Driving system

Abstract

To allow a user to more reliably recognize a change in torque for each change of one time of a shift range.SOLUTION: A driving system includes: a motor that drives a drive shaft connected to an axle; a shift device that outputs a range change signal when a shift range is changed by driver's operation; and a control device that controls the motor so that a torque based on the changed shift range is output when the range change signal is input from the shift device. The control device prohibits input of the range change signal from the shift device at least from a time the shift range is changed until the torque based on the changed shift range is output to the drive shaft.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a drive device. [Background technology]

[0002] Conventionally, as this type of drive device, one that has been proposed is one that includes a motor that drives a drive shaft connected to an axle, and a shift lever that allows the driver to select a shift range (see, for example, Patent Document 1). In this drive device, the motor is controlled so that a target torque based on the currently selected shift range is output. Then, when the shift lever is operated and a change in the shift range is detected, the motor is controlled so that a torque that has been subjected to first-order delay processing with a predetermined gain for a post-change target torque based on the post-change shift range is output. This is said to be able to suppress shock when changing the shift range. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-77585 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned drive device, when the shift lever is operated to change the shift range, it takes time for the torque corresponding to the changed shift range to be output to the drive shaft. Therefore, when the shift range is changed consecutively, the torque output from the drive shaft changes before the user recognizes the torque change due to the first shift range change, which gives the user a sense of discomfort.

[0005] A main object of the drive device of the present disclosure is to allow a user to more reliably recognize a change in torque each time the shift range is changed. [Means for solving the problem]

[0006] The driving device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The drive device of the present disclosure is A motor that drives a drive shaft connected to the axle; a shift device that outputs a range change signal when a shift range is changed by an operation by a driver; a control device that executes a shift change time control to control the motor when the range change signal is input from the shift device so that a torque based on the changed shift range is output; A drive device comprising: The control device prohibits the input of the range change signal from the shift device at least from when the shift range is changed until when a torque based on the changed shift range is output to the drive shaft. The gist of the present invention is as follows.

[0008] In the drive device disclosed herein, input of a range change signal from the shift device is prohibited from when the shift range is changed until torque based on the changed shift range is output to the drive shaft. When the shift device is operated, acceptance of a range change signal from the shift device is prohibited until torque based on the changed shift range is output to the drive shaft. Therefore, when the shift range is changed consecutively by the driver's operation, the next shift change control is not executed until torque based on the shift range after one change is output to the drive shaft. As a result, the user can more reliably recognize the change in torque for each change of the shift range. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing the schematic configuration of an electric vehicle 20. FIG. [Diagram 2] 4 is a flowchart showing an example of a downshift processing routine. [Diagram 3] 6 is a graph showing whether a downshift signal is input and a change in drive shaft torque over time; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram showing the configuration of an electric vehicle 20 equipped with a drive device of the present embodiment. As shown in the figure, the electric vehicle 20 includes a motor 32 for running, an inverter 34, a battery 36, an electronic control unit (control device, hereinafter referred to as "ECU") 50, and a shift lever (shift device) 61.

[0011] The motor 32 is configured as a three-phase AC motor and includes a rotor having a permanent magnet embedded in a rotor core and a stator having a three-phase coil wound around the stator core. The rotor of the motor 32 is connected to a drive shaft 26 that is connected to the drive wheels 22a, 22b via a differential gear 24.

[0012] The inverter 34 is used to drive the motor 32. The inverter 34 is connected to the battery 36 via a power line 38, and has six transistors T11-T16 as switching elements, and six diodes D11-D16 connected in parallel to the six transistors T11-T16, respectively. The transistors T11-T16 are arranged in pairs, two at a time, so as to be on the source side and the sink side of the positive and negative lines of the power line 38, respectively. The connection points of the two transistors in each pair are connected to the coils of the corresponding phases (U-phase, V-phase, W-phase) of the motor 32. Therefore, when a voltage is applied to the inverter 34, the ECU 50 adjusts the ratio of the on-time of the paired transistors T11-T16, thereby forming a rotating magnetic field in the three-phase coils, and the motor 32 is driven to rotate.

[0013] The battery 36 is configured as a lithium ion secondary battery or a nickel-hydrogen secondary battery, and is connected to the inverter 34 via a power line 38. A smoothing capacitor 39 is attached to the power line 38.

[0014] The ECU 50 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, and input / output ports. The ECU 50 receives inputs of the rotational position θm of the rotor of the motor 32 from the rotational position sensor 32a, the phase currents Iu and Iv of the U-phase and V-phase of the motor 32 from the current sensors 32u and 32v, the voltage Vb of the battery 36 from the voltage sensor 36a, the current Ib of the battery 36 from the current sensor 36b, and the voltage VL of the power line 38 (capacitor 39) from the voltage sensor 39a. The ECU 50 also receives inputs of a start signal from a start switch 60, a shift range SP that is the operation position of the shift lever 61 from a shift range sensor 62, an accelerator opening Acc that is the depression amount of the accelerator pedal 63 from an accelerator pedal sensor 64, and a brake pedal position BP that is the depression amount of the brake pedal 65 from a brake pedal sensor 66. The ECU 50 also receives inputs of a vehicle speed V from a vehicle speed sensor 67. Here, the shift range SP of the shift lever 61 includes a parking range (P range) used when parking, a reverse range (R range) for backward driving, a normal drive range (D range) for forward driving, a manual range (M range), and the like. The M range is also provided with a downshift range (- range) and an upshift range (+ range). The shift range SP is changed in the order of the third-speed range M3, the second-speed range M2, and the first-speed range L every time the shift lever 61 is operated to the downshift range. The shift range SP is changed in the order of the first-speed range L, the second-speed range M2, and the third-speed range M3 every time the shift lever 61 is operated to the upshift range. The ECU 50 receives a downshift signal (range change signal) from a downshift sensor (not shown) that detects the operation of the shift lever 61 to the downshift range, and an upshift signal from an upshift sensor that detects the operation of the shift lever 61 to the upshift range. A control signal to the motor 32 is output from the ECU 50.

[0015] In the electric vehicle 20 of the embodiment, the ECU 50 sets the torque command Tm* of the motor 32 so that the running torque (target torque) Td* required for running (required of the drive shaft 26) is output to the drive shaft 26, and controls the transistors T11 to T16 of the inverter 34 so that the motor 32 is driven by the torque command Tm*. Here, the running torque command Td* is set based on the shift range SP, the accelerator opening Acc, and the vehicle speed V. The running torque command Td* is set so that the shift range SP increases in the order of D range, 3rd range M3, 2nd range M2, and 1st range L, and is larger when the accelerator opening Acc is large compared to when it is small, and is larger when the vehicle speed V is small compared to when it is large. Through this control, the motor 32 is controlled so that the behavior of the torque output from the motor 32 based on the operation (shift operation) of the shift lever 61 by the driver runs as the behavior of the torque in an engine vehicle equipped with an engine and a manual transmission. In other words, it is possible to drive in a manner that simulates driving an engine vehicle equipped with an engine and a manual transmission, and the driver can feel as if he or she is driving an engine vehicle equipped with an engine and a manual transmission. Note that the P range and the R range are not the core of this disclosure, so detailed explanations will be omitted.

[0016] In the electric vehicle 20 of the embodiment, the ECU 50 executes downshift control when a downshift signal is input from a downshift sensor (not shown). In the downshift control, the ECU 50 sets the traveling torque requirement Td* based on the shift range SP, accelerator opening Acc, and vehicle speed V after the downshift, sets the torque command Tm* of the motor 32 so that the set traveling torque requirement Td* is output to the drive shaft 26, and controls the transistors T11 to T16 of the inverter 34 so that the motor 32 is driven by the torque command Tm*. In addition, the ECU 50 executes upshift control when an upshift signal is input from an upshift sensor (not shown). In the upshift control, the ECU 50 sets the traveling torque requirement Td* based on the shift range SP, accelerator opening Acc, and vehicle speed V after the upshift, sets the torque command Tm* of the motor 32 so that the set traveling torque requirement Td* is output to the drive shaft 26, and controls the transistors T11 to T16 of the inverter 34 so that the motor 32 is driven by the torque command Tm*.

[0017] Next, the operation of the electric vehicle 20 of this embodiment configured as described above, particularly the operation when the shift lever 61 is operated to the downshift range, will be described. Fig. 2 is a flowchart showing an example of a downshift processing routine executed by the ECU 50. This routine is executed when the shift range SP is changed by operating the shift lever 61 to the downshift range (for example, when the shift range SP is changed from the D range to the third range M3, or from the third range M3 to the second range M2, etc.).

[0018] When this routine is executed, the CPU of the ECU 50 starts measuring the elapsed time T1 from when execution of this routine is started (S100). Since this routine is executed when the shift range SP is changed, the elapsed time T1 is also the time that has elapsed since the shift range SP was changed.

[0019] Next, the above-mentioned downshift control is executed (S110), and the input of the downshift signal is prohibited (S120). When the input of the downshift signal is prohibited, the downshift control is not executed and the control of the motor 32 in the current shift range SP continues until the input of the downshift signal is permitted next time.

[0020] Next, a rise time Tup is set (S130), and the process waits until the elapsed time T1 exceeds the rise time Tup (S140). The rise time Tup is a time that is set in advance based on the output characteristics of the torque of the motor 32 as the time from when a downshift signal is input until the torque output to the drive shaft 26 by the downshift control increases (rises) to the running torque requirement Td* based on the shift range SP, accelerator opening Acc, and vehicle speed V after the downshift. The rise time Tup is set to, for example, 0.8 sec, 1.0 sec, 1.2 sec, etc. Therefore, S140 becomes a process of waiting until the torque output to the drive shaft 26 rises to the running torque requirement Td* after the downshift.

[0021] When the elapsed time T1 exceeds the rise time Tup in S140, it is determined that the torque output to the drive shaft 26 has risen to the running torque requirement Td* after the downshift, and measurement of the elapsed time T2 is started (S150), and the process waits until the elapsed time T2 exceeds the recognition time Tre (S160). The recognition time Tre is a predetermined time from when the torque output to the drive shaft 26 changes (rises) to when the user can reliably recognize the change (rise) of the torque. The recognition time Tre is set to, for example, 2 sec, 2.5 sec, 3 sec, etc.

[0022] When the elapsed time T2 exceeds the recognition time Tre in S160, it is determined that the user has certainly recognized the torque change, and the input of a downshift signal is permitted (S170), and this routine ends. When the input of a downshift signal is permitted, the next downshift control can be executed.

[0023] FIG. 3 is an explanatory diagram showing an example of a state in which the input of a downshift signal is permitted and a change in torque (drive shaft torque) output to the drive shaft 26 over time. When the shift lever 61 is operated to the downshift range, measurement of the elapsed time T1 is started, downshift control is executed, and input of the downshift signal is prohibited (time t0). When the elapsed time T1 exceeds the rise time Tup, the drive shaft torque rises to the running torque requirement Td* after the downshift and measurement of the elapsed time T2 is started (time t1). Since input of the downshift signal is prohibited during the period from time t0 to t1, even if the shift lever 61 is operated to the downshift range, downshift control using the shift range SP after a further downshift (hereinafter referred to as "next downshift control") is not executed. During the period from time t0 to t1, the drive shaft torque has not risen to the running torque requirement Td* after the downshift, so the user does not recognize the change in torque due to the downshift. By prohibiting the input of a downshift signal during the period from time t0 to t1 and not executing the next downshift control even if the shift lever 61 is operated to the downshift range, it is possible to prevent the next downshift control from being executed before the user recognizes the change in torque due to the downshift control of S110.

[0024] When the input of a downshift signal is thus prohibited, the input of a downshift signal is prohibited until the elapsed time T2 exceeds the recognition time Tre (times t1 to t2). Even if the drive shaft torque rises to the driving torque requirement Td* after the downshift, it may take some time for the user to recognize the change in torque due to the downshift. During the period from time t1 to t2, the input of a downshift signal is prohibited and downshift control is not executed even if the shift lever 61 is operated to the downshift range, thereby preventing the next downshift control from being executed before the user recognizes the change in torque due to the downshift control of S110.

[0025] When the elapsed time T2 exceeds the recognition time Tre, input of a downshift signal is permitted, enabling control at the next downshift (time t2). In this way, by prohibiting input of a downshift signal during the period from time t0 to t2, the user can be made more certain to recognize the change in torque with each change of the shift range SP. Furthermore, by permitting input of a downshift signal after time t2, control at the next downshift becomes possible. This process allows the user to be more certain to recognize the change in torque with each change of the shift range SP.

[0026] According to the electric vehicle 20 equipped with the drive unit of the present embodiment described above, the input of a downshift signal is prohibited at least from the time when the downshift range is operated to change the shift range SP until the torque based on the changed shift range SP is output to the drive shaft 26, thereby allowing the user to more reliably recognize the change in torque with each change of the shift range SP.

[0027] In the embodiment described above, input of a downshift signal is prohibited until the elapsed time T1 exceeds the rise time Tup and the elapsed time T2 exceeds the recognition time Tre. However, it is sufficient to prohibit input of a downshift signal at least until the elapsed time T1 exceeds the rise time Tup, and input of a downshift signal may be permitted immediately after the elapsed time T1 exceeds the rise time Tup.

[0028] In the above-described embodiment, the drive device of the present disclosure is applied when the shift lever 61 is operated to the downshift range, but it may also be applied when the torque to be output to the drive shaft 26 changes due to a change in the shift range SP, such as when the shift lever 61 is operated to the upshift range or from D range to M range.

[0029] The relationship between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be described below. In the embodiment, the motor 32 corresponds to the "motor", the shift lever 61 corresponds to the "shift device", and the ECU 50 corresponds to the "control device".

[0030] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the Means for Solving the Problem column.

[0031] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0032] The present disclosure is applicable to the drive device manufacturing industry and the like. [Explanation of symbols]

[0033] 32 Motor, 50 Electronic control unit (ECU), 61 Shift lever.

Claims

[Claim 1] A motor that drives a drive shaft connected to the axle; a shift device that outputs a range change signal when a shift range is changed by an operation by a driver; a control device that controls the motor when the range change signal is input from the shift device so that a torque based on the changed shift range is output; A drive device comprising: The control device prohibits the input of the range change signal from the shift device at least from when the shift range is changed until when a torque based on the changed shift range is output to the drive shaft. Drive unit.

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