Control device of electric vehicle

Abstract

To provide an electric vehicle that allows a driver to properly experience a similar operational feeling to a conventional vehicle equipped with a transmission without deteriorating stability and operability of the vehicle.SOLUTION: A control device of an electric vehicle which uses a motor as a driving power source sets required drive torque in multiple ranges with stepwisely different torque characteristics with respect to the rotational speed (or vehicle speed) of a motor, controls output torque of the motor on the basis of the required drive torque set according to the range selected by a shift device, and determines the propriety of switching of the actual range by the continuous switching operation of the ranges on the basis of the required drive torque set in the range of the switching destination (step S4) when the continuous switching operation for switching from the selected range to the other range that is different by two or more stages is performed.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a control device for an electric vehicle that uses a motor as a driving force source. [Background technology]

[0002] Patent Document 1 describes an electric vehicle (electrically-driven vehicle) that aims to simulate the shifting operation of a vehicle equipped with a manual transmission (MT vehicle). The electric vehicle described in Patent Document 1 includes a shift device and a clutch device operated by a driver. The shift device and the clutch device are simulated devices that are assumed to be installed in an MT vehicle, and the clutch device is operated in conjunction with the operation of the shift device by the driver. The electric vehicle described in Patent Document 1 also includes a torque control unit that controls the output torque of a motor that is a driving force source. The torque control unit controls the output torque of the motor according to the operation amount of the clutch device. In addition, the shift device is configured to select one of a plurality of modes (or ranges) in which the torque characteristics relative to the rotation speed of the motor are gradually different, and the torque control unit controls the output torque of the motor according to the mode selected by the shift device.

[0003] Furthermore, Patent Document 2 describes an electric vehicle that aims to give the driver the sensation of driving a manual vehicle (MT vehicle). The electric vehicle described in Patent Document 2 includes a motor for driving, a shift lever operated by the driver, a torque map that specifies the torque value (required drive torque or target drive torque) to be instructed to the motor, and a control device in which the torque map is set. The torque map is set for each virtual gear stage corresponding to each of a plurality of shift positions. The control device determines the torque value using the torque map for the virtual gear stage corresponding to the shift position selected by the shift lever, and controls the output torque of the motor.

[0004] The electric vehicle described in Patent Document 3 includes a paddle switch and a shifter (such as a shift lever) electrically connected to an ECU (controller). The ECU controls the output torque of the motor according to the accelerator pedal opening using a torque map that defines the relationship between the accelerator pedal opening and the motor output torque. At the same time, the ECU changes the torque map used to control the motor output torque based on the driver's operation of the paddle switch or shifter. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2021-118569 A [Patent Document 2] JP 2020-156260 A [Patent Document 3] Patent Publication No. 2022-12205 Summary of the Invention [Problem to be solved by the invention]

[0006] A motor mounted on an electric vehicle as a driving force source can output a large torque when starting or running at a low speed. Therefore, there are electric vehicles that are not mounted with a transmission for amplifying the driving torque. None of the electric vehicles described in the above patent documents are mounted with an actual transmission, but are provided with a shift device, a shift switch, or the like similar to the conventional ones. In addition, a plurality of modes or torque maps with different torque characteristics of the motor are set. In the electric vehicles described in the above patent documents, the modes or torque maps are switched by the driver's manual operation using a shift device, a shift switch, or the like, so that it is assumed that the electric vehicles are mounted with a transmission similar to the conventional ones. Therefore, according to the electric vehicles described in Patent Document 1 and Patent Document 2, the driver can experience the same driving operation sensation and vehicle behavior as a MT vehicle equipped with a conventional manual transmission. Also, according to the electric vehicle described in Patent Document 3, the driver can experience the same feeling of manual shifting operation (sequential shift) using a paddle switch, a shift lever, or the like similar to a vehicle equipped with a conventional multi-speed transmission.

[0007] However, when the output torque of the motor is controlled by setting a plurality of modes or torque maps as in the electric vehicles described in the above patent documents, the stability of the electric vehicle may be reduced. For example, when a switching operation to a mode (or range) that differs by two or more steps is performed in a short time, or when a continuous switching operation across ranges is performed, and the torque characteristics of the motor are switched in response to such an operation, the output torque of the motor changes suddenly. That is, the driving force of the electric vehicle changes suddenly. In particular, when the mode is switched in a direction corresponding to a downshift in a conventional transmission, the driving force increases suddenly, and as a result, there is a risk that the tires will slip and the behavior of the electric vehicle will become unstable. In order to avoid such a sudden change in the driving force of the electric vehicle, it is also possible to prohibit the switching operation to a mode that differs by two or more steps as described above, or the continuous switching operation across ranges. However, in that case, some of the switching operations that were possible in a conventional vehicle equipped with a transmission will be restricted. Therefore, the operability of the electric vehicle will be reduced compared to a conventional vehicle equipped with a transmission.

[0008] As described above, there is still room for improvement in constructing an electric vehicle that allows the driver to experience the same sensation of shifting as in the past, without reducing the operability of the vehicle or the stability of the vehicle behavior.

[0009] The present invention has been devised with an eye on the technical problems described above, and aims to provide an electric vehicle that allows the driver to appropriately experience an operating feel similar to that of a conventional vehicle equipped with a transmission, without compromising the operability and stability of the vehicle. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the present invention provides a control device for an electric vehicle that has at least a motor as a driving force source and controls the motor based on a control target value that is set corresponding to a required driving force, the control target value being set into a plurality of ranges in which the torque characteristics relative to the rotation speed of the motor differ in stages, the control device comprising: a shift device that selects one of the plurality of ranges in accordance with manual operation by a driver; and a controller that controls the output torque of the motor based on the control target value that is set in accordance with the range selected by the shift device, wherein when a continuous switching operation is performed to switch to another range that is two or more stages different from the range currently selected by the shift device, the controller determines whether or not the range can be switched by the continuous switching operation based on the control target value that is set in the range to be switched to.

[0011] In addition, the continuous switching operation in this invention may be an operation for switching to a range in a direction in which the control target value is larger than the currently selected range (i.e., a direction in which the output torque corresponding to the motor rotation speed is larger).

[0012] Furthermore, the controller in the present invention may be configured to permit range switching when the control target value set for the range to be switched to is equal to or less than a torque threshold value that determines whether or not the continuous switching operation is possible, and to reject the range switching when the control target value set for the range to be switched to is greater than the torque threshold value.

[0013] In addition, the torque threshold in this invention may be a setting that changes depending on the vehicle speed or the rotation speed, and the controller in this invention may be configured to allow the range switching when the control target value set in the destination range is equal to or less than the torque threshold corresponding to the vehicle speed or the rotation speed when the continuous switching operation is performed, and to reject the range switching when the control target value set in the destination range is greater than the torque threshold corresponding to the vehicle speed or the rotation speed when the continuous switching operation is performed.

[0014] In the present invention, the torque threshold value may be set to be larger as the vehicle speed or the rotation speed decreases.

[0015] In addition, the controller in the present invention may be configured to permit the range switching when the continuous switching operation is performed and to reject the range switching if the increase rate of the control target value set in the range to be switched to relative to the current control target value is equal to or less than a torque step threshold that determines whether the continuous switching operation is possible, and to reject the range switching if the increase rate is greater than the torque step threshold.

[0016] In addition, the torque step threshold in this invention may be a setting that changes depending on the vehicle speed or the rotation speed, and the controller in this invention may be configured to allow the range switching when the increase rate is equal to or less than the torque step threshold corresponding to the vehicle speed or the rotation speed when the continuous switching operation is performed, and to reject the range switching when the increase rate is greater than the torque step threshold corresponding to the vehicle speed or the rotation speed when the continuous switching operation is performed.

[0017] The torque step threshold value in the present invention may be set to be larger as the vehicle speed or the rotation speed decreases. Effect of the Invention

[0018] The electric vehicle to be controlled in the present invention uses at least one motor as a driving force source, and runs by generating a driving force by the output torque of the motor. The output torque of the motor is controlled based on a control target value set corresponding to the required driving force. The control target value, in other words, is a target driving torque or a required driving torque, and is set in a plurality of ranges in which the torque characteristics of the motor are gradually different, for example, in the form of a map. The plurality of ranges are selectively set by a shift device manually operated by a driver. Therefore, in the control device for an electric vehicle of the present invention, the torque characteristics of the motor and the control target value set based on the torque characteristics can be changed by switching the range by the shift device. For example, it is possible to switch from a range of standard torque characteristics to a range of torque characteristics that outputs a large torque at a low rotation speed. Therefore, even in an electric vehicle that does not use a transmission, it is possible to allow the driver to experience the same feeling of shifting as in a conventional vehicle equipped with a manual transmission or a multi-speed transmission.

[0019] Furthermore, in the control device for an electric vehicle of the present invention, when a continuous switching operation of the shift device is performed by the driver, it is determined whether or not to permit the actual switching of the range by the continuous switching operation. The continuous switching operation is an operation of switching from the currently selected range in the shift device to another range that is different by two or more steps, for example, an operation of switching to another non-contiguous range by skipping other consecutive ranges in a predetermined short time, or an operation of switching to another range by straddling adjacent other ranges. When the range is switched by such a continuous switching operation, the torque characteristics of the motor are significantly changed, and the driving force generated by the output torque of the motor also fluctuates significantly. As a result, there is a risk of shocks being generated or tires slipping, which may disturb the behavior of the electric vehicle. Therefore, in the control device for an electric vehicle of the present invention, when a continuous switching operation of the shift device is performed, it is determined whether or not the range can be switched by the continuous switching operation based on a control target value that is scheduled to be set in the range to be switched to. For example, if the control target value set in the switching destination range is greater than a predetermined threshold (torque threshold), or if the increase rate of the control target value set in the switching destination range relative to the current control target value is greater than a predetermined threshold (torque step threshold), it is determined that there is a possibility that the behavior of the electric vehicle will be disturbed, and range switching by the continuous switching operation is rejected. If the control target value set in the switching destination range is equal to or less than the torque threshold, or if the increase rate of the control target value set in the switching destination range relative to the current control target value is equal to or less than the torque step threshold, it is determined that there is no possibility that the behavior of the electric vehicle will be disturbed, and range switching by the continuous switching operation is permitted. Therefore, the actual switching of the range by the continuous switching operation is appropriately performed in a stable state where there is no risk of disturbing the behavior of the electric vehicle. Then, by the range switching operation using the above-mentioned shift device, it is possible to simulate the shifting operation of a vehicle equipped with a transmission.

[0020] Therefore, according to the control device for an electric vehicle of the present invention, the driver can appropriately experience the same operating feel as a conventional vehicle equipped with a transmission, without compromising either the operability or stability of the vehicle. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration (drive system and control system) of an electric vehicle to be controlled in the present invention. [Diagram 2] FIG. 2 is a diagram showing the torque characteristics of a typical motor. [Diagram 3] FIG. 3 is a diagram showing an image of a map for calculating a required driving torque of the motor according to the vehicle speed (or the rotation speed of the motor) and the depression amount of the accelerator pedal. [Figure 4] FIG. 4 is a diagram showing an image of a map for calculating a required drive torque corresponding to a 50% depression amount of the accelerator pedal. [Diagram 5] FIG. 5 is a diagram showing an image of a shift device having a manual operation unit composed of a shift lever and a shift gate. [Figure 6] Fig. 6 is a diagram showing an image of a shift device having a manual operation unit provided on a steering wheel, Fig. 6(a) shows a shift switch provided on the steering wheel, and Fig. 6(b) shows a paddle switch provided on the steering wheel. [Figure 7] FIG. 7 is a diagram showing an image of a range switching operation (corresponding to a sequential shift) performed by a shift device having a manual operation unit. [Figure 8] FIG. 8 is a flowchart for explaining an example of control executed by the control device for an electric vehicle according to the present invention. [Figure 9] FIG. 9 is a time chart showing the range switching state when the control shown in the flowchart of FIG. 8 is executed. [Figure 10]FIG. 10 is a diagram showing an image of the torque threshold value used when the control shown in the flowchart of FIG. 8 is executed. [Figure 11] FIG. 11 is a diagram showing an image of the torque step threshold used when the control shown in the flowchart of FIG. 8 is executed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings. Note that the following embodiment is merely an example of a specific embodiment of the present invention, and is not intended to limit the present invention.

[0023] An example of a drive system and a control system of an electric vehicle to be controlled in an embodiment of the present invention is shown in schematic form in Fig. 1. An electric vehicle (hereinafter, vehicle) Ve shown in Fig. 1 is an electric vehicle equipped with a motor 1 as a drive power source. The vehicle Ve also includes a shift device 2, a detector 3, and a controller (ECU) 4.

[0024] The vehicle Ve to be controlled in the embodiment of the present invention may include one or more motors (not shown) as a driving force source in addition to the motor 1. Alternatively, the vehicle Ve may be a "hybrid vehicle" using the motor 1 and an engine (not shown) as a driving force source. As shown in FIG. 1, the vehicle Ve may be a front-wheel drive vehicle in which the output torque of the motor 1 is transmitted to front wheels (drive wheels) 6 via a reduction gear mechanism (not shown) or a differential gear 5, for example, and the front wheels 6 generate driving force. Alternatively, the vehicle Ve may be a rear-wheel drive vehicle (not shown) in which the output torque of the motor 1 is transmitted to rear wheels 7 via a propeller shaft (not shown), for example, and the rear wheels 7 generate driving force. Alternatively, the vehicle Ve may be a four-wheel drive vehicle (not shown) in which a transfer mechanism (not shown) is provided to transmit the output torque of the motor 1 to both the front wheels 6 and the rear wheels 7, and driving force is generated by both the front wheels 6 and the rear wheels 7.

[0025] The motor 1 is, for example, a permanent magnet synchronous motor or an induction motor. The motor 1 has at least a function as a prime mover that is driven by power supply and outputs torque. The motor 1 may also function as a generator that generates power by receiving torque from the outside and being driven. That is, the motor 1 may be a so-called motor-generator that combines a function as a prime mover and a function as a generator. A battery (not shown) is connected to the motor 1 via an inverter (not shown). Therefore, the motor 1 can be supplied with power stored in the battery to function as a prime mover and output driving torque. The motor 1 can also be made to function as a generator by the torque transmitted from the driving wheels 6, and the regenerative power generated at that time can be stored in the battery. The output speed and output torque of the motor 1 are electrically controlled by a controller 4 described later. For example, a required driving force is calculated from the amount of operation of an accelerator pedal (not shown) by the driver and the vehicle speed, and the output torque of the motor 1 is controlled based on a required driving torque (i.e., a control target value of the motor 1) that is set corresponding to the required driving force. As described later, the required drive torque is set, for example in the form of a map, into a plurality of ranges in which the torque characteristics of the motor 1 differ stepwise. One of the ranges is selected by the shift device 2, which will be described later, and the required drive torque corresponding to the selected range is set.

[0026] As shown in FIG. 2, the motor 1 has a unique torque characteristic. In FIG. 2, the torque characteristic of the motor 1 is shown with the vertical axis representing the required drive torque and the horizontal axis representing the vehicle speed. Considering the gear ratio between the motor 1 and the drive wheels 6, the vehicle speed on the horizontal axis may be considered as the rotation speed of the motor 1. The solid line in FIG. 2 shows the torque characteristic when there is no output restriction on the motor 1, and the dotted line shows the torque characteristic when there is an output restriction on the motor 1. The output restriction on the motor 1 is intended to reduce the load on the motor 1 in order to protect the motor 1, for example, when the temperature of the motor 1 is higher than a predetermined upper limit temperature, or conversely, when the temperature of the motor 1 is lower than a predetermined lower limit temperature. In addition, when the SOC of the battery is low or the temperature of the battery is low, the discharge restriction on the battery is performed, and the motor 1 is in a state equivalent to the state when the output restriction as described above is applied.

[0027] Further, the required drive torque of the motor 1 is set based on a map such as that shown in Fig. 3. The map shown in Fig. 3 shows the required drive torque according to the vehicle speed (or the rotation speed of the motor 1) and the depression amount of the accelerator pedal, based on the torque characteristics of the motor 1 shown in Fig. 2. Note that Fig. 3 shows the required drive torque calculated when the range of the required drive torque, which will be described later, is "D range" (standard driving range).

[0028] The required drive torque of the motor 1 as described above is set in a plurality of ranges in which the torque characteristics of the motor 1 differ stepwise, for example, in the form of a map as shown in FIG. 4. FIG. 4 shows a plurality of ranges of the required drive torque corresponding to, for example, a 50% depression amount of the accelerator pedal. In the example shown in FIG. 4, the required drive torques set in the "D range", "3 range", "2 range", and "L range (1 range)" are shown in order from the bottom. The "D range" is a range in which a standard required drive torque is set during normal driving. The "3 range" is a range in which a required drive torque one step higher than the "D range" is set. The "2 range" is a range in which a required drive torque one step higher than the "3 range" is set. And the "L range" is a range in which a required drive torque one step higher than the "2 range" is set.

[0029] In short, in the control device for an electric vehicle in the embodiment of the present invention, a map as shown in Fig. 3 and Fig. 4 above, i.e., a driving torque map, is provided in order to calculate a control target value when controlling the output torque of the motor 2, i.e., a required driving torque. The driving torque map is a map that sets the torque characteristics of the motor 2 with respect to the vehicle speed (or the rotation speed of the motor 2). The driving torque map in which the torque characteristics of the motor 2 as described above differ stepwise according to the amount of accelerator pedal operation (amount of driving force required by the driver) is set in a plurality of ranges.

[0030] The shift device 2 is manually operated by the driver, and selects one of the ranges of the torque characteristics of the motor 1, which are set in a plurality of stages as described above. That is, a drive torque map corresponding to one of the ranges is selected from the drive torque maps, which are set in a plurality of ranges. The vehicle Ve in the embodiment of the present invention is not actually equipped with a transmission as provided in a conventional engine vehicle. Therefore, the vehicle Ve does not originally require a "shift device" for shifting the transmission. The shift device 2, the ranges of the torque characteristics, which are set in a plurality of stages as described above, and the drive torque map are not intended to shift the actual transmission, but are provided as simulations so that the driver of the electric vehicle Ve can experience the feeling of shifting gears by manual operation, similar to that of the conventional vehicle.

[0031] Specifically, the shift device 2 has a manual operation unit 2a. The manual operation unit 2a is operated by manual operation by the driver to select one of a plurality of ranges. The shift device 2 outputs a switch signal corresponding to the range selected by the manual operation unit 2a. The switch signal is transmitted to a controller 4, which will be described later.

[0032] The manual operation unit 2a is composed of a shift lever 2b and shift gates 2c and 2d as shown in FIG. 5, for example. The shift device 2 shown in FIG. 5 has the same configuration as an existing "shift device" used in a vehicle equipped with a conventional automatic transmission (multiple-stage transmission), and the shift lever 2b is moved by the shift gate 2c shown on the left side of FIG. 5 to select one of the "drive (D) range", the "reverse (R) range", and the "parking (P) range". In addition, the shift device 2 shifts one step to a range in the direction in which the required driving torque becomes smaller by moving the shift lever 2b to the up (+) side by the shift gate 2d shown on the right side of FIG. 5. That is, the range is switched corresponding to an upshift in a conventional transmission. On the other hand, the shift lever 2b is moved to the down (-) side to shift one step to a range in the direction in which the required driving torque becomes larger. That is, the range is switched corresponding to a downshift in a conventional transmission.

[0033] The manual operation unit 2a is composed of, for example, shift switches 2e and 2f provided on a steering wheel 8, or paddle switches 2g and 2h provided on the steering wheel 8, as shown in FIG. 6. The shift device 2 shown in FIG. 6 has the same configuration as an existing "shift switch" or an existing "paddle switch" used in a vehicle equipped with a conventional automatic transmission (multiple-speed transmission). The shift switch (+ switch) 2e shown in FIG. 6(a) is provided, for example, on the back side of the spoke portion 8a of the steering wheel 8, and by operating (turning ON) this shift switch 2e once, the range is shifted one step to a direction in which the required driving torque becomes smaller. That is, the range is switched corresponding to an upshift in a conventional transmission. The shift switch (- switch) 2f shown in FIG. 6(a) is provided, for example, on the front side of the spoke portion 8a of the steering wheel 8, and by operating (turning ON) this shift switch 2f once, the range is shifted one step to a direction in which the required driving torque becomes larger. That is, a range change is performed that corresponds to a downshift in a conventional transmission. Similarly, by operating (turning ON) the paddle switch (UP switch) 2g shown in FIG. 6(b) once, the range is shifted one step to a direction in which the required drive torque becomes smaller. That is, a range change is performed that corresponds to an upshift in a conventional transmission. Also, by operating (turning ON) the paddle switch (DOWN switch) 2h shown in FIG. 6(b) once, the range is shifted one step to a direction in which the required drive torque becomes larger. That is, a range change is performed that corresponds to a downshift in a conventional transmission.

[0034] In the shift device 2 having the manual operation unit 2a as shown in FIG. 5 and FIG. 6, the range is switched as shown in FIG. 7. This is a switching operation similar to the so-called sequential shift when a conventional automatic transmission (multiple-speed transmission) is operated in manual mode. As shown in FIG. 7, when four ranges, namely, "D range", "3 range", "2 range", and "L range (1 range)", are set, for example, from the "D range", by operating the shift switch (- switch) 2f or the paddle switch (DOWN switch) 2h once, the "3 range" in which the required drive torque is increased by one level is selected, by operating the shift switch 2f or the paddle switch 2h twice, the "2 range" in which the required drive torque is increased by two levels is selected, and by operating the shift switch 2f or the paddle switch 2h three times, the "L range" in which the required drive torque is increased by three levels is selected. Conversely, from the "L range," operating the shift switch (+ switch) 2e or the paddle switch (UP switch) 2g once selects the "2 range," in which the required drive torque is reduced by one step; operating the shift switch 2e or the paddle switch 2g twice selects the "3 range," in which the required drive torque is reduced by two steps; and operating the shift switch 2e or the paddle switch 2g three times selects the "D range," in which the required drive torque is reduced by three steps.

[0035] Furthermore, the shift device 2 may be, for example, a simulated "shift device" assumed to be mounted on a MT vehicle, as described in the above-mentioned Patent Document 1. In the shift device 2 assumed to be a "shift device" for such a conventional MT vehicle, the shift lever (not shown) is configured to operate by tracing a shift pattern (or a shift gate) called an H pattern. For example, in the shift device 2 assumed to be a 6-speed "shift device," the first to sixth gear positions and the reverse (R) position are selectively set according to the position of the shift lever operated by the driver. In addition, in the shift device 2 assumed to be a "shift device" for such a conventional MT vehicle, the driver can perform a switching operation equivalent to a so-called jump shift operation, such as switching from a range corresponding to the sixth gear position to a range corresponding to the fourth gear position. Note that the vehicle Ve may be provided with a simulated "clutch device" assumed to be mounted on a MT vehicle, in addition to the shift device 2 assumed to be a "shift device" for a conventional MT vehicle as described above. The shift device 2 and the "clutch device" may be configured to be operated in conjunction with each other in the same manner as in driving a conventional MT vehicle.

[0036] In the control device for an electric vehicle according to the embodiment of the present invention, in the range switching operation equivalent to the above-mentioned sequential shift, a switching operation for switching from a currently selected range to another range that is two or more steps different, or a range switching operation equivalent to a jump shift operation in a "shift device" for a manual transmission vehicle, is defined as a continuous switching operation. Then, as described later, when the above-mentioned continuous switching operation is performed, the control device for an electric vehicle according to the embodiment of the present invention is configured to determine whether or not the actual range can be switched based on the required drive torque that is scheduled to be set in the range to be switched to by the continuous switching operation.

[0037] The detection unit 3 is a device or apparatus for acquiring various data and information required for controlling the vehicle Ve, and includes, for example, a power supply unit, a microcomputer, a sensor, and an input / output interface. In particular, the detection unit 3 in the embodiment of the present invention detects the running state of the vehicle Ve, the operating state of the motor 1, the operating state of the shift device 2, and the like, and detects various data for controlling the motor 1. Specifically, the detection unit 3 includes a vehicle speed sensor 3a for detecting the vehicle speed, an accelerator pedal sensor 3b for detecting the amount of operation of the accelerator pedal by the driver (depression amount, depression angle, etc.), a shift position sensor 3c for detecting the operation position of the shift device 2 by the driver, and a motor rotation speed sensor (or resolver) 3d for detecting the rotation speed of the motor 1. In addition, the detection unit 3 includes, for example, an SOC sensor 3e for detecting the state of charge (SOC) of a battery (not shown), a battery temperature sensor 3f for detecting the temperature of the battery, and the like. The detection unit 3 is electrically connected to a controller 4 described later, and outputs an electrical signal corresponding to the detected values ​​or calculated values ​​of the various sensors, devices, and apparatuses described above to the controller 4 as detection data.

[0038] The controller 4 is an electronic control device mainly composed of, for example, a microcomputer, and the controller 4 in the embodiment of the present invention controls the vehicle Ve and in particular controls the output torque of the motor 1 as a driving force source. Various data detected or calculated by the above-mentioned detection unit 3 are input to the controller 4. The controller 4 performs calculations using the input various data and pre-stored data, calculation formulas, etc. Then, the controller 4 is configured to output the calculation results as a control command signal and control the output torque of the motor 1 as described above. Note that, although an example in which one controller 4 is provided is shown in FIG. 1, a plurality of controllers 4 may be provided for each device or equipment to be controlled, or for each control content.

[0039] As described above, the control device for an electric vehicle in the embodiment of the present invention is configured to allow the driver to experience the same sensation of shifting gears as with conventional manual operations without compromising the stability and operability of the vehicle Ve. An example of the control executed by the controller 4 for this purpose is shown in the flowchart of FIG.

[0040] The control shown in the flowchart of FIG. 8 is executed when the vehicle Ve is traveling. As described above, the vehicle Ve in the embodiment of the present invention is configured to enable a simulated experience of a gear shift operation of a conventional vehicle equipped with a transmission. For example, the vehicle Ve may be configured to selectively set a manual mode that enables a simulated gear shift operation using the manual operation unit 2a of the shift device 2 and a normal mode in which the vehicle is driven and operated as a general electric vehicle. In this case, the control shown in the flowchart of FIG. 8 is executed when the vehicle Ve is traveling with the manual mode selected.

[0041] In the flowchart of FIG. 8, first, in step S1, it is determined whether or not a DOWN switch signal has been input. The DOWN switch signal is a signal that is turned ON and input to the controller 4 when the manual operation unit 2a is operated. For example, it is a signal that is input to the controller 4 when the above-mentioned shift switch (- switch) 2f or the paddle switch (DOWN switch) 2h is operated once. Specifically, when the shift switch 2f or the paddle switch 2h is operated for a period of time Ts1 or more shown as the period from time t1 to time t2 in the time chart of FIG. 9, it is determined that a DOWN switch signal has been input. The time Ts1 is a time for confirming that the shift switch 2f or the paddle switch 2h has been operated.

[0042] If the DOWN switch signal has not yet been input and therefore the answer is "No" in step S1, the routine shown in the flowchart of FIG. 8 is temporarily terminated without executing the controls in the subsequent steps.

[0043] On the other hand, if a DOWN switch signal has been input and therefore "Yes" is determined in step S1, the process proceeds to step S2.

[0044] In step S2, a downrange is performed. A downrange is a change from the currently selected range to a range in which the required drive torque increases. In the example shown in the time chart of FIG. 9, after time t2 when the input of the DOWN switch signal is confirmed, a change from the currently selected "D range" to "3 range" where the required drive torque is one step higher is performed.

[0045] Next, in step S3, it is determined whether or not a continuous DOWN switch signal is input. The continuous DOWN switch signal is a signal in which the above-mentioned DOWN switch signal is continuous, and is a signal for determining whether or not a continuous switching operation has occurred in the embodiment of the present invention. Specifically, when the shift switch 2f or the paddle switch 2h is operated again for a time period Ts2 indicated by the period from time t5 to time t6 after the operation of the shift switch 2f or the paddle switch 2h has been turned OFF for a time period Ti indicated by the period from time t3 to time t4 in the time chart of FIG. 9, it is determined that a continuous DOWN switch signal has been input. That is, it is determined that a continuous range switching operation has been performed by the driver. The time Ti is a time for confirming that the operation of the shift switch 2f or the paddle switch 2h has been turned OFF. Moreover, the time Ts2 is a time for confirming that the shift switch 2f or the paddle switch 2h has been operated again as described above.

[0046] Note that the continuous range switching operation by the driver may be determined to have occurred when the shift switch 2f or the paddle switch 2h is operated continuously for a predetermined period of time or more. For example, in the example shown in the time chart of Fig. 9, when the operation of the shift switch 2f or the paddle switch 2h is continued for a period of time from time t1 to time t6 (i.e., the total time of time Ts1, time Ti, and time Ts2) or more, it is determined to have occurred.

[0047] If the continuous DOWN switch signal has not yet been input and therefore the answer is "No" in step S3, the routine shown in the flowchart of FIG. 8 is temporarily terminated without executing the controls of the subsequent steps.

[0048] On the other hand, if a continuous DOWN switch signal has been input, that is, if the driver has performed a continuous range switching operation and therefore the answer is "Yes" in step S3, the process proceeds to step S4.

[0049] As described above, when using the shift device 2 simulating a "shift device" for a conventional MT vehicle, a range switching operation equivalent to a so-called jump shift operation, such as switching from a range equivalent to a 6th gear position to a range equivalent to a 4th gear position, is considered to be a continuous switching operation. Therefore, in the above step S3, when a range switching operation equivalent to the above-mentioned jump shift operation is performed in the shift device 2 simulating a "shift device" for a conventional MT vehicle, it is determined that a continuous DOWN switch signal has been input.

[0050] In step S4, it is determined whether the continuous DOWN switch signal is within an allowable range. In other words, it is determined whether the continuous DOWN switch signal is acceptable. Specifically, it is determined whether or not to allow the actual switching of the range by the continuous switching operation based on the required driving torque (control target value) to be set in the range to be switched to. For example, as shown in FIG. 10, a torque threshold is set as a threshold for determining whether or not the continuous switching operation is acceptable. Then, when the required driving torque to be set in the range to be switched to (the range to be switched to) by the continuous switching operation as described above is equal to or less than the torque threshold, the switching of the range is permitted. When the required driving torque to be set in the range to be switched to is greater than the torque threshold, the switching of the range is rejected (not permitted). In other words, when the required driving torque to be set in the range to be switched to is within a switching permission determination region set in consideration of the vehicle speed or the number of revolutions of the motor 1, the actual switching of the range by the continuous switching operation is permitted.

[0051] In this case, the torque threshold is preset corresponding to the vehicle speed or the rotation speed of the motor 1, for example, based on the results of a driving experiment using an actual vehicle or a simulation. Specifically, as shown in FIG. 10, the torque threshold is set to be larger as the vehicle speed decreases. Note that when the motor 1 outputs driving torque as a driving force source for the vehicle Ve, the rotation speed increases or decreases depending on the vehicle speed. Therefore, the torque threshold can be set as described above using either the vehicle speed or the rotation speed of the motor 1 as a parameter.

[0052] In addition, in the embodiment of the present invention, instead of the torque threshold value as described above, a torque step threshold value can be used to determine whether or not a continuous switching operation is possible. For example, as shown in FIG. 11, a torque step threshold value is set as a threshold value for determining whether or not a continuous switching operation is possible. Then, when the increase rate (so-called torque step) of the required driving torque to be set in the range to be switched to (the switching destination) by the continuous switching operation as described above with respect to the current required driving torque is equal to or less than the torque step threshold value, the switching of the range is permitted. When the increase rate of the required driving torque to be set in the switching destination range is greater than the torque step threshold value, the switching of the range is rejected (not permitted). In other words, when the increase rate of the required driving torque to be set in the switching destination range is within a switching permission determination region set in consideration of the vehicle speed or the rotation speed of the motor 1, the actual switching of the range by the continuous switching operation is permitted.

[0053] In this case, the torque step threshold is also set in advance based on, for example, the results of a running experiment using an actual vehicle or a simulation, corresponding to the vehicle speed or the rotation speed of the motor 1. Specifically, as shown in Fig. 11, the torque step threshold is set to be larger as the vehicle speed is lower.

[0054] The torque threshold or torque step threshold as described above may be changed according to the driving mode of the vehicle Ve. For example, if the vehicle Ve is configured to be able to selectively set a sports mode in addition to a standard driving mode (normal mode), the torque threshold or torque step threshold may be made larger in the sports mode compared to the normal mode. That is, the switching permission determination region as described above may be expanded. The sports mode is a driving mode that enables the vehicle Ve to travel with more dynamic acceleration characteristics compared to the normal mode. Therefore, in the sports mode, the torque threshold or torque step threshold is set to a larger value as described above, with emphasis placed on improving the operability, power performance, and driving performance of the vehicle Ve rather than the comfort and stability of the vehicle Ve. By increasing the torque threshold or torque step threshold and expanding the switching permission determination region, the range switching becomes more likely to be permitted. Therefore, even when the vehicle Ve travels in a situation where the required driving torque is large, the range switching by the continuous switching operation becomes more likely to be performed, and the operability of the vehicle Ve is improved.

[0055] If the continuous DOWN switch signal is within the permitted range, that is, if the determination in step S4 is "Yes" because actual switching of the range by the continuous switching operation is permitted, the process proceeds to step S5.

[0056] In step S5, further down-range, that is, so-called range jumping, is performed. In this case, the range jumping is a switch from the currently selected range to a range in which the required drive torque is increased by two or more steps. In the example shown in the time chart of FIG. 9, acceptance of a continuous DOWN switch signal is permitted at time t6, and after time t6, the currently selected "D range" is switched to "2 range" where the required drive torque is increased by two steps, skipping "3 range".

[0057] Next, in step S5, it is determined whether or not a continuous DOWN switch signal has been input, as in the previous step S3. If the continuous DOWN switch signal has been input, that is, if the driver has performed another continuous range switching operation and the determination is "Yes" in this step S3, the process returns to step S4 and the same control as before is executed.

[0058] On the other hand, if there is no input of the continuous DOWN switch signal and therefore the determination in step S5 is "No," the routine shown in the flowchart of FIG. 8 is temporarily ended without executing the subsequent control.

[0059] On the other hand, if the continuous DOWN switch signal is outside the permitted range, that is, if the actual range switching by the continuous switching operation is rejected and the result is "No" in the above step S4, the process proceeds to step S7.

[0060] In step S7, the continuous DOWN switch signal is not accepted. That is, the refusal of range switching by continuous switching operation is confirmed. In the example shown in the time chart of FIG. 9, the continuous DOWN switch signal is not accepted at time t6, and after time t6, switching from the currently selected "D range" to "2 range" (range jump) is not performed, but the range is switched to "3 range" where the required drive torque is increased by one step. After that, the routine shown in the flowchart of FIG. 8 is temporarily terminated.

[0061] In this way, in the control device for an electric vehicle according to the embodiment of the present invention, when the driver performs a continuous switching operation of the shift device 2, it is determined whether or not to permit the actual switching of the range by the continuous switching operation. For example, when the required drive torque set in the switching destination range is greater than the torque threshold value, or when the increase rate of the required drive torque set in the switching destination range relative to the current required drive torque is greater than the torque step threshold value, it is determined that the behavior of the vehicle Ve may be disturbed, and the switching of the range by the continuous switching operation is rejected. When the required drive torque set in the switching destination range is equal to or less than the torque threshold value, or when the increase rate of the required drive torque set in the switching destination range relative to the current required drive torque is equal to or less than the torque step threshold value, it is determined that there is no possibility that the behavior of the vehicle Ve may be disturbed, and the switching of the range by the continuous switching operation is permitted. Therefore, the actual switching of the range by the continuous switching operation is appropriately performed in a stable state where there is no risk of disturbing the behavior of the vehicle Ve. Then, the range switching operation using the shift device 2 as described above can simulate the shifting operation of a vehicle equipped with a transmission.

[0062] Therefore, according to the control device for an electric vehicle in the embodiment of the present invention, the driver can appropriately experience an operating feel similar to that of a conventional vehicle equipped with a transmission, without compromising either the operability or stability of the vehicle Ve. [Explanation of symbols]

[0063] 1. Motor (driving force source) 2 Shifting device 2a Manual operation part (of shifting device) 2b (Manual operation part) Shift lever 2c, 2d (Manual operation part) shift gate 2e, 2f (Manual operation section) Shift switch 2g,2h (Manual operation section) Paddle switch 3. Detection section 3a (Detection section) Vehicle speed sensor 3b (Detection section) Accelerator pedal sensor 3c (detection part) shift position sensor 3d (Detection section) Motor speed sensor (or resolver) 3e SOC sensor (detection section) 3f (Detection section) Battery temperature sensor 4 Controller (ECU) 5 Differential gear 6 Drive wheels (front wheels) 7 Rear wheel 8. Steering Wheel 8a (Steering wheel) spokes Ve vehicle (electric vehicle)

Claims

1. A control device for an electric vehicle that includes at least a motor as a driving force source, and controls the motor based on a control target value that is set corresponding to a required driving force, the control target value is set in a plurality of ranges in which torque characteristics with respect to the rotation speed of the motor are gradually different, a shift device for selecting one of the plurality of ranges in response to a manual operation by a driver; a controller that controls an output torque of the motor based on the control target value that is set according to the range selected by the shift device, The controller: When a continuous switching operation is performed to switch to another range that is two or more steps different from the range currently selected by the shift device, it is determined whether or not the range can be switched by the continuous switching operation based on the control target value set in the range to be switched to. A control device for an electric vehicle.

2. The control device for an electric vehicle according to claim 1, The continuous switching operation is an operation for switching to a range in a direction in which the control target value is larger than that of the currently selected range. A control device for an electric vehicle.

3. The control device for an electric vehicle according to claim 1 or 2, The controller: When the continuous switching operation is performed, if the control target value set in the switching destination range is equal to or less than a torque threshold value for determining whether or not the continuous switching operation is possible, the switching of the range is permitted; If the control target value set in the range to be switched to is greater than the torque threshold value, the range switching is rejected. A control device for an electric vehicle.

4. The control device for an electric vehicle according to claim 3, The torque threshold value varies depending on a vehicle speed or the rotation speed, The controller: permitting the range to be switched when the control target value set in the range to be switched to is equal to or less than the torque threshold value corresponding to the vehicle speed or the rotation speed when the continuous switching operation is performed; When the control target value set in the range to be switched to is greater than the torque threshold value corresponding to the vehicle speed or the rotation speed when the continuous switching operation is performed, the switching of the range is rejected. A control device for an electric vehicle.

5. The control device for an electric vehicle according to claim 4, The torque threshold value increases as the vehicle speed or the rotation speed decreases. A control device for an electric vehicle.

6. The control device for an electric vehicle according to claim 1 or 2, The controller: When the continuous switching operation is performed, if an increase rate of the control target value set in the range to be switched to with respect to the current control target value is equal to or less than a torque step threshold value for determining whether or not the continuous switching operation is possible, the switching of the range is permitted; If the increase rate is greater than the torque step threshold, the range change is rejected. A control device for an electric vehicle.

7. The control device for an electric vehicle according to claim 6, The torque step threshold varies depending on the vehicle speed or the rotation speed, The controller: permitting the range switching when the rate of increase is equal to or less than the torque step threshold value corresponding to the vehicle speed or the rotational speed when the continuous switching operation is performed; If the rate of increase is greater than the torque step threshold value corresponding to the vehicle speed or the rotational speed when the continuous switching operation is performed, the range switching is rejected. A control device for an electric vehicle.

8. The control device for an electric vehicle according to claim 7, The torque step threshold value increases as the vehicle speed or the rotation speed decreases. A control device for an electric vehicle.

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