before and after that at the gear ratio at regular intervals, and uses the quadratic function from the information of the three points to determine the best drive unit. An optimum transmission ratio estimation method for estimating a transmission ratio that achieves efficiency may be used.

  The optimum speed ratio / speed stage determining means 23 obtains a provisional maximum efficiency point and a point before and after it at the speed ratio at regular intervals, and compares the efficiency at one point before and after. And determining that the speed ratio that achieves the best drive unit efficiency is between the speed ratio at the provisional maximum efficiency point and the determined speed ratio. An optimum speed ratio estimation method may be used in which the range of the ratio and the determined speed ratio is further divided at regular intervals and the best drive unit efficiency is repeatedly calculated.

The above action is an action at the time of power running in which the power of the motor 3 is transmitted to the wheels via the drive system, but is not limited to at the time of power running but also at the time of power running at the time of regeneration in which the motor 3 absorbs the kinetic energy of the wheels via the drive system. Has the same effect. That is, it is possible to recover a larger amount of electric power by shifting to a gear ratio and gear position that provides the best regenerative efficiency of the entire drive unit 2, and to improve one charge cruising distance.
In the case of power running, the motor torque command value can be changed according to the accelerator pedal operation amount. Therefore, it is possible to calculate the efficiency by using the motor torque command value and the motor rotation speed obtained from the vehicle speed and the gear position or the gear ratio within the conditions satisfying the vehicle torque required by the driver as the variable parameters. On the other hand, in the case of regeneration, unlike the case of powering, the SOC of the battery also affects the motor torque command value is not determined only by the brake pedal operation amount. Therefore, regenerative motor torque command value calculation means may be provided, and the efficiency may be calculated with the regenerative motor torque command value calculated by the regenerative motor torque command value calculation means unchanged and only the motor rotation number as a variable parameter. Incidentally, the vehicle torque is the torque transmitted to the wheels, that is, the torque after the output torque of the traveling motor is amplified by the speed reducer.

Automatic shift control apparatus 1 for an electric vehicle of the second invention in the inventions are Oite the premise construction, the drive unit efficiency calculating means 21, at the time of regeneration to a fixed value regenerative motor torque command value, gear ratio or The only parameter that is changed according to the gear position is the motor speed .

Instantaneous fuel consumption and cruising distance estimator for an electric vehicle of the present invention 14, the assumed automated shift control device of the configuration 1, instantaneous fuel consumption and cruising distance using the highest drive unit efficiency calculated by the automatic transmission control device 1 And instantaneous fuel consumption / cruising distance estimating means 14 for estimating.
Since the drive unit efficiency can be estimated with high accuracy as described above, the effect of improving the instantaneous fuel consumption meter mounted on many automobiles and the display accuracy of the estimated cruising distance by the instantaneous fuel consumption / cruising distance estimating device 14 of the present invention. Can be expected.

Electric vehicles EV, HV is the one of the automatic shift control apparatus for an electric vehicle structure 1 or an electric vehicle that moment mounted fuel consumption and cruising distance estimator 14 of the electric vehicle, according to the present invention. The electric vehicle may be an electric vehicle EV that includes only the motor as a driving source, or may be a hybrid electric vehicle HV that includes the motor 3 and the engine E.

An automatic shift control device for an electric vehicle according to the present invention is equipped with a drive unit comprising a motor, an inverter that applies drive power to the motor, and an automatic transmission that shifts the rotation of the motor and transmits the rotation to wheels. In an electric vehicle having only the motor as a drive source or a hybrid type electric vehicle having the motor and an engine, the device controls the automatic transmission, and each gear ratio or each gear stage of the automatic transmission Drive unit efficiency calculating means for calculating the drive unit efficiency, which is the overall efficiency of the drive unit, and optimum gear ratio / shift speed determining means for determining the gear ratio or gear speed at which the calculated drive unit efficiency is maximized And a shift command output means for setting the gear ratio or shift speed determined to be the highest in the automatic transmission, and the drive The knit efficiency calculating means calculates the inverter efficiency, the motor efficiency, and the transmission efficiency, and calculates the drive unit efficiency using these three efficiencies. The knit efficiency calculating means changes according to the gear stage in addition to the inverter efficiency and the motor efficiency. transmission efficiency and shall be considered, the automatic transmission is located continuously form capable of selecting an arbitrary speed ratio within a certain range, the drive unit efficiency calculating means multiple selectable The drive unit efficiency at the gear ratio is calculated, the optimum gear ratio / shift speed determining means determines the highest gear ratio by comparing the plurality of drive unit efficiencies that have been calculated, and the shift command output means is the highest. The drive unit efficiency calculating means sets the calculated gear ratio at regular intervals, and sets the optimum gear ratio. Because shift stage determining unit was determined and the gear ratio of the highest gear ratio drive unit efficiency from the drive unit efficiency estimating the maximum and becomes the gear ratio and the estimated in the transmission ratio of the constant interval, which is the operation, drive It is possible to estimate the gear ratio and gear stage with the best efficiency of the entire unit with high accuracy, and by using the gear ratio and gear step with the best estimated with high accuracy, one charge cruising The distance can be improved.

The instantaneous fuel consumption / cruising distance estimation device for an electric vehicle according to the present invention includes the automatic transmission control device having the above-described configuration , so that the instantaneous fuel consumption when traveling using the best gear ratio and gear stage estimated with high accuracy is provided. And cruising distance can be estimated.

It is explanatory drawing which combined the conceptual diagram which shows the electric vehicle of only a motor drive carrying the automatic transmission control apparatus which concerns on one Embodiment of this invention by planar view, and the block diagram of the control system. It is explanatory drawing which combined the conceptual diagram which shows the hybrid type electric vehicle carrying the automatic transmission control apparatus which concerns on the embodiment in planar view, and the block diagram of the control system. It is a block diagram which shows the conceptual structure of the power running time calculating system of the automatic transmission control apparatus, Comprising: It is the figure which excluded a part of the means at the time of regeneration calculating. FIG. 2 is a block diagram showing a conceptual configuration of a regeneration time calculation system of the automatic transmission control device, in which a part of powering time calculation means is omitted. It is a calculation flowchart at the time of vehicle power running in the automatic transmission control device. 5 is a shift control flowchart for powering in an automatic transmission capable of selecting an arbitrary gear ratio continuously within a certain range in the automatic transmission control device. It is a shift control flowchart at the time of regeneration in the automatic shift control device. 4 is a speed change control flowchart for regeneration in an automatic transmission capable of continuously selecting an arbitrary speed ratio within a certain range in the automatic speed change control device.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an example of an electric vehicle EV provided with an automatic transmission control device 1 according to this embodiment, and is a type including only a motor 3 as a travel drive source. In this electric vehicle EV, wheels 7 as a pair of left and right front wheels installed in a vehicle body 6 are driven wheels driven by a motor-driven drive unit 2. The pair of left and right wheels 8 serving as rear wheels serve as driven wheels.

  The drive unit 2 includes a motor 3, an automatic transmission 4 that shifts the rotation of the motor 3 and transmits it to the wheels 7, and an inverter 5 that converts DC power of the battery 9 into AC power and applies it to the motor 3. Become. The motor 3 is a synchronous motor such as an IPM motor (embedded permanent magnet synchronous motor). A differential 4 a that distributes the rotational output to the axles 10 of the left and right wheels 7 is provided at the rear stage of the automatic transmission 4. The automatic transmission 4 is a transmission that performs a shift operation with an electric signal from a vehicle control system without using manual control. It is also possible to use a format in which an arbitrary gear ratio can be selected continuously.

  In FIG. 2, a pair of left and right front wheels 7 is a main drive wheel driven by the engine E, and a pair of left and right rear wheels 8 is an auxiliary drive wheel driven by the motor-driven drive unit 2. A hybrid electric vehicle HV is shown. This hybrid electric vehicle HV is provided with a transmission T for shifting the rotation of the engine E, and a differential D for distributing the rotation output from the transmission T to the wheels 7 as the left and right front wheels.

  In the electric vehicles EV and HV in FIGS. 1 and 2, the control system controls the motor 3 by driving the ECU 11, which is an electric control unit that performs overall control and cooperative control of the entire vehicle. And an inverter device 12 for performing. The inverter device 12 includes an inverter 5 and an inverter control circuit (not shown) that controls the inverter 5. The inverter 5 is composed of a combination of switching elements, and switches the DC power of the battery 9 to a three-phase AC power, such as an IGBT module, and opens and closes each switching element of the strong circuit section by PWM control or the like. And a PWM control unit. The inverter control circuit gives a drive signal to the PWM control unit of the inverter 5 in accordance with a torque command given from the ECU 11, detection of the phase angle and rotation speed of the motor 3, and the like.

  Although the automatic transmission control device 1 is shown as a part of the main ECU 11 in the examples of FIGS. 1 and 2, the automatic transmission control device 1 may be configured as an ECU dedicated to transmission or as a part of the inverter device 11. Also good.

  FIG. 3 is a block diagram showing an internal configuration and the like of the automatic transmission control device 1. The automatic transmission control device 1 is an optimum transmission ratio and shift speed calculation device, and includes a drive unit efficiency calculation means 21, an optimum transmission ratio / shift speed determination means 22, and a shift command output means 23. The drive unit efficiency calculation means 21 is a means for calculating the drive unit efficiency, which is the overall efficiency of the drive unit 2. The drive unit efficiency can be expressed as a product of three efficiencies: inverter efficiency, motor efficiency, and transmission efficiency. The optimum gear ratio / shift speed determination means 22 is a means for determining the speed ratio or shift speed at which the drive unit efficiency calculated by the drive unit efficiency calculation means 21 is maximized. The optimum gear ratio / gear stage determining means 22 is continuously selected in the range of the optimum gear stage when the automatic transmission 4 of the drive unit 2 is a shift stage switching type. In the case of a type in which the transmission ratio can be selected, the optimum transmission ratio is calculated. The shift command output means 23 is a means for outputting a shift command for setting, in the automatic transmission 4, the shift speed or gear ratio determined to be the highest.

  The drive unit efficiency calculating unit 21 includes an efficiency calculating unit 21a including an inverter efficiency calculating unit 24, a motor efficiency calculating unit 25, and a transmission efficiency calculating unit 26 for calculating inverter efficiency, motor efficiency, and transmission efficiency, respectively. Drive unit total efficiency calculation means 21b that calculates a drive unit that is the overall efficiency of the drive unit 2 from the inverter efficiency, the motor efficiency, and the transmission efficiency calculated by each efficiency calculation device 21a. The drive unit efficiency calculation means 21 has motor torque command value calculation means 27 for calculating the motor torque command value and motor rotation speed calculation means 28 for calculating the motor rotation speed in front of each efficiency calculation device 21a. A command value / motor rotation number calculation device 21c is provided. Before the motor torque command value / motor rotation number calculation device 21c, a driver request is issued from the acceleration command value (hereinafter referred to as "accelerator pedal opening" or "accelerator pedal depression amount") of the accelerator operation means 31 operated by the driver. A means 34 for calculating vehicle torque is provided in the ECU 11 (FIGS. 1 and 2).

  Although FIG. 3 is shown with each means functioning during regeneration omitted, the drive unit efficiency calculating means 21 further includes a provisional motor rotation speed calculating device 21d as shown in FIG. A value calculating means 35 is provided in the ECU 11.

  1 and 2, the ECU 11 is provided with instantaneous fuel consumption / cruising distance estimation means 13 for estimating the instantaneous fuel consumption and the cruising distance using the maximum drive unit efficiency calculated by the automatic transmission control device 1. The instantaneous fuel consumption / cruising distance estimation means 13 and the drive unit efficiency calculation means 21 of FIG. 3 constitute an instantaneous fuel consumption / cruising distance estimation device 14 for an electric vehicle.

  The operation and effect of the automatic transmission control device 1 having the above configuration will be described. The drive unit efficiency, which is the overall efficiency of the drive unit 2, can be expressed by the product of three efficiencies: inverter efficiency, motor efficiency, and transmission efficiency. The input power from the battery 9 becomes power for driving the wheels 7 and (8) via the inverter 5 and the motor 3 and the automatic transmission 4. In this transmission path, inverter loss, motor loss, and transmission loss occur. These losses vary depending on the gear ratio and the gear position. Therefore, in this embodiment, the drive unit efficiency when traveling at each gear ratio and gear stage is calculated and compared, and the gear ratio and gear stage that provides the best drive unit efficiency are selected as travel gears and the gears are shifted. Run. This makes it possible to travel with the highest drive unit efficiency, and to improve the one-charge cruising range.

Further, in this embodiment, there is provided instantaneous fuel consumption / cruising distance estimating means 13 for estimating the instantaneous fuel consumption and cruising distance using the maximum drive unit efficiency calculated by the drive unit efficiency calculating means 21, and these instantaneous fuel consumption / cruising distance are provided. The estimation means 13 and the drive unit efficiency calculation means 21 constitute an instantaneous fuel consumption / cruising distance estimation device 14 for an electric vehicle.
Since the drive unit efficiency calculation means 21 can estimate the drive unit efficiency with high accuracy as described above, the instantaneous fuel consumption meter mounted in many automobiles and the display accuracy of the estimated cruising distance are used in the instant fuel consumption / An improvement effect can be expected by the cruising distance estimation device 14.

  The outline of the configuration and function of each device and each means shown in FIG. 3 and FIG. 4 is as described above in the section of [Means for Solving the Problems]. This will be described later together with flowcharts shown in FIGS.

The automatic transmission 4 may be of a type having a plurality of shift speeds, or of a type capable of continuously selecting an arbitrary gear ratio within a certain range.
In the case of the automatic transmission 4 having a plurality of shift speeds, the drive unit efficiency calculating means 21 calculates the drive unit efficiency at each shift speed, and the optimum gear ratio / shift speed determining means 22 has a drive unit efficiency. The shift stage that is the highest is determined, and the shift command output means 23 sets the shift stage that is determined to be the highest in the automatic transmission 4.

When the automatic transmission 4 is in a format that can continuously select an arbitrary gear ratio within a certain range, for example, in the case of a continuously variable transmission, the gear ratio that maximizes the drive unit efficiency is calculated. However, this gear ratio may be set to the gear ratio of the transmission.
That is, the drive unit efficiency calculating means 21 calculates the drive unit efficiency at a plurality of selectable gear ratios, and the optimum speed ratio / speed stage determining means 22 compares the calculated drive unit efficiencies. It is also possible to determine the maximum gear ratio, and the shift command output means 23 may set the gear ratio determined to be the highest in the automatic transmission 4.
The above-mentioned “calculate the drive unit efficiency at a plurality of selectable gear ratios” means to calculate the drive unit efficiency at a plurality of gear ratios with arbitrarily determined intervals in the case of a continuous shift.

  In this case, the gear ratio can be selected infinitely finely, and the drive unit efficiency at all the selected gear ratios may be obtained. However, if the drive unit efficiency for each gear ratio selected infinitely finely is calculated, an enormous amount of time is required. In the worst case, computation may be impossible. In order to avoid such a phenomenon and to prevent the optimum gear selection failure and drive feeling deterioration due to calculation delay, the calculated gear ratio is set at regular intervals (for example, the selectable gear ratio range is divided into ten). The speed ratio that provides the best drive unit efficiency may be estimated from the drive unit efficiency at the speed ratio at regular intervals.

Specifically, the drive unit efficiency is the best from the drive unit efficiency at a fixed gear ratio (temporary maximum efficiency point), the drive unit efficiency η _max , η _max-1 , η before and after that point. _{max + 1} and gear ratios i _max , i _max-1 , i _{max + 1} are selected and the best drive unit efficiency point is estimated from the three points using a quadratic function, and the number of points is increased to a higher order function Can be used to estimate the best drive unit efficiency point, and again to divide every predetermined interval within the gear ratio range extracted at the three points and repeatedly estimate the best drive unit efficiency point. A method may be used.

  More specifically, the drive unit efficiency calculating means 21 sets the gear ratio to be calculated at regular intervals, and the optimum gear ratio / shift speed determining means 22 is the drive unit efficiency at the calculated gear ratio at regular intervals. From the above, the gear ratio with the highest drive unit efficiency is estimated, and the estimated gear ratio is determined as the highest gear ratio.

  In addition, the optimum speed ratio / speed stage determination means 23 obtains a provisional maximum efficiency point and a plurality of points before and after the speed ratio at the fixed intervals, and obtains a high value from information on the provisional maximum efficiency point and a plurality of points before and after that. An optimal transmission ratio estimation method for estimating a transmission ratio that achieves the best drive unit efficiency using a secondary function may be used.

  The optimum gear ratio / speed stage determining means 22 obtains a provisional maximum efficiency point and one point before and after that at the gear ratio at regular intervals, and uses the quadratic function from the information of the three points to determine the best drive unit. An optimum transmission ratio estimation method for estimating a transmission ratio that achieves efficiency may be used.

  The optimum speed ratio / speed stage determining means 23 obtains a provisional maximum efficiency point and a point before and after it at the speed ratio at regular intervals, and compares the efficiency at one point before and after. And determining that the speed ratio that achieves the best drive unit efficiency is between the speed ratio at the provisional maximum efficiency point and the determined speed ratio. An optimum speed ratio estimation method may be used in which the range of the ratio and the determined speed ratio is further divided at regular intervals and the best drive unit efficiency is repeatedly calculated.

The above action is an action at the time of power running in which the power of the motor 3 is transmitted to the wheels via the drive system, but is not limited to at the time of power running but also at the time of power running at the time of regeneration in which the motor 3 absorbs the kinetic energy of the wheels via the drive system. Has the same effect. That is, it is possible to recover a larger amount of electric power by shifting to a gear ratio and gear position that provides the best regenerative efficiency of the entire drive unit 2, and to improve one charge cruising distance.
In the case of power running, the motor torque command value can be changed according to the accelerator pedal operation amount. Therefore, it is possible to calculate the efficiency by using the motor torque command value and the motor rotation speed obtained from the vehicle speed and the gear position or the gear ratio within the conditions satisfying the vehicle torque required by the driver as the variable parameters. On the other hand, in the case of regeneration, unlike the case of powering, the SOC of the battery also affects the motor torque command value is not determined only by the brake pedal operation amount. Therefore, the regenerative motor torque command value calculating means 35 may be provided, and the efficiency may be calculated using only the motor rotation number as a variable parameter, with the regenerative motor torque command value calculated by the regenerative motor torque command value calculating means 35 unchanged. Incidentally, the vehicle torque is the torque transmitted to the wheels, that is, the torque after the output torque of the traveling motor is amplified by the speed reducer.

  In this embodiment, the drive unit efficiency calculating means 21 may use a regenerative motor torque command value as a fixed value during regeneration, and only change the motor speed as a parameter to be changed according to the gear ratio or gear position.

  FIG. 5 is a flowchart during powering by motor drive. In step S1, the vehicle torque requested by the driver is calculated by the driver-requested vehicle torque calculation device 34 (FIG. 3) from the accelerator pedal opening of the driver. Based on the calculated driver-requested vehicle torque and the current vehicle speed detected by the vehicle speed detecting means 32, the motor torque calculation is performed by calculating the provisional motor torque command value and the provisional motor rotation speed for each selectable gear ratio or gear position. The calculation is performed by the means 27 and the motor rotation number calculating means 28 (S2).

  From the current oil temperature detected by the oil temperature detecting means 33, the provisional motor torque command value calculated in step S2, and the provisional motor rotation speed, provisional inverter efficiency, motor efficiency, and gear change at each gear ratio or each gear stage. The machine efficiency is calculated by the inverter efficiency calculation means 24, the motor efficiency calculation means 25, and the transmission efficiency calculation means 26 (S3). From the calculated temporary inverter efficiency, motor efficiency, and transmission efficiency, the drive unit efficiency at each gear ratio or each gear stage is calculated by the drive unit overall efficiency calculation means 21b (S4).

  The drive unit efficiency is calculated from individual efficiency maps (inverter efficiency, motor efficiency, transmission efficiency), from a method using an efficiency map in which the inverter efficiency map and motor efficiency map are combined, from experiments and theoretical formulas. A method using the derived efficiency map or a combination of these can be considered, but any method may be used.

  Based on the gear ratios or the drive unit efficiencies at the respective gear speeds obtained in step S4, the gear ratio or gear speed with the highest drive unit efficiency is selected by the optimum gear ratio / speed gear determining means 22 (S5).

  The shift command output means 23 compares the selected gear ratio or shift speed with the current gear ratio or shift speed (S6). If they are different, a shift command for shifting to the selected gear ratio or shift speed is transmitted to the automatic transmission 4. (S8). If the selected gear ratio or gear position matches the current gear ratio or gear step, the current gear ratio or gear stage is maintained (S7).

FIG. 6 shows an example of a shift control flowchart during powering when the automatic transmission 4 is configured to be able to continuously select an arbitrary gear ratio within a certain range.
In step R1, the vehicle torque requested by the driver is calculated by the driver-requested vehicle torque calculation device 34 (FIG. 3) from the accelerator pedal opening of the driver.
Based on the current vehicle speed detected by the vehicle speed detection means 32 and the driver-requested vehicle torque calculated in step R1, the provisional motor torque command value and the provisional motor rotation speed at a constant gear ratio are obtained from the motor torque calculation means 27 and The motor rotation number calculation means 28 calculates each (R2).

  From the current oil temperature detected by the oil temperature detection means 33, the provisional motor torque command value calculated in step R2, and the provisional motor rotation speed, provisional inverter efficiency, motor efficiency, and transmission efficiency at a gear ratio at regular intervals. Is calculated by the inverter efficiency calculating means 24, the motor efficiency calculating means 25, and the transmission efficiency calculating means 26, respectively (R3). Based on the provisional inverter efficiency, motor efficiency, and transmission efficiency thus obtained, the drive unit efficiency at a gear ratio at regular intervals is calculated (R4).

  The drive unit efficiency calculation method is derived from individual efficiency maps (inverter efficiency, motor efficiency, transmission efficiency), a method using an efficiency map in which the inverter efficiency map and motor efficiency map are combined, and experimental and theoretical formulas. A method using an efficiency map, or a combination thereof, can be considered, but any method may be used.

From the drive unit efficiency at the gear ratio at fixed intervals determined in step R4 by the optimum gear ratio / speed stage determination means 22, the drive unit efficiency η _{max is the} point at which the drive unit efficiency is highest, one point before, one point after. , Η _max−1 , η _{max + 1} and gear ratios i _max , i _max−1 , i _{max + 1} are selected (R5).
From the selected three points (i _max , η _max ), (i _max−1 , η _max−1 ), (i _{max + 1} , η _{max + 1} ), the optimum gear ratio i _max ｀ is obtained. As an example, there is a method in which the drive unit efficiency is expressed as a quadratic function of the gear ratio from the three points, and the gear ratio at which the drive unit efficiency is an extreme value is regarded as the optimum gear ratio, as in the following equation.

  The speed change command output means 23 compares the optimum speed ratio obtained in step R6 with the current speed ratio (R7), and if different, outputs a speed change command for shifting to the obtained optimum speed ratio (R9). If the calculated optimum gear ratio matches the current gear ratio, the current gear ratio is maintained (R8).

FIG. 7 shows an example of a shift control flowchart during regeneration. The regenerative motor torque command value is calculated by the regenerative motor torque command value calculation means 35 from information such as the accelerator pedal opening by the driver's operation, the battery SOC from the battery SOC detection means 37, and the deceleration command value of the brake operation means 36. (Q1).
Based on the current vehicle speed obtained from the vehicle speed detection means 32, the provisional motor rotation speed is calculated by the motor rotation speed calculation means 28 for each selectable gear ratio or gear position (Q2).

From the current oil temperature, the regenerative motor torque command value calculated in step Q1, and the provisional motor rotation number calculated in step Q2, the provisional inverter efficiency, motor efficiency, and transmission efficiency at each gear ratio or each gear stage are obtained. The inverter efficiency calculation means 24, the motor efficiency calculation means 25, and the transmission efficiency calculation means 26 perform calculations (Q3), respectively.
Based on the obtained provisional inverter efficiency, motor efficiency, and transmission efficiency, the drive unit efficiency at each gear ratio or each gear stage is calculated by the drive unit overall efficiency calculating means 21b (Q4).

  The drive unit efficiency calculation method is derived from individual efficiency maps (inverter efficiency, motor efficiency, transmission efficiency), a method using an efficiency map in which the inverter efficiency map and motor efficiency map are combined, and experimental and theoretical formulas. A method using an efficiency map, or a combination thereof, can be considered, but any method may be used.

  The optimum gear ratio / gear stage determining means 22 selects the gear ratio or gear stage with the best drive unit efficiency from the gear ratios obtained in step Q4 or the drive unit efficiency at each gear stage (Q5).

  The speed change command output means 23 compares the speed ratio or speed selected in step Q5 with the current speed ratio or speed (Q6), and outputs a speed change command for shifting to the selected speed ratio or speed if different. (Q8). If the selected gear ratio or gear position matches the current gear ratio or gear step, the current gear ratio or gear stage is maintained (Q7).

  FIG. 8 shows an example of a shift control flowchart during regeneration in the automatic transmission 4 that can continuously select an arbitrary gear ratio within a certain range. The regenerative motor torque command value calculation means 35 calculates the regenerative motor torque command value from information such as the accelerator pedal opening by the driver's operation, the battery SOC from the battery SOC detection means 37, and the deceleration command value of the brake operation means 36. (P1). Based on the current vehicle speed obtained from the vehicle speed detection means 32, the provisional motor rotation speed at a fixed gear ratio is calculated by the motor rotation speed calculation means 28 (P2).

  Based on the current oil temperature, the regenerative motor torque command value calculated in step P1, and the temporary motor rotation speed calculated in step Q2, the temporary inverter efficiency, motor efficiency, and transmission efficiency at a fixed gear ratio are converted into inverters. The calculation is performed by the efficiency calculating means 24, the motor efficiency calculating means 25, and the transmission efficiency calculating means 26 (P3). Based on the obtained temporary inverter efficiency, motor efficiency, and transmission efficiency, the drive unit efficiency at a constant gear ratio is calculated by the drive unit overall efficiency calculation means 21b (P4).

  The drive unit efficiency calculation method is derived from individual efficiency maps (inverter efficiency, motor efficiency, transmission efficiency), a method using an efficiency map in which the inverter efficiency map and motor efficiency map are combined, and experimental and theoretical formulas. A method using an efficiency map, or a combination thereof, can be considered, but any method may be used.

From the drive unit efficiency at the gear ratio at regular intervals determined in step P4 by the optimum gear ratio / shift stage determination means 22, the drive unit efficiency η _{max is the} point at which the drive unit efficiency is the best, one point before, one point after. , Η _max−1 , η _{max + 1} and gear ratios i _max , i _max−1 , i _{max + 1} are selected (P5).
From the selected three points (i _max , η _max ), (i _max−1 , η _max−1 ), (i _{max + 1} , η _{max + 1} ), the optimum gear ratio i _max ｀ is obtained (P6). As an example, there is a method in which the drive unit efficiency is expressed as a quadratic function of the gear ratio from the three points, and the gear ratio at which the drive unit efficiency is an extreme value is regarded as the optimum gear ratio.

  The speed change command output means 23 compares the optimum speed ratio obtained in step P6 with the current speed ratio (P7), and if different, outputs a speed change command for shifting to the obtained optimum speed ratio (P9). If the calculated optimum gear ratio matches the current gear ratio, the current gear ratio is maintained (P8).

DESCRIPTION OF SYMBOLS 1 ... Automatic transmission control apparatus 2 ... Drive unit 3 ... Motor 4 ... Automatic transmission 4a ... Differential 6 ... Vehicle body 7, 8 ... Wheel 9 ... Battery 11 ... ECU
DESCRIPTION OF SYMBOLS 12 ... Inverter apparatus 13 ... Instantaneous fuel consumption / cruising distance estimation means 14 ... Instantaneous fuel consumption / cruising distance estimation apparatus 21 ... Drive unit efficiency calculation means 21a ... Each efficiency calculation apparatus 21b ... Drive unit whole efficiency calculation means 21c ... Motor torque command value Motor rotation speed calculation device 21d ... Temporary motor rotation speed calculation device 22 ... Optimal gear ratio / speed stage determination means 23 ... Shift command output means 24 ... Inverter efficiency calculation means 25 ... Motor efficiency calculation means 26 ... Transmission efficiency calculation means 27 ... Motor torque command value calculating means 28 ... motor rotation speed calculating means 35 ... regenerative motor torque command value calculating means E ... engine EV, HV ... electric vehicle

Claims (6)

A drive unit comprising a motor, an inverter that applies drive power to the motor, and an automatic transmission that shifts the rotation of the motor and transmits the rotation to the wheels, and is provided with only the motor as a travel drive source, or In a hybrid electric vehicle comprising a motor and an engine, the device controls the automatic transmission,
Drive unit efficiency calculation means for calculating the drive unit efficiency, which is the overall efficiency of the drive unit, at each gear ratio or each gear stage of the automatic transmission, and a gear ratio or ratio at which the calculated drive unit efficiency is maximum An optimum gear ratio / shift speed determining means for determining a shift speed, and a shift command output means for setting the speed ratio or shift speed determined to be the highest in the automatic transmission;
The drive unit efficiency calculating means calculates the inverter efficiency, motor efficiency, and the transmission efficiency is shall be calculates a drive unit efficiency using these three efficient,
The automatic transmission has a format capable of continuously selecting an arbitrary gear ratio within a certain range, and the drive unit efficiency calculating means calculates drive unit efficiency at a plurality of selectable gear ratios, The optimum gear ratio / shift speed determining means compares the drive unit efficiencies for which the calculation has been performed to determine the highest gear ratio, and the shift command output means automatically determines the gear ratio determined to be highest. Set in the machine,
The drive unit efficiency calculating means sets the gear ratio to be calculated at regular intervals, and the optimum gear ratio / shift speed determining means has the highest drive unit efficiency from the drive unit efficiency at the calculated gear ratio at regular intervals. automatic shift control apparatus for an electric vehicle characterized by the this determines that gear ratio to estimate a gear ratio becomes maximum, and the estimated gear ratio. 2. The optimum gear ratio / shift speed determining means according to claim 1 , wherein a provisional maximum efficiency point and a plurality of points before and after the gear ratio at each fixed interval are obtained, and a high value is obtained from information on the provisional maximum efficiency point and a plurality of points before and after the provisional maximum efficiency point. An automatic transmission control apparatus for an electric vehicle using an optimum transmission ratio estimation method for estimating a transmission ratio that achieves the best drive unit efficiency using a second-order function. 2. The optimum gear ratio / shift speed determining means according to claim 1 , wherein a provisional maximum efficiency point and one point before and after the gear ratio at each fixed interval are obtained, and the best using a quadratic function from the information of the three points. An automatic transmission control device for an electric vehicle using an optimum transmission ratio estimation method for estimating a transmission ratio for realizing drive unit efficiency. According to claim 1, wherein the optimal gear ratio shift speed determining means, the provisional maximum efficiency point and the transmission ratio of the fixed intervals determined one by before and after a point, the provisional maximum efficiency point by comparing the efficiency of around 1 point It is estimated that the speed ratio that achieves the best drive unit efficiency is between the speed ratio of the provisional maximum efficiency point and the determined speed ratio, and the estimated provisional maximum efficiency point An automatic transmission control device for an electric vehicle using an optimum transmission ratio estimation method that further divides the range of the transmission ratio and the determined transmission ratio at regular intervals and repeatedly calculates the best drive unit efficiency. A drive unit comprising a motor, an inverter that applies drive power to the motor, and an automatic transmission that shifts the rotation of the motor and transmits the rotation to the wheels, and is provided with only the motor as a travel drive source, or In a hybrid electric vehicle comprising a motor and an engine, the device controls the automatic transmission,
Drive unit efficiency calculation means for calculating the drive unit efficiency, which is the overall efficiency of the drive unit, at each gear ratio or each gear stage of the automatic transmission, and a gear ratio or ratio at which the calculated drive unit efficiency is maximum An optimum gear ratio / shift speed determining means for determining a shift speed, and a shift command output means for setting the speed ratio or shift speed determined to be the highest in the automatic transmission;
The drive unit efficiency calculation means calculates inverter efficiency, motor efficiency, and transmission efficiency, and calculates drive unit efficiency using these three efficiencies,
The drive unit efficiency calculating means is an automatic transmission control device for an electric vehicle in which a regenerative motor torque command value is set as a fixed value during regeneration, and a parameter to be changed according to a gear ratio or a shift speed is only a motor rotational speed. A drive unit comprising a motor, an inverter that applies drive power to the motor, and an automatic transmission that shifts the rotation of the motor and transmits the rotation to the wheels, and is provided with only the motor as a travel drive source, or In a hybrid electric vehicle comprising a motor and an engine, the device controls the automatic transmission,
Drive unit efficiency calculation means for calculating the drive unit efficiency, which is the overall efficiency of the drive unit, at each gear ratio or each gear stage of the automatic transmission, and a gear ratio or ratio at which the calculated drive unit efficiency is maximum An optimum gear ratio / shift speed determining means for determining a shift speed, and a shift command output means for setting the speed ratio or shift speed determined to be the highest in the automatic transmission;
The drive unit efficiency calculating means calculates an inverter efficiency, a motor efficiency, and a transmission efficiency, and uses these three efficiencies to calculate a drive unit efficiency, and an automatic transmission control device for the electric vehicle. An instantaneous fuel consumption / cruising distance estimation device for an electric vehicle comprising instantaneous fuel consumption / cruising distance estimating means for estimating instantaneous fuel consumption and cruising distance using the calculated maximum drive unit efficiency.

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