Control device for electric vehicle

Abstract

The invention provides an electric vehicle which can enable a driver to appropriately experience the same operation feeling as that of a conventional vehicle equipped with a transmission without reducing the stability and operability of the vehicle. In a control device for an electric vehicle using a motor as a driving force source, a required driving torque is set by dividing into a plurality of different stages with respect to torque characteristics of a rotational speed (or vehicle speed) of the motor, and an output torque of the motor is controlled on the basis of the required driving torque set in accordance with a stage selected by a shift device. When a continuous switching operation for switching from the selected range to another two or more different ranges is performed, it is determined whether or not the actual range can be switched by the continuous switching operation of the ranges on the basis of the required drive torque set in the range of the target to be switched (step S4).

Description

Technical Field

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

[0002] Patent document 1 describes an electric vehicle (electric vehicle) for the purpose of simulating the speed change action of a vehicle equipped with a manual transmission (MT vehicle). The electric vehicle described in patent document 1 is provided with a shift device and a clutch device operated by a driver. The shift device and the clutch device are respectively simulated devices that assume the devices installed on the MT vehicle, and the clutch device is operated in association with the driver's operation of the shift device. In addition, the electric vehicle described in patent document 1 is provided with a torque control unit that controls the output torque of the motor of the driving force source. The torque control unit controls the output torque of the motor according to the operation amount of the clutch device. At the same time, the shift device is configured to select any one mode from a plurality of modes (or gears) with different levels of torque characteristics relative to the rotational speed of the motor, and the torque control unit controls the output torque of the motor according to the mode selected by the shift device.

[0003] In addition, Patent Document 2 describes an electric vehicle that aims to give the driver a feeling of driving a manual transmission vehicle (MT vehicle). The electric vehicle described in Patent Document 2 has 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) indicated to the motor, and a control device that sets the torque map. The torque map is set according to each virtual transmission level corresponding to a plurality of shift positions. Moreover, the control device uses the torque map of the virtual gear level corresponding to the shift position selected by the shift lever to determine the torque value and control the output torque of the motor.

[0004] In addition, the electric vehicle described in Patent Document 3 is equipped with a paddle switch and a shift mechanism (shift lever, etc.) electrically connected to an ECU (control device). The ECU uses a torque map that specifies the relationship between the opening of the accelerator pedal and the output torque of the motor to control the output torque of the motor according to the opening of the accelerator pedal. At the same time, the ECU changes the torque map used for controlling the output torque of the motor based on the driver's operation of the paddle switch or the shift mechanism.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-118569

[0006] Patent Document 2: Japanese Patent Application Publication No. 2020-156260

[0007] Patent Document 3: Japanese Patent Application Publication No. 2022-12205

[0008] The motor mounted on the electric vehicle as a driving force source can output a large torque from the start and when driving at low speed. Therefore, there are also electric vehicles that do not carry a transmission for amplifying the driving torque. The electric vehicles described in the above-mentioned patent documents are not equipped with an actual transmission, but are provided with a shift device, a shift switch, etc. that are the same as before. At the same time, multiple modes or torque mappings are set to make the torque characteristics of the motor different. Moreover, in the electric vehicles described in the above-mentioned patent documents, these modes or torque mappings are switched by the manual operation of the driver using a shift device, a shift switch, etc., thereby virtualizing the same transmission as before. Therefore, according to the electric vehicles described in Patent Documents 1 and 2, the driver can experience the same driving operation feeling and vehicle behavior as the MT vehicle equipped with a manual transmission in the past. In addition, according to the electric vehicle described in Patent Document 3, the driver can experience the same feeling of manual shifting operation (sequential shifting) using a paddle switch, a shift lever, etc. as the vehicle equipped with a multi-stage transmission in the past.

[0009] However, in the case of setting multiple modes or torque mapping to control the output torque of the motor as in the electric vehicles described in the above-mentioned patent documents, there is a concern that the stability of the electric vehicle is reduced. For example, if a switching operation to two or more different modes (or gears) or a continuous switching operation across gears is performed in a short period of time, and the torque characteristics of the motor are switched corresponding to such an operation, the output torque of the motor changes sharply. That is, the driving force of the electric vehicle changes sharply. In particular, if the mode is switched in the direction equivalent to the downshift in the previous transmission, the driving force increases sharply, and as a result, there is a concern that the tires slip and the behavior of the electric vehicle is disordered. In order to avoid such a sharp change in the driving force of the electric vehicle, it is also possible to consider prohibiting the above-mentioned switching operation to two or more different modes and the continuous switching operation across gears. However, in this case, part of the switching operation that can be performed by the previous vehicle equipped with a transmission is limited. Therefore, compared with the previous vehicle equipped with a transmission, the operability of the electric vehicle is reduced.

[0010] Thus, there is still room for improvement in order to construct an electric vehicle that allows the driver to experience the same feeling of shifting operation as in the past without causing a decrease in the operability of the vehicle and a decrease in the stability of the vehicle behavior. Summary of the invention

[0011] The present invention has been made in view of the above technical problems, and an object of the present invention is to provide an electric vehicle that allows a driver to appropriately experience the same operating feeling as a conventional vehicle equipped with a transmission without reducing the operability and stability of the vehicle.

[0012] In order to achieve the above-mentioned purpose, the present invention is a control device for an electric vehicle that has at least a motor as a driving force source and controls the above-mentioned motor based on a control target value set corresponding to the required driving force. It is characterized in that the above-mentioned control target value is set to a plurality of gears with different levels of torque characteristics relative to the rotational speed of the above-mentioned motor, and comprises: a shifting device that selects any one of the above-mentioned multiple gears according to the manual operation of the driver; and a controller that controls the output torque of the above-mentioned motor based on the above-mentioned control target value set according to the above-mentioned gear selected by the above-mentioned shifting device. When a continuous switching operation for switching from the currently selected gear to another different gear of more than two levels is performed by the above-mentioned shifting device, the above-mentioned controller determines whether the above-mentioned gear can be switched through the above-mentioned continuous switching operation based on the above-mentioned control target value set at the above-mentioned gear of the switching target.

[0013] Alternatively, the continuous switching operation in the present invention is an operation for switching the gear in a direction in which the control target value becomes larger than that of the currently selected gear (i.e., a direction in which the output torque corresponding to the rotational speed of the motor becomes larger).

[0014] In addition, the controller in the present invention may also be configured as follows: when the above-mentioned continuous switching operation is performed, when the above-mentioned control target value set at the above-mentioned gear of the switching target is below the torque threshold for determining whether the above-mentioned continuous switching operation can be performed, the switching of the above-mentioned gear is permitted; and when the above-mentioned control target value set at the above-mentioned gear of the switching target is greater than the above-mentioned torque threshold, the switching of the above-mentioned gear is rejected.

[0015] In addition, it can also be constructed as follows: the above-mentioned torque threshold in the present invention is a setting that changes according to the vehicle speed or the above-mentioned rotational speed. When the above-mentioned control target value set in the above-mentioned gear of the switching target is lower than the above-mentioned torque threshold corresponding to the above-mentioned vehicle speed or the above-mentioned rotational speed when the above-mentioned continuous switching operation is performed, the above-mentioned controller in the present invention permits the switching of the above-mentioned gear; when the above-mentioned control target value set in the above-mentioned gear of the switching target is greater than the above-mentioned torque threshold corresponding to the above-mentioned vehicle speed or the above-mentioned rotational speed when the above-mentioned continuous switching operation is performed, the above-mentioned controller rejects the switching of the above-mentioned gear.

[0016] Furthermore, the torque threshold value in the present invention may be set to be larger as the vehicle speed or the rotation speed is lower.

[0017] In addition, it can also be constructed as follows: when the above-mentioned continuous switching operation is performed, when the increase ratio of the above-mentioned control target value set at the above-mentioned gear of the switching target relative to the current above-mentioned control target value is below the torque step difference threshold for determining whether the above-mentioned continuous switching operation can be performed, the above-mentioned controller in the present invention allows the switching of the above-mentioned gear; when the above-mentioned increase ratio is greater than the above-mentioned torque step difference threshold, the above-mentioned controller refuses to switch the above-mentioned gear.

[0018] In addition, it can also be constructed as follows: the above-mentioned torque step difference threshold in the present invention is a setting that changes according to the vehicle speed or the above-mentioned rotational speed. When the above-mentioned increase ratio is lower than the above-mentioned torque step difference threshold corresponding to the above-mentioned vehicle speed or the above-mentioned rotational speed when the above-mentioned continuous switching operation is performed, the above-mentioned controller in the present invention allows the above-mentioned gear switching; when the above-mentioned increase ratio is greater than the above-mentioned torque step difference threshold corresponding to the above-mentioned vehicle speed or the above-mentioned rotational speed when the above-mentioned continuous switching operation is performed, the above-mentioned controller refuses the above-mentioned gear switching.

[0019] Furthermore, the torque step difference threshold value in the present invention may be set to be larger as the vehicle speed or the rotation speed is lower.

[0020] The electric vehicle that is the object of control in the present invention uses at least one motor as a driving force source, and generates driving force and travels by the output torque of the motor. The output torque of the motor is controlled based on the control target value set corresponding to the required driving force. In other words, the control target value is the target driving torque, or the required driving torque, which is set, for example, in the form of a mapping and divided into a plurality of gears with different levels of torque characteristics of the motor. These multiple gears are selectively set by a shift device manually operated by the driver. Therefore, in the control device of the electric vehicle of the present invention, the gear is switched by the shift device, thereby changing the torque characteristics of the motor and the control target value set based on its torque characteristics. For example, it is possible to switch from a gear with a standard torque characteristic to a gear with a torque characteristic that outputs a larger torque at a low speed. Therefore, even an electric vehicle that does not use a transmission can enable the driver to experience the same feeling of shifting operation as previous vehicles equipped with a manual transmission or a multi-stage transmission.

[0021] Furthermore, in the control device of the electric vehicle of the present invention, when the driver performs a continuous switching operation on the gear shift device, it is determined whether the actual switching of the gear position performed by the continuous switching operation is permitted. The continuous switching operation is an operation of switching from the currently selected gear position to another gear position of two or more different gear positions through the gear shift device, for example, an operation of switching to another discontinuous gear position by skipping another continuous gear position during a specified short period of time, or an operation of switching to another gear position by crossing another adjacent gear position. If the gear position is switched by such a continuous switching operation, the torque characteristics of the motor are greatly changed, and therefore the driving force generated by the output torque of the motor also changes greatly. As a result, there is a concern that the electric vehicle may be disturbed due to impact and tire slip. Therefore, in the control device of the electric vehicle of the present invention, when the continuous switching operation of the gear shift device is performed, it is determined whether the gear position can be switched by the continuous switching operation based on the predetermined control target value set in the gear position of the switching target. For example, when the control target value set at the gear of the switching target is greater than a prescribed threshold value (torque threshold), or when the increase ratio of the control target value set at the gear of the switching target relative to the current control target value is greater than a prescribed threshold value (torque step difference threshold), it is determined that there is a possibility of disordered behavior of the electric vehicle, and the gear switching based on the continuous switching operation is rejected. When the control target value set at the gear of the switching target is below the torque threshold, or when the increase ratio of the control target value set at the gear of the switching target relative to the current control target value is below the torque step difference threshold, it is determined that there is no possibility of disordered behavior of the electric vehicle, and the gear switching based on the continuous switching operation is permitted. Therefore, the actual switching of the gear based on the continuous switching operation is appropriately implemented in a stable state without the concern of disordered behavior of the electric vehicle. Moreover, by using the gear switching operation of the shifting device as described above, the speed change operation of a vehicle equipped with a transmission can be simulated and reproduced.

[0022] Therefore, according to the control device for an electric vehicle of the present invention, it is possible to allow the driver to appropriately experience the same operating feeling as that of a conventional vehicle equipped with a transmission without degrading both the operability and the stability of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a block diagram schematically showing the structure (drive system and control system) of an electric vehicle that is a control target in the present invention.

[0024] Figure 2 This is a diagram showing torque characteristics of a general motor.

[0025] Figure 3This is a diagram showing an image of a map for calculating the required driving torque of the motor corresponding to the vehicle speed (or the rotation speed of the motor) and the operation amount of the accelerator pedal.

[0026] Figure 4 This is a diagram showing an image of a map for calculating the required driving torque corresponding to a case where the operation amount of the accelerator pedal is 50%.

[0027] Figure 5 This is a diagram showing an image of a shift device having a manual operation portion composed of a shift lever and a shift gate.

[0028] Figure 6 This is a diagram showing an image of a shift device having a manual operation portion provided on a steering wheel. Figure 6 (a) is a diagram showing a shift switch provided on a steering wheel. Figure 6 (b) is a diagram showing a paddle switch provided on a steering wheel.

[0029] Figure 7 This is a diagram showing an image of a shift position switching operation performed by a shift device having a manual operation unit (equivalent to sequential shifting).

[0030] Figure 8 This is a flowchart for explaining an example of control executed by the control device for the electric vehicle of the present invention.

[0031] Fig. 9 It means that it is executed Figure 8 A timing diagram of the switching state of the gear position in the case of the control shown in the flowchart.

[0032] Fig.10 It means executing Figure 8 FIG. 1 is an image of a torque threshold used in a control case shown in a flowchart.

[0033] Fig.11 It means executing Figure 8 FIG. 1 is an image of a torque step difference threshold used in a control case shown in a flowchart.

[0034] Description of Reference Numerals

[0035] 1…motor (driving force source); 2…shift device; 2a…manual operation part (of shift device); 2b…shift lever (of manual operation part); 2c, 2d…shift slot (of manual operation part); 2e, 2f…shift switch (of manual operation part); 2g, 2h…paddle switch (of manual operation part); 3…detection part; 3a…vehicle speed sensor (of detection part); 3b…accelerator pedal sensor (of detection part); 3c…shift position sensor (of detection part); 3d…motor speed sensor (or resolver) (of detection part); 3e…SOC sensor (of detection part); 3f…battery temperature sensor (of detection part); 4…controller (ECU); 5…differential gear; 6…drive wheel (front wheel); 7…rear wheel; 8…steering wheel; 8a…spoke part (of steering wheel); Ve…vehicle (electric vehicle). DETAILED DESCRIPTION

[0036] Embodiments of the present invention will be described with reference to the drawings. The embodiments described below are merely examples of specific embodiments of the present invention and do not limit the present invention.

[0037] exist Figure 1 2 schematically shows an example of a drive system and a control system of an electric vehicle that is a control target in an embodiment of the present invention. Figure 1 The electric vehicle (hereinafter referred to as vehicle) Ve shown is an electric vehicle equipped with a motor (Motor) 1 as a driving force source. In addition, the vehicle Ve includes a shift device 2, a detection unit 3, and a controller (ECU) 4.

[0038] In addition, the vehicle Ve that is the control target in the embodiment of the present invention may also have one or more motors (not shown) as a driving force source in addition to the motor 1. Alternatively, it may be a "hybrid vehicle" that uses the motor 1 and an engine (not shown) as a driving force source. Figure 1 As shown, the vehicle Ve may be a front-wheel drive vehicle that transmits the output torque of the motor 1 to the front wheel (drive wheel) 6, for example, via a speed reduction mechanism (not shown), a differential gear 5, etc., and generates a driving force on the front wheel 6. Alternatively, the vehicle Ve may be a rear-wheel drive vehicle (not shown) that transmits the output torque of the motor 1 to the rear wheel 7, for example, via a transmission shaft (not shown), etc., and generates a driving force on the rear wheel 7. Alternatively, the vehicle Ve may be a four-wheel drive vehicle (not shown) that is provided with a transfer mechanism (not shown) to transmit the output torque of the motor 1 to both the front wheel 6 and the rear wheel 7, and generates a driving force on both the front wheel 6 and the rear wheel 7.

[0039] The motor 1 is composed of, for example, a permanent magnet synchronous motor or an induction motor. The motor 1 has at least the function of being a prime mover that is driven by being supplied with electric power and outputs torque. In addition, the motor 1 can also function as a generator that is driven by receiving torque from the outside and then generates electric power. That is, the motor 1 can also be a so-called electric generator that has both the function of a prime mover and the function of a generator. A battery (not shown) is connected to the motor 1 via an inverter (not shown). Therefore, the power stored in the battery can be supplied to the motor 1, so that the motor 1 functions as a prime mover to output driving torque. In addition, the motor 1 can also function as a generator with the help of the torque transmitted from the drive wheel 6, and the regenerative power generated at this time is stored in the battery. Moreover, the motor 1 is electrically controlled to output the speed and torque by the controller 4 described later. For example, the required driving force is calculated according to the amount of operation of the accelerator pedal (not shown) by the driver and the vehicle speed, and the output torque of the motor 1 is controlled based on the required driving torque (that is, the control target value of the motor 1) set corresponding to the required driving force. As described later, the required driving torque is set in a plurality of gears with different torque characteristics of the motor 1, for example, by mapping. Then, any gear is selected by the shift device 2 described later, and the required driving torque corresponding to the selected gear is set.

[0040] like Figure 2 As shown, the motor 1 has a unique torque characteristic. Figure 2 In FIG. 1 , the torque characteristics of the motor 1 are shown by setting the vertical axis as the required driving torque and the horizontal axis as the vehicle speed. If the transmission ratio between the motor 1 and the drive wheel 6 is taken into consideration, the vehicle speed on the horizontal axis can also be considered as the rotation speed of the motor 1. Figure 2 The solid line shows the torque characteristics when the output of the motor 1 is limited, and the dotted line shows the torque characteristics when there is no output limitation on the motor 1. The output limitation of the motor 1 is used, for example, to reduce the load on the motor 1 in order to protect the motor 1 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, for example, when the SOC of the battery is low or the temperature of the battery is low, by limiting the discharge of the battery, the motor 1 becomes in the same state as when the output limitation as described above is applied.

[0041] In addition, the motor 1 is based on, for example, Figure 3 The required driving torque is set according to the map shown. Figure 3 The mapping shown shows the Figure 2 The torque characteristics of the motor 1 shown in FIG. 1 are the required driving torque corresponding to the vehicle speed (or the rotation speed of the motor 1) and the amount of operation of the accelerator pedal. Figure 3The required driving torque calculated when the gear position of the required driving torque described later is the "D range" (standard driving range) is shown.

[0042] The required driving torque of the motor 1 is, for example, Figure 4 The mapping method shown is set to be divided into a plurality of gears with different torque characteristics of the motor 1 . Figure 4 For example, a plurality of gears corresponding to the required drive torque when the accelerator pedal operation amount is 50% are shown. Figure 4 In the example shown, the required driving torques set in "D gear", "3rd gear", "2nd gear", and "L gear (1st gear)" are shown in order from the bottom. "D gear" is a gear for setting a standard required driving torque during normal driving. "3rd gear" is a gear for setting a required driving torque that is one level higher than "D gear". "2nd gear" is a gear for setting a required driving torque that is one level higher than "3rd gear". Moreover, "L gear" is a gear for setting a required driving torque that is one level higher than "2nd gear".

[0043] In summary, in the electric vehicle control device according to the embodiment of the present invention, in order to calculate the control target value when controlling the output torque of the motor 2, that is, the required driving torque, the above-mentioned Figure 3 , Figure 4 The mapping shown is the driving torque mapping. The driving torque mapping is a mapping that sets the torque characteristics of the motor 2 relative to the vehicle speed (or the rotation speed of the motor 2). Moreover, the driving torque mapping with different levels of torque characteristics of the motor 2 as described above is set in a plurality of gears according to the operation amount of the accelerator pedal (the driving force required by the driver).

[0044] The shift device 2 is manually operated by the driver to select any one gear from the gears of the torque characteristics of the motor 1 set in multiple stages as described above. That is, a drive torque map corresponding to any one gear is selected from the drive torque map set in multiple gears. The vehicle Ve in the embodiment of the present invention is not actually equipped with a transmission as provided in previous engine vehicles. Therefore, the vehicle Ve does not originally need a "shift device" for performing a speed shift operation of the transmission. The shift device 2, the gears of the torque characteristics divided into multiple stages as described above, and the drive torque map are not actual structures for performing a speed shift operation of the transmission, but are configured to simulate the manual operation in previous vehicles equipped with a manual transmission or a multi-stage transmission and the behavior of the vehicle, so that even if it is an electric vehicle Ve, the driver can experience the feeling of speed shifting based on manual operation.

[0045] Specifically, the shift device 2 has a manual operation unit 2a. The manual operation unit 2a is operated according to the manual operation of the driver to select any one of the multiple stages of the gear. The shift device 2 outputs a switch signal corresponding to the gear selected by the manual operation unit 2a. The switch signal is sent to the controller 4 described later.

[0046] The manual operation unit 2a is composed of, for example, Figure 5 The shift lever 2b and the shift gates 2c and 2d are configured as shown. Figure 5 The shift device 2 shown has the same structure as a conventional "shift device" used in a vehicle equipped with a conventional automatic transmission (multi-speed transmission). Figure 5 In the shift groove 2c shown on the left side of the vehicle, by moving the shift lever 2b, any one of the "driving (D) gear", "reverse (R) gear" and "parking (P) gear" is selected. Figure 5 The shift lever 2b is moved upward (+) to the shift groove 2d shown on the right side of the figure, thereby changing the gear position by one level in the direction in which the required driving torque decreases. That is, the gear position switching is performed in the same manner as the upshift in the conventional transmission. On the other hand, the shift lever 2b is moved downward (-) to change the gear position by one level in the direction in which the required driving torque increases. That is, the gear position switching is performed in the same manner as the downshift in the conventional transmission.

[0047] In addition, the manual operation unit 2a is composed of, for example, Figure 6 As shown, the shift switches 2e and 2f provided on the steering wheel 8, or the paddle switches 2g and 2h provided on the steering wheel 8 are configured. Figure 6 The shift device 2 shown has the same structure as a conventional “shift switch” or a conventional “paddle switch” used in a vehicle equipped with a conventional automatic transmission (multi-speed transmission). Figure 6 The shift switch (+ switch) 2e shown in (a) is, for example, provided on the back side of the spoke portion 8a of the steering wheel 8. By operating (activating) the shift switch 2e once, the gear is shifted to a smaller direction in which the required driving torque becomes smaller. That is, the gear is switched to a gear position equivalent to the upshift in the conventional transmission. In addition, Figure 6 The shift switch (-switch) 2f shown in (a) is provided on the surface side of the spoke portion 8a of the steering wheel 8, for example. By operating (activating) the shift switch 2f once, the gear is shifted to a direction where the required driving torque increases. That is, the gear is switched to a gear position equivalent to a downshift in a conventional transmission. Similarly, by operating Figure 6 The paddle switch (UP switch) 2g shown in (b) is operated once (activated), thereby changing the gear position by one gear in the direction in which the required driving torque decreases. That is, the gear position is switched to the upshift position in the conventional transmission. Figure 6The paddle switch (DOWN switch) 2h shown in (b) is operated once (activated), thereby shifting the gear position by one step in the direction in which the required driving torque increases. That is, the gear position is switched to a downshift in a conventional transmission.

[0048] In the case of Figure 5 , Figure 6 In the shift device 2 having the manual operation portion 2a as shown, for example, Figure 7 The gear position is switched as shown in the image. This is the same switching operation as the so-called sequential shifting when operating a conventional automatic transmission (multi-speed transmission) in manual mode. Figure 7 As shown, in the case where four gear positions of "D gear", "3rd gear", "2nd gear", and "L gear (1st gear)" are set, for example, by operating the shift switch (- switch) 2f or the paddle switch (DOWN switch) 2h once from the "D gear", the "3rd gear" in which the required driving torque is increased by one level is selected, by operating the shift switch 2f or the paddle switch 2h twice, the "2nd gear" in which the required driving torque is increased by two levels is selected, and by operating the shift switch 2f or the paddle switch 2h three times, the "L gear" in which the required driving torque is increased by three levels is selected. On the contrary, by operating the shift switch (+ switch) 2e or the paddle switch (UP switch) 2g once from the "L gear", the "2nd gear" in which the required driving torque is reduced by one level is selected, and by operating the shift switch 2e or the paddle switch 2g twice, the "3rd gear" in which the required driving torque is reduced by two levels is selected, and by operating the shift switch 2e or the paddle switch 2g three times, the "D gear" in which the required driving torque is reduced by three levels is selected.

[0049] Furthermore, the shift device 2 may be, for example, a simulated "shift device" assuming a device mounted on an MT vehicle as described in the above-mentioned Patent Document 1. In the shift device 2 assuming such a conventional "shift device" for an MT vehicle, a shift lever (not shown) is configured to operate in accordance with a shift pattern (or a shift gate) called a so-called H mode. For example, in the shift device 2 assuming a 6-speed shift, the first speed position to the sixth speed position 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 assuming such a conventional "shift device" for an MT vehicle, the driver can perform a switching operation corresponding to a so-called skip shift operation, such as switching from a gear position corresponding to the sixth speed position to a gear position corresponding to the fourth speed position. In addition, in addition to the shift device 2 assuming such a conventional "shift device" for an MT vehicle as described above, the vehicle Ve may also be provided with a simulated "clutch device" assuming a device mounted on an MT vehicle. Furthermore, the shift device 2 and the “clutch device” may be configured to be operated in a linked manner similar to the driving operation of a conventional MT vehicle.

[0050] In the control device of the electric vehicle in the embodiment of the present invention, in the gear switching operation corresponding to the above-mentioned sequential gear shifting, the switching operation for switching from the currently selected gear to another gear different by two or more steps, or the gear switching operation corresponding to the jump speed change operation in the "shift device" for MT vehicles is defined as a continuous switching operation. And, as described later, the control device of the electric vehicle in the embodiment of the present invention is configured to determine whether the actual gear switching can be performed based on the predetermined required driving torque set at the gear of the switching target of the continuous switching operation when the above-mentioned continuous switching operation is performed.

[0051] The detection unit 3 is a device or apparatus for obtaining various data and information required when 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 driving state of the vehicle Ve, the operating state of the motor 1, and the operating state of the shift device 2, respectively, 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 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), and a battery temperature sensor 3f for detecting the temperature of the battery. Moreover, the detection unit 3 is electrically connected to the controller 4 described later, and outputs an electrical signal corresponding to the detection value or calculated value of the various sensors, devices, and apparatuses described above to the controller 4 as detection data.

[0052] The controller 4 is, for example, an electronic control device mainly composed of a microcomputer. 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 uses the various input data and pre-stored data, calculation formulas, etc. to perform calculations. Moreover, the controller 4 is configured to output its calculation results as a control command signal and control the output torque of the motor 1 as described above. In addition, in Figure 1 Although an example in which one controller 4 is provided is shown, a plurality of controllers 4 may be provided for each device or equipment to be controlled or for each control content.

[0053] 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 feeling of manual gear shifting as in the past without reducing the stability and operability of the vehicle Ve. Figure 8 An example of control executed by the controller 4 is shown in the flowchart of FIG.

[0054] In this Figure 8 The control shown in the flowchart is executed when the vehicle Ve is traveling. In addition, as described above, the vehicle Ve in the embodiment of the present invention is a structure that can simulate the speed change operation of a conventional vehicle equipped with a transmission. For example, it can also be configured to selectively set a manual mode that can simulate the speed change operation using the manual operation unit 2a of the shift device 2, and a normal mode that performs driving operations as a general electric vehicle. In this case, the Figure 8The control shown in the flowchart is executed when the vehicle Ve is traveling in a state where the manual mode is selected.

[0055] exist Figure 8 In the flowchart, first, in step S1, it is determined whether there is an input of a DOWN switch signal. The DOWN switch signal is a signal that is activated 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, for example, Fig. 9 As shown in the timing chart, when the shift switch 2f or the paddle switch 2h is operated for a period of time Ts1 or more, which is represented by the period from time t1 to time t2, it is determined that the DOWN switch signal is input. Time Ts1 is a time for confirming that the shift switch 2f or the paddle switch 2h is operated.

[0056] If the determination in step S1 is "No" because the DOWN switch signal has not been input, the control of the subsequent steps is not executed and the process is temporarily terminated. Figure 8 The procedure is shown in the flowchart.

[0057] On the other hand, when the determination in step S1 is “YES” because the DOWN switch signal is input, the process proceeds to step S2 .

[0058] In step S2, downshifting is performed. Downshifting is switching from the currently selected gear to a gear in a direction where the required driving torque increases. Fig. 9 In the example shown in the timing chart of , after time t2 when the input of the DOWN switch signal is confirmed, the gear is switched from the currently selected "D gear" to the "3rd gear" where the required driving torque is increased by one step.

[0059] Next, in step S3, it is determined whether there is a continuous DOWN switch signal input. The continuous DOWN switch signal is a signal in which the DOWN switch signal described above is continuous, and is a signal used to determine whether there is a continuous switching operation in the embodiment of the present invention. Specifically, for example, Fig. 9As shown in the timing chart, after the shift switch 2f or the paddle switch 2h is turned off for more than time Ti represented by the period from time t3 to time t4, when the shift switch 2f or the paddle switch 2h is operated again for more than time Ts2 represented by the period from time t5 to time t6, it is determined that a continuous DOWN switch signal is input. In other words, it is determined that there is a continuous shift operation of the driver. Time Ti is a time for confirming that the shift switch 2f or the paddle switch 2h is turned off. In addition, time Ts2 is a time for confirming that the shift switch 2f or the paddle switch 2h is operated again as described above.

[0060] In addition, when the shift switch 2f or the paddle switch 2h is operated continuously for a predetermined time or longer, it may be determined that the driver has continuously switched the gear position. Fig. 9 In the example shown in the time diagram, when the operation of the shift switch 2f or the paddle switch 2h continues for more than the period represented by the time from time t1 to time t6 (i.e., the time obtained by summing up the time Ts1, the time Ti and the time Ts2), it is judged that there is a continuous switching operation.

[0061] If there is no continuous DOWN switch signal input and the result of the determination in step S3 is "No", the control of the subsequent steps is not performed and the process is temporarily terminated. Figure 8 The procedure is shown in the flowchart.

[0062] On the other hand, if the determination in step S3 is “YES” because there is a continuous input of the DOWN switch signal, that is, the driver has continuously switched the shift position, the process proceeds to step S4 .

[0063] Furthermore, as described above, when the shift device 2 simulating the "shift device" for a conventional MT vehicle is used, for example, a gear switching operation corresponding to a so-called skip shift operation such as switching from a gear corresponding to the sixth speed position to a gear corresponding to the fourth speed position is regarded as a continuous switching operation. Therefore, in the above-mentioned step S3, when a gear switching operation corresponding to the above-mentioned skip shift operation is performed in the shift device 2 simulating the "shift device" for a conventional MT vehicle, it is determined that there is a continuous DOWN switch signal input.

[0064] In step S4, it is determined whether the continuous DOWN switch signal is within the permitted range. In other words, it is determined whether the continuous DOWN switch signal is acceptable. Specifically, based on the predetermined required drive torque (control target value) set at the gear of the switching target, it is determined whether the actual switching of the gear based on the continuous switching operation is permitted. For example, Fig.10As shown, a torque threshold is set as a threshold for determining whether a continuous switching operation can be performed. Moreover, when the predetermined required driving torque set for the gear that is switched (the switching target) through the continuous switching operation as described above is below the torque threshold, the gear switching is permitted. When the predetermined required driving torque set for the gear of the switching target is greater than the torque threshold, the gear switching is rejected (considered as not permitted). In other words, if the predetermined required driving torque set for the gear of the switching target is within the switching permission judgment area set in consideration of the vehicle speed or the rotational speed of the motor 1, the actual switching of the gear based on the continuous switching operation is permitted.

[0065] In this case, the torque threshold is set in advance based on the results of a real vehicle driving test, simulation, etc., corresponding to the vehicle speed or the rotation speed of the motor 1. Specifically, Fig.10 As shown, the torque threshold is set to be larger as the vehicle speed is lower. In addition, when the motor 1 outputs the driving torque as the driving force source of the vehicle Ve, the rotation speed increases or decreases according to the vehicle speed. Therefore, the torque threshold as described above can be set by either the vehicle speed or the rotation speed of the motor 1.

[0066] In addition, in the embodiment of the present invention, it is also possible to replace the above-mentioned torque threshold with a torque step difference threshold to determine whether the continuous switching operation can be performed. Fig.11 As shown, a torque step difference threshold is set as a threshold for determining whether a continuous switching operation can be performed. Moreover, for the current required driving torque, when the increase ratio (so-called torque step difference) of the predetermined required driving torque set in the gear position switched (the switching target) through the above-mentioned continuous switching operation is below the torque step difference threshold, the gear switching is permitted. When the increase ratio of the predetermined required driving torque set in the gear position of the switching target is greater than the torque step difference threshold, the gear switching is rejected (not permitted). In other words, if the increase ratio of the predetermined required driving torque set in the gear position of the switching target is within the switching permission judgment area set in consideration of the vehicle speed or the rotational speed of the motor 1, the actual switching of the gear position based on the continuous switching operation is permitted.

[0067] In this case, the torque step difference threshold is also preset in accordance with the vehicle speed or the rotation speed of the motor 1 based on the results of a real vehicle driving test, simulation, etc., for example. Fig.11 As shown, the torque step difference threshold is set to be larger as the vehicle speed is lower.

[0068] In addition, the torque threshold or torque step difference threshold as described above can also be changed according to the driving mode of the vehicle Ve. For example, in the case where the vehicle Ve is a structure that can selectively set a sports mode in addition to the standard driving mode (normal mode), it is also possible to compare the sports mode with the normal mode and make the torque threshold or torque step difference threshold larger. That is, the switching permission judgment area as described above can also be expanded. The sports mode is a driving mode that can be driven with a more dynamic acceleration characteristic compared to the normal mode. Therefore, in the sports mode, compared with the comfort and stability of the vehicle Ve, more emphasis is placed on the improvement of the operability, power performance and driving performance of the vehicle Ve, and as described above, the torque threshold or torque step difference threshold is set to a larger value. By increasing the torque threshold or torque step difference threshold to expand the switching permission judgment area, it is easy to allow the gear to switch. Therefore, even if the vehicle Ve is driving under a condition where a large driving torque is required, it is easy to implement the gear switching based on the continuous switching operation, thereby improving the operability of the vehicle Ve.

[0069] If the determination in step S4 is YES because the continuous DOWN switch signal is within the permissible range, that is, actual switching of the shift position by the continuous switching operation is permitted, the routine proceeds to step S5 .

[0070] In step S5, a further downshift, i.e., a so-called skip shift, is performed. In this case, the skip shift is a shift from the currently selected gear to a gear in a direction where the required driving torque increases by two or more steps. Fig. 9 In the example shown in the time chart, at time t6, continuous DOWN switch signals are allowed to be received. After this time t6, the gear is switched from the currently selected "D gear" to the "2 gear" where the required driving torque is increased by two levels, skipping "3 gear".

[0071] Next, in step S6, similar to the previous step S3, it is determined whether there is a continuous DOWN switch signal input. If the determination in step S6 is "yes" because there is a continuous DOWN switch signal input, that is, the driver has again performed a continuous shift operation on the gear position, the control returns to step S4 and the same control as before is performed.

[0072] On the other hand, if the determination in step S6 is "No" due to the lack of continuous DOWN switch signal input, the subsequent control is not executed and the current control is temporarily terminated. Figure 8 The procedure is shown in the flowchart.

[0073] On the other hand, if the determination in step S4 is "NO" because the continuous DOWN switch signal is outside the permissible range, that is, the actual switching of the shift position by the continuous switching operation is rejected, the routine proceeds to step S7.

[0074] In step S7, the acceptance of the continuous DOWN switch signal is determined to be unacceptable. That is, it is determined that the shifting of the gear position based on the continuous shifting operation is rejected. Fig. 9 In the example shown in the timing diagram, at time t6, the continuous DOWN switch signal is not accepted. After this time t6, the gear shift from the currently selected "D gear" to "2 gear" (shift jump) is not implemented, but the gear shift to "3 gear" where the required driving torque is only increased by one level is implemented. After that, the gear shift is temporarily terminated. Figure 8 The procedure is shown in the flowchart.

[0075] Thus, in the control device of the electric vehicle in the embodiment of the present invention, when the driver performs a continuous switching operation on the gear shift device 2, it is determined whether to allow the actual switching of the gear based on the continuous switching operation. For example, when the required driving torque set at the gear of the switching target is greater than the torque threshold, or when the increase ratio of the required driving torque set at the gear of the switching target relative to the current required driving torque is greater than the torque step difference threshold, it is determined that there is a possibility of a disordered behavior of the vehicle Ve, and the switching of the gear based on the continuous switching operation is rejected. When the required driving torque set at the gear of the switching target is less than the torque threshold, or when the increase ratio of the required driving torque set at the gear of the switching target relative to the current required driving torque is less than the torque step difference threshold, it is determined that there is no possibility of a disordered behavior of the vehicle Ve, and the switching of the gear based on the continuous switching operation is permitted. Therefore, the actual switching of the gear based on the continuous switching operation is appropriately implemented in a stable state without the concern of disordered behavior of the vehicle Ve. Moreover, by using the gear switching operation of the gear shift device 2 as described above, the speed change operation of a vehicle equipped with a transmission can be reproduced in a simulated manner.

[0076] Therefore, according to the control device for an electric vehicle in the embodiment of the present invention, it is possible to allow the driver to appropriately experience the same operational feeling as that of a conventional vehicle equipped with a transmission without degrading both the operability and the stability of the vehicle Ve.

Claims

1. A control device for an electric vehicle, the electric vehicle having at least a motor as a driving force source, the motor being controlled based on a control target value set corresponding to a required driving force, characterized in that: The control target value is set in a plurality of gears having different levels of torque characteristics relative to the rotation speed of the motor. The control device of the electric vehicle comprises: a gear shifting device for selecting any one of the plurality of gear positions according to a manual operation of a driver; and a controller that controls the output torque of the motor based on the control target value set according to the gear position selected by the shifting device, The controller is composed of: When a continuous switching operation is performed by the shift device to switch from the currently selected gear to another gear that is two or more different, it is determined whether the gear can be switched by the continuous switching operation based on the control target value set at the gear of the switching target.

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

3. The control device for an electric vehicle according to claim 1 or 2, characterized in that: The controller is composed of: When the continuous switching operation is performed, when the control target value set at the gear of the switching target is less than a torque threshold for determining whether the continuous switching operation is possible, the gear switching is permitted. When the control target value set at the shift target shift position is greater than the torque threshold, the shifting of the shift position is rejected.

4. The control device for an electric vehicle according to claim 3, characterized in that: The torque threshold value varies according to the vehicle speed or the rotation speed, The controller is composed of: When the control target value set at the gear of the switching target 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, the gear switching is permitted; When the control target value set at the shift target shift position is greater than the torque threshold value corresponding to the vehicle speed or the rotation speed when the continuous shift operation is performed, the shifting of the shift position is rejected.

5. The control device for an electric vehicle according to claim 4, characterized in that: The lower the vehicle speed or the rotation speed is, the greater the torque threshold is.

6. The control device for an electric vehicle according to claim 1 or 2, characterized in that: The controller is composed of: When the continuous switching operation is performed, when the increase ratio of the control target value set at the gear of the switching target relative to the current control target value is below the torque step difference threshold for determining whether the continuous switching operation can be performed, the gear switching is permitted. When the increase ratio is greater than the torque step difference threshold, the gear shift is rejected.

7. The control device for an electric vehicle according to claim 6, characterized in that: The torque step difference threshold value varies according to the vehicle speed or the rotation speed, The controller is composed of: When the increase ratio is equal to or less than the torque step difference threshold value corresponding to the vehicle speed or the rotation speed when the continuous switching operation is performed, the shifting of the gear is permitted; When the increase ratio is greater than the torque step difference threshold value corresponding to the vehicle speed or the rotation speed when the continuous switching operation is performed, the shifting of the gear position is rejected.

8. The control device for an electric vehicle according to claim 7, characterized in that: The lower the vehicle speed or the rotation speed is, the larger the torque step difference threshold is.

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