Manual speed shift simulation control device for electric vehicles

Abstract

A manual shift simulation control device for an electric vehicle simulates the behavior of the vehicle associated with manual shifting using an electric motor as a driving force source, thereby protecting or maintaining the durability of systems such as a power storage device. The device performs torque control to change the output torque of the electric motor based on a detection signal of a shift operation. When the output torque of the electric motor changes in response to the shift operation (step S3), the device changes the limit value of at least one of the output torque change rate and the power input / output amount in a direction that relaxes the limit (step S2). The shift operation includes intermittent torque simulation by a clutch mechanism; motor output increase / decrease operation by an accelerator mechanism associated with the intermittent simulated operation by the clutch mechanism; and mode selection operation by the shift mechanism.

Description

Technical Field

[0001] The present invention relates to a control device for expressing a behavior when a gear shift operation is performed in a vehicle equipped with a manual transmission in a vehicle using an electric motor as a driving force source. Background Art

[0002] The present applicant has proposed an electric vehicle with this function in Patent Document 1. This electric vehicle includes: a shifter, similar to a shifter used for shifting a manual transmission, that is operated to select one of multiple modes with step-by-step torque characteristics; and a clutch device that simulates the operation of a clutch mechanism that interrupts torque transmission between a driving force source and drive wheels. The device is configured to control the torque of the motor based on a signal including the mode selected by the shifter and a signal including the clutch device's operating amount. Specifically, in the device described in Patent Document 1, the torque transmitted from the motor to the drive wheels is reduced as the clutch device's operating amount, which corresponds to the amount of clutch pedal depression, increases. Furthermore, the torque transmitted from the motor to the drive wheels is increased or restored as the clutch device's operating amount, which corresponds to the clutch pedal being depressed and released, decreases, and the selected mode is combined with the clutch device's operating amount.

[0003] Furthermore, when switching the clutch from a released state to an engaged state and increasing the torque transmitted through the clutch, an excessively large change in torque can produce a so-called shock, causing a sense of discomfort. Conversely, a slow change in torque can degrade the responsiveness of shifting or acceleration. Therefore, in the device described in Patent Document 2, while increasing the transmitted torque at the point in time when the friction element transitions from a slipping state to a fully engaged state, the torque change rate of the motor, serving as the driving force source, is controlled based on the difference in torque before and after the change and the driver's drive request.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 6787507

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2011-20542 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] The motor mounted on an electric vehicle as a driving force source performs power operation and outputs driving torque. In addition, it outputs braking torque through energy regeneration. Therefore, by utilizing this diversity of output torque, it is possible to exhibit the same behavior as a vehicle equipped with a manual transmission, as described in Patent Document 1. The energy source of this motor is a storage device mainly composed of a secondary battery. In order to operate the motor in a manner that simulates the behavior during manual transmission operation, discharge from the storage device and charging to the storage device are repeated. When charging and discharging in the storage device, heat is inevitably generated. In addition, there are problems such as electrolyte deterioration. Therefore, excessive charging and discharging becomes a factor in the deterioration of the storage device, reducing the durability of the storage device. Therefore, usually, restrictions are set on the discharge and charging of the storage device.

[0010] Manual shifting is typically performed by the driver to change the vehicle's behavior (primarily the driving torque) as desired. Therefore, not only must the shifting operation itself be rapid, but the resulting driving torque or braking torque must also change rapidly or responsively. To simulate the vehicle's behavior during such manual shifting, the motor outputs driving torque and braking torque, causing the motor torque to change rapidly and significantly, requiring a large charge and discharge capacity from the power storage device. However, as mentioned above, power storage devices are subject to limitations for reasons such as maintaining durability. These limitations may prevent the power storage device from discharging the required power to simulate the vehicle's behavior during manual shifting, or may prevent charging. In such cases, the driver's desired vehicle behavior may not be achieved, leading to a feeling of discomfort. Thus, with conventional technology, there is a need to develop new technologies that balance the durability of the power storage device achieved by limiting the charge and discharge capacity with the control required to simulate the vehicle's behavior during manual shifting.

[0011] The present invention is made with a view to the above-mentioned technical problems, and its purpose is to provide a control device that can take into account both "torque control without excess or deficiency" and "maintaining the durability of control systems such as storage devices or suppressing degradation" when controlling the torque of a motor serving as a driving force source of an electric vehicle to simulate the behavior of the vehicle during manual shifting operation.

[0012] Technical solutions to problems

[0013] In order to achieve the above-mentioned object, the present invention provides a manual transmission simulation control device for an electric vehicle, comprising: an electric motor as a driving force source; an accelerator mechanism, operated by a driver to increase or decrease the output of the electric motor; a power storage device, connected to the electric motor, and capable of limiting at least one of a rate of change of output torque and an amount of power input and output; a clutch mechanism, operated by the driver to simulate an intermittent clutch operation for transmitting torque between the electric motor and the drive wheels; and a shift mechanism, operated by the driver to select a mode as a relationship between the output of the electric motor and the drive torque at the drive wheels. The manual transmission simulation control device for an electric vehicle is characterized in that A controller for controlling the torque of the electric motor is provided, the controller being configured to perform torque control to change the output torque of the electric motor based on a detection signal of a gear shifting operation, the gear shifting operation comprising: an intermittent simulation operation of the torque performed by the clutch mechanism; an output increase or decrease operation of the electric motor performed by the accelerator mechanism in association with the intermittent simulation operation; and a mode selection operation performed by the gear shifting mechanism, the controller being configured to change the limit value of at least either the output torque change rate or the power input / output amount in a direction that alleviates the limit when the output torque of the electric motor changes accompanying the gear shifting operation.

[0014] In the present invention, the controller may relax the restriction (relax the restriction) when the clutch mechanism performs a simulated operation of cutting off the torque or performs a simulated operation of transmitting the torque.

[0015] In addition, in the present invention, the controller may relax the restriction during a predetermined time after a cut-off simulation operation of cutting off the torque is performed by the clutch mechanism, or during a predetermined time after a connection simulation operation of transmitting the torque is performed by the clutch mechanism.

[0016] Moreover, in the present invention, the controller may include a hypothetical vehicle having a transmission whose speed ratio is switched by the shift mechanism and an engine connected to the transmission as a control model, and calculates a hypothetical engine speed based on the speed ratio assumed to be set by the transmission and a predetermined rotational speed equivalent to the vehicle speed of the electric vehicle, and relaxes the restriction when the hypothetical engine speed is above a predetermined base speed.

[0017] In the present invention, the controller may determine whether a protection requirement for the electric motor or the power storage device is met, and regulate relaxation of the restriction when the protection requirement is met.

[0018] In the present invention, the controller may regulate the relaxation of the restriction so that the change of the restriction value in the direction of relaxing the restriction when performing a cut-off simulation operation of cutting off the torque through the clutch mechanism takes precedence over the change of the restriction value in the direction of relaxing the restriction when performing a connection simulation operation of transmitting the torque through the clutch mechanism.

[0019] Effects of the Invention

[0020] According to the present invention, in an electric vehicle that uses an electric motor as a driving force source and is capable of performing a shifting operation that simulates a manual shifting operation, when this shifting operation is performed, the output torque of the electric motor is varied to produce behavior similar to that of a vehicle equipped with a manual transmission. In this case, if the electric motor needs to be discharged or charged beyond the input / output limits set for the power storage device connected to the electric motor, the limit is varied in a direction that relaxes the limit. This allows the electric motor torque to be varied sufficiently to reproduce the behavior associated with the shifting operation. In other words, it is possible to produce behavior that is similar to or similar to that of the vehicle during a manual shifting operation in a vehicle equipped with a manual transmission. Furthermore, since the shifting operation, which involves operating the clutch mechanism, shift mechanism, etc., is performed in a short time, the relaxation of the limit is performed based on the shifting operation. Therefore, the relaxation time is short, which does not significantly increase the load on the power storage device and does not significantly degrade its durability. In other words, according to the present invention, it is possible to achieve the necessary and sufficient behavior that simulates the behavior of the vehicle during a manual shifting operation without compromising the durability of the power storage device.

[0021] In addition, in the present invention, when the protection requirements for the electric motor and the storage device are met, even if the limit values ​​of the output torque change rate or the power input and output amount from the storage device change in the direction of easing these restrictions, the amount of change is also regulated. For example, compared with "easing the restrictions when the clutch mechanism is cut off in a manner of cutting off the torque", "easing the restrictions when the clutch mechanism that has cut off the torque is connected in a manner of transmitting the torque" is more strongly regulated. In other words, the relaxation of the above-mentioned restrictions when the torque is cut off is given priority over the relaxation of the above-mentioned restrictions when the torque is transmitted. Therefore, it is possible to more reliably avoid or suppress situations such as the movement of the vehicle body in the opposite direction of the torque cut-off when the torque is cut off in conjunction with the gear shifting operation, and thus it is possible to prevent or suppress situations that give the driver a sense of discomfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a diagram schematically showing the configuration of an electric vehicle according to an embodiment of the present invention.

[0023] Figure 2This diagram shows the configuration of an ECU that performs motor torque control using functional blocks.

[0024] Figure 3 This is a flowchart for explaining the restriction relaxation control performed in the embodiment of the present invention.

[0025] Figure 4 The torque waveform diagram schematically shows changes in motor torque for simulating the behavior during manual shifting in a hypothetical vehicle or MT vehicle, with respect to cases where the restriction is relaxed and cases where the restriction is not relaxed.

[0026] Description of Reference Numerals

[0027] 1 motor;

[0028] 2 front wheels;

[0029] 3. Electricity storage device;

[0030] 6. Drive shaft;

[0031] 10 converters;

[0032] 11 ECU;

[0033] 12 accelerator pedal;

[0034] 13 accelerator position sensor;

[0035] 14 brake pedal;

[0036] 15 brake sensor;

[0037] 16 rotation speed sensor;

[0038] 17 gear shift mechanism;

[0039] 18 clutch pedal;

[0040] 19 Speed ​​shift position (gear) sensor;

[0041] 20 clutch position sensor;

[0042] 110: a hypothetical engine rotation speed calculation unit;

[0043] 111: a hypothetical engine output torque calculation unit;

[0044] 112 torque transfer gain calculation unit;

[0045] 113 clutch output torque calculation unit;

[0046] 114 gear ratio calculation unit;

[0047] 115 transmission output torque calculation unit;

[0048] 116 Restriction Department;

[0049] 117 Restriction Mitigation Department;

[0050] Ve Electric Vehicle. DETAILED DESCRIPTION

[0051] The present invention will be described based on the embodiments shown in the drawings. The embodiments described below are merely examples of the present invention and do not limit the present invention.

[0052] Figure 1 An example of an electric vehicle (hereinafter referred to as a vehicle) in an embodiment of the present invention is schematically shown. The vehicle Ve is a front-wheel drive vehicle that has a motor (MG) 1 as a driving force source and transmits torque from the motor 1 to a pair of front wheels 2 to travel. The motor 1, like the motors previously known to be provided in electric vehicles and hybrid vehicles, can be composed of a so-called electric generator. In addition to the function of a motor that outputs a driving torque by supplying electricity from a battery device (BATT) 3, the electric generator also has the function of a generator that generates electricity by forcibly rotating by torque transmitted from the outside. Specifically, a permanent magnet synchronous motor or an induction motor can be used. In addition, the torque during power generation is a so-called negative torque that acts in the direction of reducing the torque from the outside, so it acts as a braking force in the vehicle Ve. The motor 1 is equivalent to the "electric motor" in the embodiment of the present invention.

[0053] The output shaft 4 of the motor 1 is connected to a gear mechanism 5, which is further connected to a differential gear mechanism 7 as a final reducer via a propeller shaft 6. The output torque of the motor 1 is distributed to the left and right drive shafts 8 via the differential gear mechanism 7, and the pair of front wheels (drive wheels) 2 connected to these drive shafts 8 are driven by the motor 1 to cause the vehicle Ve to travel. Figure 1 The vehicle Ve shown is a front-wheel drive vehicle, but the electric vehicle in the present invention can also be a rear-wheel drive electric vehicle that transmits torque from a motor 1 to a pair of rear wheels 9 to travel. In addition, it can also be a four-wheel drive vehicle that is provided with a transfer case and transmits torque from a motor 1 to a pair of front wheels 2 and a pair of rear wheels 9 to travel.

[0054] An inverter (INV) 10 is provided for controlling the magnitude of the current supplied to the motor 1 and the frequency of the current supplied to each phase. A power storage device (BATT) 3 that outputs a DC current is connected to the inverter 10. Furthermore, in addition to the inverter 10, other electrical equipment such as a converter for amplifying the voltage output from the power storage device 3 may be provided. Furthermore, the power storage device 3 may include power storage components such as capacitors in addition to secondary batteries such as lithium-ion batteries.

[0055] An electronic control unit (hereinafter referred to as ECU) 11 is provided for controlling the switching elements of the inverter 10. This ECU 11 corresponds to the "controller" in the present embodiment and, like conventional ECUs installed in vehicles, is primarily composed of a microcomputer. It is configured to receive signals from various sensors, perform calculations based on these input signals and pre-stored calculation formulas or maps, and output the results of these calculations as control signals to various devices such as the inverter 10.

[0056] Figure 1 The illustrated vehicle Ve is equipped with an accelerator pedal 12, which is operated by a driver (not shown) for acceleration and deceleration (acceleration and deceleration) (output increase and decrease operation), and an accelerator position sensor 13 that detects the amount of accelerator pedal depression. Furthermore, a brake pedal 14, which is operated by the driver for deceleration or parking, and a brake sensor 15 that detects the amount of accelerator pedal depression and the force of accelerator pedal depression are provided. Furthermore, a vehicle speed sensor (rotational speed sensor) 16 is provided for detecting the rotational speed of the propeller shaft 6 (i.e., vehicle speed). These sensors 13, 15, and 16 are connected to the ECU 11, and their respective detection signals (detected data) are input to the ECU 11.

[0057] Figure 1 The vehicle Ve shown is also equipped with a device for simulating manual gear shifting operations. First, a gear shift mechanism 17 is provided, which is mainly composed of a gear shift lever or a paddle switch (paddle switch) and the like, and is used to manually select a plurality of forward gears, reverse gears, and neutral gears that do not actually exist. When performing a gear shifting operation in a vehicle equipped with a manual transmission, in order to be able to connect and disconnect the gears, and in order to reduce the gear shifting shock, the torque transmission between the driving force source such as the engine and the drive wheels is temporarily cut off. The clutch used for this is usually cut off or connected (intermittently) by a clutch pedal. In Figure 1The illustrated vehicle Ve is equipped with a clutch pedal 18 serving as a clutch mechanism, simulating a vehicle equipped with such a manual transmission. Furthermore, a shift position sensor 19 is provided to detect the position (or mode) of the shift gear selected by the shift mechanism 17, and a clutch position sensor 20 is provided to detect the amount of depression of the clutch pedal 18. These sensors 19 and 20 are connected to the aforementioned ECU 11, and their respective detection signals (detected data) are input to the ECU 11.

[0058] The vehicle Ve described above is configured to not only perform conventional EV driving, in which the torque of the motor 1 is controlled to drive and brake according to the driver's driving request expressed as the accelerator position, but also to display driving and shifting behavior that simulates the driving and shifting operations of a vehicle equipped with a manual transmission (hereinafter referred to as an MT vehicle). The control for simulating the driving of this MT vehicle can be the control described in Patent Document 1, which is briefly described below.

[0059] A model of a MT vehicle to be simulated is pre-set and stored as a numerical model in the ECU 11. The actual accelerator opening (depression amount) detected by the accelerator position sensor 13, the shift position of the shift mechanism 17 detected by the shift position sensor 19, the actual depression amount of the clutch pedal 18 detected by the clutch position sensor 20, and the actual rotational speed of the propeller shaft 6 detected by the rotational speed sensor 16 are applied to the modeled MT vehicle. The torque (driving torque and braking torque) to be output by the motor 1 is calculated, and the inverter 10 is controlled by the ECU 11 to achieve the torque. The modeled MT vehicle (hereinafter referred to as the virtual vehicle) includes an internal combustion engine (engine) and a stepped transmission connected to its output side. The virtual engine rotational speed, representing the engine's rotational speed, is calculated based on the actual operating conditions input from the aforementioned sensors 13, 19, 20, and 16. For example, the virtual engine rotation speed can be calculated by multiplying the rotation speed of the transmission shaft 6 detected by the rotation speed sensor 16 by the gear ratio at the gear shift position (gear stage) selected by the gear shift mechanism 17, and further multiplying it by the slip ratio corresponding to the amount of depression of the clutch pedal 18 detected by the clutch position sensor 20. The functional unit or functional block that performs such calculations is shown as the "virtual engine rotation speed calculation unit 110" in FIG. Figure 2 .

[0060] Since the hypothetical engine mounted on the hypothetical vehicle is an engine whose displacement, the relationship between the rotational speed and the output torque, and the efficiency are predetermined in the design, the output torque of the hypothetical engine can be calculated based on the value, the accelerator position, and the map for the hypothetical engine that predetermines the relationship between the rotational speed and the output torque. The functional unit or functional block that performs such calculations is shown as "hypothetical engine output torque calculation unit 111" in FIG. Figure 2 .

[0061] It is assumed that the clutch mechanism in the hypothetical vehicle is a friction clutch whose transmission torque capacity continuously changes. Therefore, a predetermined relationship determined by design is established between the amount of depression of the clutch pedal and the transmission torque capacity, and this relationship can be prepared in advance as a mapping and stored in advance in the ECU11. For example, it can be set as the following mapping: the transmission torque capacity is set to a gain that changes between "0" and "1", and the gain is "1" during the period when the amount of depression of the clutch pedal is between "0" and a predetermined value. As the depression amount further increases, the gain gradually (linearly or proportionally) decreases according to the depression amount. Therefore, the torque output from the hypothetical clutch mechanism assumed to be mounted on the hypothetical vehicle is determined according to the above-mentioned gain, and the gain can be calculated based on the above-mentioned mapping and the actual amount of depression of the clutch pedal 18 detected by the clutch position sensor 20. The functional unit or functional block that performs such calculations is shown as a "torque transfer gain calculation unit 112" Figure 2 .

[0062] The torque input to the manual transmission assumed to be mounted on the hypothetical vehicle is the torque resulting from the change in the hypothetical engine output torque according to the aforementioned gain, i.e., the clutch output torque. Therefore, the clutch output torque can be calculated by multiplying the hypothetical engine output torque calculated by the hypothetical engine output torque calculation unit 111 by the gain calculated by the torque transfer gain calculation unit 112. The functional unit or functional block that performs such calculations is shown as the "clutch output torque calculation unit 113" in FIG. Figure 2 .

[0063] In order to simulate the gear ratio (speed ratio) set in the manual transmission in the hypothetical vehicle, the gear ratio in the manual transmission is calculated based on the actual driving state of the above-mentioned vehicle Ve. The gear ratio is the ratio of the engine speed in the hypothetical vehicle to the output speed of the manual transmission (specifically, the rotation speed of the drive shaft). The aforementioned hypothetical engine rotation speed is equivalent to the engine speed in the hypothetical vehicle. In addition, the rotation speed of the drive shaft 6 detected by the aforementioned rotation speed sensor 16 is equivalent to the output speed. Therefore, the gear ratio can be obtained by dividing the hypothetical engine rotation speed by the rotation speed of the drive shaft 6. The functional unit or functional block that performs such calculations is shown as a "gear ratio calculation unit 114" Figure 2 .

[0064] In order to make the behavior of the vehicle Ve described above consistent or similar to that of the virtual vehicle, including the behavior during the gear shift, the output torque of the motor 1 is controlled so that the torque of the propeller shaft 6 is consistent or similar to the output torque of the manual transmission in the virtual vehicle. Therefore, it is necessary to calculate the output torque of the manual transmission in the virtual vehicle. This is done by Figure 2 The transmission output torque calculation unit 115 is a functional unit or functional block described in the manual transmission. Specifically, the manual transmission increases or decreases the input torque according to the gear ratio and outputs it. Therefore, the transmission output torque is calculated by multiplying the aforementioned clutch output torque input to the manual transmission by the gear ratio. The clutch output torque is a torque that reflects the gain calculated by the above-mentioned torque transfer gain calculation unit 112, and therefore becomes a torque corresponding to the intermittent transmission torque capacity of the clutch mechanism during the speed transition. Therefore, by controlling the converter 10 by the ECU 11 to realize the torque calculated by the transmission output torque calculation unit 115 (the torque at the drive shaft 6), the behavior of the virtual vehicle during the speed change can be simulated and displayed on the above-mentioned actual vehicle Ve.

[0065] On the other hand, the transmission output torque during gear shifting in the hypothetical vehicle varies significantly due to torque fluctuations caused by torque cutoff by the clutch mechanism, the start of torque transmission (so-called engagement of the clutch mechanism), and torque fluctuations caused by torsion of the manual transmission and the vehicle body associated with these torque changes. Simulating these torque changes by varying the torque of motor 1 places a heavy load on power storage device 3 and inverter 10. Furthermore, excessive discharge and charging of power storage device 3 could reduce its durability or cause damage.

[0066] Therefore, a restriction unit 116 is provided to restrict discharge from the power storage device 3 to the motor 1 and charge from the motor 1 to the power storage device 3. Figure 2As shown, the limiting unit 116 is a functional unit or block in the ECU 11. It sets an upper limit (limit value) for at least one of the output torque change rate and the power input / output amount, thereby controlling the converter 10 so that the charge / discharge amount in the power storage device 3 or the rate of change thereof does not exceed the upper limit value. The upper limit value is primarily for protecting the power storage device 3 and can therefore be pre-set in the design based on the characteristics, degradation state, SOC, temperature, and other factors of the power storage device 3.

[0067] The degree of restriction for protecting the power storage device 3 includes severe restriction to prevent degradation exceeding that which would occur over time under normal usage, moderate restriction to prevent permanent damage even if temporary degradation occurs, and mild restriction to avoid or prevent damage that would not immediately lead to functional failure. When restrictions are graded in this manner, the upper limit is set to a low value for severe restriction, the maximum value for mild restriction, and a value in between for moderate restriction.

[0068] In the embodiment of the present invention, the above-mentioned restrictions are modified, and the above-mentioned severe restrictions are normally applied, and when predetermined conditions are met, the severe restrictions are relaxed to moderate or mild restrictions. Figure 2 In the embodiment described herein, when the motor 1 is controlled in a manner simulating the vehicle behavior (transmission output torque) associated with manual gear shifting in the aforementioned hypothetical vehicle, the restriction imposed by the restriction unit 116 on the output torque change rate and the power input / output is relaxed by the restriction relaxation unit 117.

[0069] Hereinafter, the control for relaxing the restriction described above will be described together with the torque control for simulating the behavior of the vehicle when a manual shift operation is performed. Figure 3 This is a flowchart for explaining an example of the control for relaxing the restriction, which is executed by the ECU 11 in the vehicle Ve described above while the clutch pedal 18 and the shift mechanism 17 are enabled and the vehicle is traveling. Therefore, the ECU 11 corresponds to the controller in the embodiment of the present invention. Figure 3 In the control example shown, a determination is made as to whether the hypothetical engine speed Ne is greater than or equal to a predetermined reference speed α (step S1). This reference speed α is a speed used to determine whether the load on the power storage device 3 and the inverter 10 (hereinafter collectively referred to as the load on the power storage device 3) is high when the torque of the motor 1 is varied to simulate the behavior of a hypothetical vehicle in response to a simulated disconnection operation such as depression of the clutch pedal 18 constituting the clutch mechanism.

[0070] Specifically, if the virtual engine speed Ne is high, the virtual engine speed Ne will drop significantly as the clutch mechanism is simulated for disconnection. Therefore, if the associated behavior of the vehicle Ve is manifested through torque control of the motor 1, the amount of electric power input and output to and from the power storage device 3, or the rate of change of torque, will increase, increasing the load on the power storage device 3. This load varies depending on the driving state, such as vehicle speed, so the reference speed α should be set to a value that corresponds to the driving state of the vehicle Ve at that point in time.

[0071] In the case where the judgment in step S1 is "yes", the process goes to step S2, changes (increases) the upper limit of the output torque change rate (torque rate), and then returns. That is, in the case where the judgment in step S1 is "yes", it is considered that the load during the expected subsequent speed change is greater than the load in the normal state and exceeds the normal limit (heavy limit) set by the aforementioned limiting unit 116. Therefore, in order to be able to use the output torque of the motor 1 to make the behavior of the vehicle accompanying the manual speed change operation appear, in other words, in order to be able to input and output the power storage device 3 for realizing such a behavior, the upper limit of the torque rate is increased to relax the restriction. In addition, in the case where the judgment in step S1 is "no", there is no need to relax the restriction, so no special control is performed but the previous state is maintained.

[0072] On the other hand, in parallel with the determination of step S1, it is determined whether the clutch is being operated (step S3). "In clutch operation" here means that the amount of depression of the clutch pedal 18 is changing (increasing or decreasing), and is a state in which a cut-off simulation operation for cutting off the torque is being performed or a connection simulation operation for transmitting the torque is being performed. In the case where the clutch is cut off for speed change in the MT vehicle, the driving torque transmitted to the drive wheel suddenly becomes zero. If the behavior of the MT vehicle in this case is simulated in the above-mentioned vehicle Ve, it is necessary to use the torque of the motor 1 to create a behavior in which the driving torque is suddenly lost, which will cause the torque of the motor 1 to change significantly. In order to produce such a torque change, the input and output amount or the torque change rate in the storage device 3 becomes larger, and the load on the storage device 3 increases. In order to be able to perform such input and output, when it is determined to be "yes" in step S3, the above-mentioned step S2 is entered to relax the restriction.

[0073] In addition, when the clutch is connected (engaged) in the virtual vehicle, the front and rear vibration (shaking) of the vehicle body is generated due to the increase in driving torque. If such behavior is simulated using the torque of motor 1, the torque of motor 1 will become larger and change repeatedly. This is considered to be a factor in the increase in the load of the storage device 3. Therefore, the restriction is also relaxed in the continuous simulation operation of the transmission torque (step S2). In addition, if the judgment is "no" in step S3, there is no need to relax the restriction, so no special control is performed but the previous state is maintained.

[0074] Moreover, in parallel with the above-mentioned steps S1 and S3, it is determined whether the time elapsed after the continuous simulated operation of the clutch pedal 18 is within t seconds (step S4). When the clutch is connected after a manual shift operation is performed in an MT vehicle, a torsion is generated in the torque transmission system from the transmission to the drive wheels, which is the cause of the front and rear vibration of the vehicle body. Such vibration occurs within a predetermined time period after the clutch is connected. If the behavior in such an MT vehicle is simulated by the motor 1 in the above-mentioned vehicle Ve, it is necessary to increase the torque of the motor 1 and change it repeatedly, so the load on the power storage device 3 increases. That is, the increase in the load of the power storage device 3 after the clutch is connected occurs within a predetermined time period, so the above-mentioned t seconds can be determined in the design according to the assumed virtual vehicle.

[0075] In the case where the judgment in step S4 is "No", there is no need to relax the restriction, so no special control is performed but the previous state is maintained. In contrast, in the case where the judgment in step S4 is "Yes", it is determined whether there is a regulation based on the protection request (protection requirement) of the entire system including the control system such as the aforementioned motor 1, the power storage device 3, and the converter 10 (step S5). That is, the system generates heat due to operation, and there are temperature conditions for normal operation. If the temperature is higher than its limit temperature, the operation (control) is regulated. In addition, if a situation such as an abnormality is detected in some part, the operation (control) is regulated. In step S5, it is determined whether there is such a regulation. If the judgment result is "No", that is, if there is no regulation, the above-mentioned step S2 is entered to relax the restriction.

[0076] In contrast, when it is determined to be "yes" in step S5, no special control is performed but the previous state is maintained. That is, the restriction is not relaxed, and the output torque change rate and the power input and output are restricted at the level of the normal state. Therefore, in this case, the torque of the motor 1 cannot be changed in a manner that creates the behavior to be simulated. However, although such torque restriction has the effect of reducing or preventing the front and rear vibrations of the vehicle body after the speed change, it does not restrict the travel of the vehicle Ve. On the contrary, it is beneficial to the protection of the system including the power storage device 3 and the motor 1 or the maintenance of durability. Therefore, in Figure 3In the control example shown, the relaxation of the restriction described above is performed with priority given to the disconnection of the simulated operation over the continuation of the simulated operation of the clutch mechanism, thereby avoiding or suppressing the vehicle behavior contrary to the driver's intention as much as possible.

[0077] For example, Figure 3 The control shown is for a case where the vehicle is shifted from the first forward speed to the second forward speed during travel, and the change in motor torque will be described. Figure 4 It is a timing diagram schematically showing an example of changes in motor torque and parameters used therefor. Here, the gear stage (speed ratio) is the gear stage (speed ratio) in the imaginary vehicle that the CPU 11 has as a control model, and as an example, is pre-set to the following two-dimensional map (speed map), which has the vehicle speed or the rotational speed of a predetermined rotating component equivalent to the vehicle speed (for example, the rotational speed of the drive shaft) and the drive requirement amount that can be represented by the amount of depression of the accelerator pedal as parameters. Therefore, the imaginary speed ratio (hereinafter sometimes referred to as the speed ratio) in the above-mentioned vehicle Ve can be obtained by the accelerator position detected by the accelerator position sensor 13 (hereinafter sometimes referred to as the accelerator opening), the rotational speed of the drive shaft 6 detected by the rotational speed sensor 16 (hereinafter sometimes referred to as the output speed), and the above-mentioned speed map. Figure 4 The example shown schematically shows a change in torque when the vehicle is traveling in the first gear set as described above and then shifting to the second gear by manual operation.

[0078] When the accelerator pedal 12 is depressed and the accelerator opening is maintained at a predetermined opening, the motor 1 outputs drive torque in response, and the vehicle speed gradually increases, and the virtual engine speed Ne also gradually increases. In this so-called normal driving state, the upper limit of the torque ratio, as an example of output limitation, is set to a predetermined value β1, which corresponds to a heavy limit.

[0079] When the engine speed Ne is assumed to gradually increase and reach the aforementioned reference speed α (time point t1), Figure 3 In the flowchart shown in FIG. 1 , if the judgment is “Yes”, the upper limit value of the torque rate is changed. Figure 4 In FIG. 5 , the upper limit value after the change is represented by a value β2 (>β1) which is larger than the predetermined value β1.

[0080] When the hypothetical engine speed Ne increases to a certain extent as the vehicle speed increases, as an operation associated with shifting up to the second gear, the driver first returns the accelerator pedal 12 to its original position, removes the foot from the accelerator pedal 12, and prepares for stepping on the clutch pedal 18 (time point t2). That is, the accelerator opening decreases toward zero. When the accelerator pedal is returned to its original position and the accelerator opening is reduced in the hypothetical vehicle or MT vehicle, the engine torque and the drive torque decrease accordingly, so the vehicle decelerates. In order to simulate the behavior of such a hypothetical vehicle or MT vehicle, the torque of the motor 1 is sharply reduced, and a regenerative braking force is also generated. In this case, electric power is input and output from the power storage device 3 to increase the torque rate. Figure 4 In the example shown, the limitation of the torque rate is relaxed and its upper limit is increased to a predetermined value β2, so that the torque of the transmission shaft 6 can be made Figure 2 The motor torque is controlled in the manner of the torque calculated by the transmission output torque calculation unit 115. In this case, the clutch pedal 18 is not depressed yet and is in the engaged state (ON state). Therefore, the virtual engine speed Ne increases in the same manner as the previous change in vehicle speed.

[0081] When the accelerator pedal 12 is depressed back to its original position and the clutch pedal 18 is depressed (time point t3), the accelerator opening becomes zero, and the engine braking action is performed in the virtual vehicle. In addition, the transmission torque capacity based on the clutch mechanism gradually decreases according to the amount of depression of the clutch pedal. In this process, the vehicle is braked by the engine braking force, and its braking force (deceleration) gradually decreases. In order to simulate such behavior by the motor 1, the motor 1 is controlled to function as a generator and is controlled in a manner such that its regenerative braking force (so-called negative torque) gradually decreases. Therefore, the motor 1 decreases its regenerative braking force at a predetermined gradient from a state in which a large regenerative braking force is generated, so that the charge amount or torque change rate of the power storage device 3 becomes larger. However, since the upper limit value is increased in order to ease the limitation of the torque rate, the motor 1 can generate regenerative braking force without restriction and generate the deceleration required by the vehicle Ve. That is, the behavior of the virtual vehicle can be simulated.

[0082] When the clutch pedal is fully depressed and the clutch is released (OFF) in the hypothetical vehicle, the engine is disconnected from the drive wheels, eliminating the engine's braking action. To simulate this behavior in the aforementioned vehicle Ve, the motor torque is controlled to zero at the point in time (time t4) when the clutch pedal 18 is fully depressed and OFF. In other words, regenerative braking is eliminated. Furthermore, since torque control of motor 1 is temporarily terminated, the torque rate limit is relaxed, and the upper limit of the torque rate returns to the original predetermined value β1.

[0083] In this way, the front wheel (drive wheel) 2 is controlled to have no driving torque or braking torque applied thereto. In this control state, the shift mechanism 17 is operated to switch from the 1st gear (1st) position to the 2nd gear (2nd) position via the neutral position (N) (time point t5 to time point t6).

[0084] The clutch pedal 18 is then returned to its original position and the accelerator pedal 12 is depressed (time t7). Furthermore, the output torque of the motor 1 gradually increases in accordance with the increase in the accelerator opening. In this case, if the clutch pedal 18's return speed (release speed) and the accelerator pedal 12's depression speed are fast for rapid gear changes, the motor 1 needs to rapidly increase its output torque. To achieve this, the torque rate limit is relaxed, with the upper limit raised from the normal predetermined value β1 to β2.

[0085] Until the clutch pedal 18 is fully depressed and returned to the engaged state (ON state) (until time t8 ), the torque rate limitation is continuously relaxed because the torque transmission by the clutch mechanism is in continuous operation.

[0086] As mentioned above, when the clutch is connected to complete the gear change in the virtual vehicle or the normal MT vehicle, a torque corresponding to the gear ratio and accelerator opening after the gear change is applied to the drive wheels. Therefore, the change in torque may cause front and rear vibration (or shaking). In order to simulate such behavior, Figure 4 In the example shown, the motor torque is increased overall while varying in magnitude. The magnitude and period of variation in this case can be determined by simulation using a virtual vehicle or MT vehicle or by actual measurement. As such front-to-back vibrations gradually converge, the variation in torque required of the motor 1 gradually decreases. In other words, the load applied to the power storage device 3 gradually decreases with such torque variation. Therefore, after a time period (assuming that the load does not exceed the upper limit) has passed, Figure 3 At a time point (time point t9) after t seconds (shown in step S4), the relaxation of the torque rate limitation is completed, and the upper limit value is returned to the predetermined value β1.

[0087] In addition, in order to reduce the reduction of the driving torque during the speed change or to shorten the reduction of the driving torque during the speed change, the clutch pedal 18 may be depressed while the accelerator pedal 12 is depressed to a certain extent to start the speed change operation. Figure 4 This example is shown by a dotted line. At time t3 when the clutch pedal 18 starts to be depressed, the accelerator pedal 12 is depressed as before. While the clutch pedal 18 is being depressed (time t10), the accelerator pedal 12 is depressed back (released).

[0088] In this case, the time from when the accelerator opening begins to decrease (from time t10) to when the clutch is completely released (OFF) (until time t4) is short, and the motor torque is reduced to zero during this period. Therefore, the high torque rate increases the load on the power storage device 3. However, by using the start of the shift operation as the trigger (factor) for starting the clutch pedal 18, the torque rate (the rate of change of the output torque) is relaxed, allowing the motor torque to change rapidly and significantly, creating the behavior of the electric vehicle Ve that simulates the behavior of a vehicle during manual shifting.

[0089] Furthermore, although the load on the power storage device 3 may increase due to the high torque rate, the time the clutch pedal 18 is depressed is short, and the high load is applied for a short period of time. Therefore, the temperature increase of the power storage device 3 and the inverter 10 accompanying the load change is quickly eliminated, and damage to the power storage device 3 and other components, or a decrease in durability, does not become a particular problem. In other words, by appropriately setting the degree of relaxation of the restriction, damage to the power storage device 3 and other components, or a decrease in durability, can be avoided.

[0090] Here, for reference, the change in motor torque when the above-mentioned restriction is not relaxed is described. For example, when the torque rate is maintained at the heavily restricted state as in normal conditions, and the torque of the motor 1 is controlled in a manner simulating the behavior of a MT vehicle with manual transmission, the torque of the motor 1 cannot be changed sharply due to the restriction of the torque rate (output torque change rate) in the power storage device 3. Therefore, at the time when the hypothetical engine speed Ne reaches the reference speed α or the accelerator pedal 12 begins to be depressed and returned to its original position, the motor torque cannot be immediately reduced, for example, as shown in FIG. Figure 4 The previous motor torque is maintained as shown by the mid-dash line. As a result, even though the driver intentionally shifts gears to reduce the drive torque to zero, the vehicle continues to be driven by the output from the power source, creating a driving state contrary to the driver's intention and causing a sense of discomfort to the driver. This undesirable situation can be eliminated or suppressed by relaxing the restrictions on the output torque change rate and power input and output, as in the embodiments of the present invention.

[0091] The driving state of the vehicle Ve varies depending on the traffic conditions and road surface conditions, and there may be situations where a gear change is required during driving that requires a large driving force. In such a situation, since a large load is applied to the system including the power storage device 3, the inverter 10, and the motor 1, sometimes the higher load is suppressed and the protection of the system is prioritized. In this situation, when manual gear shifting is performed, the protection of the system is prioritized. The control for this is the aforementioned Figure 3In the control of step S5 shown, if there is a regulation for easing the limit based on system protection, the previous control state is maintained and the limit is not relaxed. As a result, the motor torque is controlled to the upper limit of the output torque change rate and the power input and output. Therefore, for example, Figure 4 It changes linearly as shown by the two-dot chain line in the figure. Therefore, the system can be protected. In contrast, it is impossible to simulate the front-to-back vibration (or shaking) after the speed change in the virtual vehicle or MT vehicle. However, such front-to-back vibration (or shaking) is inevitable and is not intentionally generated by the driver, so even if such front-to-back vibration (or shaking) cannot be simulated in the above-mentioned vehicle Ve, it will not cause any particular sense of incongruity. In other words, it is possible to take into account both the simulation of the vehicle's behavior during manual shifting and the protection or durability maintenance of the system including the power storage device 3.

[0092] In addition, the present invention is not limited to the above-mentioned embodiment. Although the electric motor in the present invention is preferably the so-called electric generator with the above-mentioned power generation function, it can also be a structure provided with a motor that outputs driving torque and a generator that generates electricity during regenerative braking. In addition, although the accelerator mechanism in the present invention is usually composed of the above-mentioned accelerator pedal 12 and its sensor 13 as the main body, the mechanism directly operated by the driver can also be a mechanism other than the pedal. Moreover, although the clutch mechanism in the present invention is usually composed of the above-mentioned clutch pedal 18 and its sensor 20 as the main body, the mechanism directly operated by the driver can also be a mechanism other than the pedal. In addition, the rotation speed used to calculate the gear (speed ratio) is not limited to the above-mentioned transmission shaft rotation speed, and it can be a rotation speed of a suitable rotating component corresponding to the vehicle speed.

[0093] On the other hand, regarding the modes selected by the shift mechanism in the present invention, the speed gear (speed ratio) in a manual transmission vehicle is used as an example. Since the electric vehicle targeted by the present invention does not have a transmission, it is sometimes difficult to set a fixed speed gear (speed ratio) as in a manual transmission vehicle. Therefore, the modes in the present invention may also include a control state that includes speed gears (speed ratios) and enables travel at a predetermined range of speed ratios centered around a predetermined speed ratio. Furthermore, in the present invention, regarding the relaxation of the restriction that changes the upper limit value, the aforementioned heavy, medium, and light restrictions are prepared in advance. In addition to changing the upper limit value from heavy to medium or light, the upper limit value may be multiplied by a relaxation coefficient and the relaxation coefficient may be set to an appropriate value based on the temperature and SOC of the power storage device 3, or to a value corresponding to the hypothetical engine speed immediately before the gear shift.

Claims

1. A manual speed shift simulation control device for an electric vehicle, comprising: an electric motor as a driving force source; an accelerator mechanism, operated by a driver to increase or decrease the output of the electric motor; a power storage device, connected to the electric motor, and having at least one of a rate of change of output torque and an amount of power input and output limited; a clutch mechanism, operated by the driver to simulate an intermittent clutch operation for transmitting torque between the electric motor and drive wheels; and a shift mechanism, operated by the driver to select a mode representing the relationship between the output of the electric motor and the drive torque at the drive wheels. The manual transmission simulation control device for an electric vehicle is characterized in that: having a controller for controlling the torque of the electric motor, The controller is configured to perform torque control to change the output torque of the electric motor based on a detection signal of a shift operation, wherein the shift operation includes: intermittent simulation operation of the torque performed by the clutch mechanism; an output increase / decrease operation of the electric motor performed by the accelerator mechanism in association with the intermittent simulation operation; and a mode selection operation performed by the shift mechanism, The controller is configured to change a limit value of at least one of the output torque change rate and the power input / output amount in a direction to relax the limit when the output torque of the electric motor changes in association with the shift operation. The controller relaxes the restriction during a predetermined time after a simulated cutoff operation of cutting off the torque is performed by the clutch mechanism, or during a predetermined time after a simulated cutoff operation of transmitting the torque is performed by the clutch mechanism.

2. A manual speed shift simulation control device for an electric vehicle, comprising: an electric motor as a driving force source; an accelerator mechanism, operated by a driver to increase or decrease the output of the electric motor; a power storage device, connected to the electric motor, and having at least one of a rate of change of output torque and an amount of power input and output limited; a clutch mechanism, operated by the driver to simulate an intermittent clutch operation for transmitting torque between the electric motor and drive wheels; and a shift mechanism, operated by the driver to select a mode representing the relationship between the output of the electric motor and the drive torque at the drive wheels. The manual transmission simulation control device for an electric vehicle is characterized in that: having a controller for controlling the torque of the electric motor, The controller is configured to perform torque control to change the output torque of the electric motor based on a detection signal of a shift operation, wherein the shift operation includes: intermittent simulation operation of the torque performed by the clutch mechanism; an output increase / decrease operation of the electric motor performed by the accelerator mechanism in association with the intermittent simulation operation; and a mode selection operation performed by the shift mechanism, The controller is configured to change a limit value of at least one of the output torque change rate and the power input / output amount in a direction to relax the limit when the output torque of the electric motor changes in association with the shift operation. The controller determines whether a protection request for the electric motor or the power storage device is satisfied, and regulates relaxation of the restriction when the protection request is satisfied.

3. The manual shift simulation control device for an electric vehicle according to claim 2, wherein: The controller relaxes the restriction when a simulated cutoff operation for cutting off the torque is performed by the clutch mechanism, or a simulated cutoff operation for transmitting the torque is performed by the clutch mechanism.

4. The manual speed shift simulation control device for an electric vehicle according to claim 2, wherein: The controller relaxes the restriction during a predetermined time after a simulated cutoff operation of cutting off the torque is performed by the clutch mechanism, or during a predetermined time after a simulated cutoff operation of transmitting the torque is performed by the clutch mechanism.

5. The manual speed shift simulation control device for an electric vehicle according to claim 2, wherein: The controller is configured to include, as a control model, a virtual vehicle having a transmission whose speed ratio is switched by the shift mechanism and an engine connected to the transmission. The controller is configured to obtain a virtual engine speed based on a gear ratio assumed to be set by the transmission and a predetermined rotational speed corresponding to a vehicle speed of the electric vehicle. The controller is configured to relax the restriction when the virtual engine speed is equal to or higher than a predetermined reference speed.

6. The manual shift simulation control device for an electric vehicle according to any one of claims 2 to 5, characterized in that: The controller regulates the relaxation of the restriction so that the change of the restriction value in the direction of relaxing the restriction when performing a cut-off simulation operation of cutting off the torque through the clutch mechanism takes precedence over the change of the restriction value in the direction of relaxing the restriction when performing a connection simulation operation of transmitting the torque through the clutch mechanism.

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