Brake indicator system

Abstract

To make it possible to grasp a distribution state of brake torque of each of a regenerative brake and a friction brake without using visual information.SOLUTION: A brake indicator system includes: CPU 44A (drive processor) and CPU 46A (acoustic processor). CPU44A distributes a brake torque request value Tr _brk* to a vehicle 100 to a regenerative brake torque command value Tr _rbrk and a friction brake torque command value Tr _fbrk. The CPU 46A generates acoustic signals SI_1 and SI_2 corresponding to a difference ΔTr between the regenerative brake torque command value Tr _rbrk and the friction brake torque command value Tr _fbrk.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Disclosed herein is a brake indicator system that signals braking conditions. [Background technology]

[0002] For example, Patent Document 1 discloses a pseudo-sound generating device that outputs a pseudo-sound corresponding to the driving conditions of a vehicle. The driving conditions include acceleration, vehicle speed, accelerator operation amount, steering angle, brake operation amount, electric motor drive amount, internal combustion engine drive amount, and wheel slip amount. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-105923 Summary of the Invention [Problem to be solved by the invention]

[0004] In some cases, a vehicle is equipped with a rotating electric machine as a drive source, and in such cases, the vehicle is equipped with a regenerative brake and a friction brake as braking mechanisms.

[0005] By increasing the proportion of regenerative braking, the decrease in the battery SOC can be suppressed. To increase the proportion of regenerative braking torque, braking that maximizes regenerative braking torque is required while preventing the braking torque from being distributed to friction braking torque.

[0006] Here, the regenerative braking torque and the friction braking torque may be displayed on a display such as an instrument panel. However, for example, during a race, frequently checking the display to check the regenerative braking torque and the friction braking torque may hinder smooth driving.

[0007] Therefore, this specification discloses a brake indicator system that allows the driver to grasp the distribution status of the brake torque between the regenerative brake and the friction brake without using visual information. [Means for solving the problem]

[0008] Disclosed herein is a brake indicator system including a drive train processor and an acoustic processor. The drive train processor divides a vehicle brake torque request into a regenerative braking torque command and a friction braking torque command. The acoustic processor generates an acoustic signal corresponding to the difference between the regenerative braking torque command and the friction braking torque command.

[0009] According to the above configuration, by listening to the indicating sound in the form of an acoustic signal, it is possible to grasp the distribution status of the regenerative brake torque command value and the friction brake torque command value.

[0010] In the above configuration, the acoustic processor may increase the volume value of the acoustic signal as the difference obtained by subtracting the friction brake torque command value from the regenerative brake torque command value increases.

[0011] According to the above configuration, the magnitude of the regenerative braking torque can be grasped according to the volume of the indicator sound.

[0012] In the above configuration, the acoustic processor may cause the power spectrum of the acoustic signal to differ depending on whether the difference is positive or negative.

[0013] According to the above configuration, the tone of the indicator sound changes depending on whether the difference obtained by subtracting the friction brake torque command value from the regenerative brake torque command value is positive or negative. The tone of the indicator sound can be used to determine whether the regenerative brake or the friction brake is dominant.

[0014] In the above configuration, the acoustic processor may increase the pitch of the acoustic signal as the difference obtained by subtracting the friction brake torque command value from the regenerative brake torque command value increases.

[0015] According to the above configuration, the magnitude of the regenerative braking torque can be grasped according to the pitch of the indicator sound.

[0016] In the above configuration, the acoustic processor may be switchable between an actual operation mode and a training mode. In the actual operation mode, the acoustic processor receives a regenerative braking torque command value and a friction braking torque command value. In the training mode, the acoustic processor receives a brake torque request value, which is a value before being distributed to the regenerative braking torque command value and the friction braking torque command value. The brake indicator system further includes a setting unit. An upper limit value for the regenerative braking torque command value in the training mode can be set by the setting unit. In the training mode, the acoustic processor distributes the brake torque request value to the regenerative braking torque command value and the friction braking torque command value based on the set upper limit value. Furthermore, the acoustic processor generates an acoustic signal based on the regenerative braking torque command value and the friction braking torque command value.

[0017] For example, when the battery is fully charged, the upper limit of the regenerative braking torque command value is 0 [kW]. Even in such a case, it is possible to practice braking to maximize the regenerative braking torque. [Effects of the Invention]

[0018] According to the brake indicator system of the present specification, the distribution status of the brake torque between the regenerative brake and the friction brake can be grasped without using visual information. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram illustrating a hardware configuration of a brake indicator system according to an embodiment of the present invention; [Figure 2] FIG. 4 is a diagram illustrating an example of an indicator sound control flow according to the first embodiment (volume control). [Figure 3]4 is a diagram illustrating a time chart of a brake pedal stroke and an indicator sound according to the first embodiment. FIG. [Figure 4] FIG. 10 is a diagram illustrating an example of an indicator sound control flow when two types of indicator sounds are used. [Figure 5] FIG. 10 is a diagram illustrating a time chart of a brake pedal stroke and an indicator sound in an indicator sound control flow when two types of indicator sounds are used. [Figure 6] FIG. 2 is a diagram illustrating an example of the power spectrum of an acoustic signal SI_1 (first acoustic signal). [Figure 7] FIG. 10 is a diagram illustrating an example of the power spectrum of an acoustic signal SI_2 (second acoustic signal). [Figure 8] FIG. 10 is a diagram illustrating an example of an instruction sound control flow according to the second embodiment (pitch control). [Figure 9] FIG. 10 is a diagram illustrating a time chart of a brake pedal stroke and an indicator sound in an indicator sound control flow according to the second embodiment. [Figure 10] 10 is a graph illustrating an example of the relationship between regenerative torque and the volume of an indicator sound in the indicator sound control flow according to the third embodiment (volume and pitch control). [Figure 11] 10 is a graph illustrating an example of the relationship between the battery temperature and the pitch of an indicator sound in the indicator sound control flow according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] 1. Overall structure Fig. 1 illustrates an example of the overall configuration of a vehicle 100. The vehicle 100 is equipped with a brake indicator system according to this embodiment. Note that Fig. 1 mainly illustrates devices related to the brake indicator system. Devices less related to the system are omitted from the illustration as appropriate.

[0021] As will be described later, the brake indicator system according to this embodiment is an acoustic indicator system. That is, fluctuations in regenerative braking torque and friction braking torque can be grasped by an indicator sound. The indicator sound is emitted from a speaker 33. The brake indicator system according to this embodiment includes a display device 30, a speaker 33, a CGW-ECU 40, a battery ECU 42, a powertrain / chassis ECU 44, an audio ECU 46, and a brake pedal sensor 83.

[0022] The vehicle 100 includes, for example, a rotating electric machine 11 as a drive source. The vehicle 100 may be an electric vehicle (BEV, Battery Electric Vehicle). Alternatively, the vehicle 100 may be a hybrid vehicle (HEV) or a plug-in hybrid vehicle (PHEV).

[0023] The vehicle 100 includes a battery 10, a step-up / step-down DC / DC converter 12, an inverter 13, and a rotating electric machine 11 as high-voltage circuits. During power running, the DC power output from the battery 10 is boosted by the step-up / step-down DC / DC converter 12. The boosted power is then subjected to AC conversion by the inverter 13. The converted AC power is supplied to the rotating electric machine 11, thereby driving the rotating electric machine 11. The driving force is then transmitted to drive wheels 16.

[0024] During regeneration, the rotating electric machine 11 is driven by the drive wheels 16. This regenerative driving decelerates the vehicle 100. The regenerative driving causes the rotating electric machine 11 to generate electricity. The AC power obtained from the rotating electric machine 11 is converted to DC by the inverter 13. The converted DC power is then stepped down by the step-up / step-down DC / DC converter 12. The stepped-down DC power is supplied to the battery 10. This charges the battery 10.

[0025] The vehicle 100 is also provided with a steering wheel 70, an accelerator pedal 80, and a brake pedal 82. The stroke amount of the accelerator pedal 80 is detected by an accelerator pedal sensor 81. The stroke amount of the brake pedal 82 is detected by a brake pedal sensor 83. These operation amounts are transmitted to the CGW-ECU 40 as, for example, electrical signals. In response to these, the CGW-ECU 40 transmits drive commands and steering commands to the powertrain / chassis ECU 44.

[0026] The vehicle 100 is further provided with a friction brake mechanism 15. The friction brake mechanism includes a brake booster and a brake disc, which are not shown.

[0027] 2. ECU As illustrated in Fig. 1, a vehicle 100 is provided with a plurality of electronic control units (ECUs). These electronic control units are provided, for example, for each function of the vehicle 100. For example, the vehicle 100 includes a battery ECU 42, a powertrain / chassis ECU 44, and an audio ECU 46. Furthermore, the vehicle 100 is provided with a central gateway ECU 40 (hereinafter referred to as CGW-ECU as appropriate). The CGW-ECU 40 is a host ECU that integrates the above-mentioned functional ECUs.

[0028] 1, each of the functional ECUs and the CGW-ECU 40 is configured by a computer. These ECUs include CPUs 40A, 42A, 44A, and 46A, RAMs 40B, 42B, 44B, and 46B, storages 40C, 42C, 44C, and 46C, input / output controllers 40D, 42D, 44D, and 46D, and ROMs 40E, 42E, 44E, and 46E. These devices can communicate with each other via an internal bus (not shown).

[0029] The input / output controllers 40D, 42D, 44D, and 46D receive signals output from various sensors and ECUs mounted on the vehicle 100. The input / output controllers 40D, 42D, 44D, and 46D also output drive commands to on-board devices such as actuators. The CPUs 40A, 42A, 44A, and 46A are processors that perform calculations based on signals received from the input / output controllers 40D, 42D, 44D, and 46D. The CPUs 40A, 42A, 44A, and 46A also generate drive commands for the devices to be controlled.

[0030] The CPU 44A of the powertrain / chassis ECU 44 will be referred to as a drive system processor hereinafter, and the CPU 46A of the audio ECU 46 will be referred to as an audio system processor hereinafter.

[0031] Control programs are stored in storage devices such as RAM 40B, 42B, 44B, and 46B, storage devices 40C, 42C, 44C, and 46C, and ROM 40E, 42E, 44E, and 46E. These storage devices also store data detected by sensors. These storage devices also store the upper limit value Tr_rbrk_max of the regenerative braking torque command value set by display device 30 (setting unit).

[0032] The CPUs 40A, 42A, 44A, and 46A execute the control programs stored in the storages 40C, 42C, 44C, and 46C and the ROMs 40E, 42E, 44E, and 46E, thereby enabling the indicator sound control flow as illustrated in FIG. 2 to be executed.

[0033] For any of the above ECUs, the control program may be stored in a non-transitory computer-readable storage medium such as a DVD, instead of being stored in a storage device or a ROM. The CPU can read the storage medium to execute the indicator sound control flow shown in Figure 2.

[0034] When executing the indicator sound control flow, the battery ECU 42 obtains an upper limit value Win of regenerative power. The battery ECU 42 acquires data on battery current Ib from a current sensor 10A. The battery ECU 42 also acquires data on battery voltage Vb from a voltage sensor 10B. The battery ECU 42 also acquires data on battery temperature Tb from a temperature sensor 10C.

[0035] The battery ECU 42 determines the upper limit value Win of the regenerative power based on the battery current Ib, the battery voltage Vb, and the battery temperature Tb. For example, the battery ECU 42 stores a table (map) in which the battery current Ib, the battery voltage Vb, and the battery temperature Tb are used as input values ​​and the upper limit value Win is used as an output value.

[0036] Qualitatively, the lower the SOC of the battery 10, the higher the upper limit value Win is set. When the battery 10 is fully charged, the upper limit value Win is set to 0 [kW]. Furthermore, the higher the temperature Tb of the battery 10, the lower the upper limit value Win is set. The calculated upper limit value Win is transmitted to the CGW-ECU 40.

[0037] The CGW-ECU 40 transmits an upper limit value Win of the regenerative power to the powertrain-chassis ECU 44. The CGW-ECU 40 also transmits a stroke amount St_brk of the brake pedal 82 to the powertrain-chassis ECU 44.

[0038] For example, the brake pedal sensor 83 detects the stroke amount St_brk of the brake pedal 82. The detected stroke amount St_brk is transmitted to the powertrain-chassis ECU 44 via the CGW-ECU 40.

[0039] The powertrain-chassis ECU 44 calculates a brake torque request value Tr_brk* based on the stroke amount St_brk. The brake torque request value Tr_brk* is a braking request value from the driver for the vehicle 100. For example, the brake torque request value Tr_brk* is directly proportional to the stroke amount St_brk of the brake pedal 82.

[0040] Furthermore, the powertrain-chassis ECU 44 distributes the brake torque request value Tr_brk* into a regenerative brake torque command value Tr_rbrk and a friction brake torque command value Tr_fbrk. Based on the distributed regenerative brake torque command value Tr_rbrk, a PWM signal is generated for the inverter 13. Based on the distributed friction brake torque command value Tr_fbrk, the output of the friction brake mechanism 15 (e.g., a brake booster) is controlled.

[0041] For example, the powertrain / chassis ECU 44 calculates a regenerative brake torque command value Tr_rbrk based on the brake torque request value Tr_brk* and the upper limit value Win of the regenerative power. For example, the powertrain / chassis ECU 44 stores a table (map) that defines the correspondence relationship between the brake torque request value Tr_brk* and the regenerative power.

[0042] The table sets the maximum regenerative brake torque command value Tr_Brk_max corresponding to the upper limit value Win of regenerative power. If the brake torque request value Tr_brk* is equal to or less than the maximum regenerative brake torque command value Tr_Brk_max, the brake torque request value Tr_brk* is 100% covered by the regenerative brake torque.

[0043] On the other hand, if the brake torque request value Tr_brk* exceeds the maximum value Tr_Brk_max of the regenerative brake torque command value, the difference obtained by subtracting the maximum value Tr_Brk_max of the regenerative brake torque command value from the brake torque request value Tr_brk* is distributed to the friction brake torque command value Tr_fbrk.

[0044] The audio ECU 46 controls the video and audio of the display device 30. The audio ECU 46 also controls the audio of the speaker 33. As will be described later, the audio ECU 46 outputs an instruction sound from the speaker 33. By listening to the instruction sound, the driver can understand the distribution status of the brake torque between the regenerative brake and the friction brake.

[0045] The display device 30 is installed, for example, on an instrument panel (not shown) of the vehicle 100. The display device 30 includes a display unit and a setting unit. For example, the display device 30 is configured with a touch panel that has the functions of the display unit and the setting unit.

[0046] The driver performs various operations through the display device 30. For example, by operating the display device 30, the driver can switch on / off a training mode, which will be described later. Furthermore, an upper limit value Tr_rbrk_max of the regenerative braking torque command value used in the training mode is set through the display device 30. This upper limit value Tr_rbrk_max differs from the actual upper limit value. In other words, the upper limit value Tr_rbrk_max is set as a temporary value for training purposes.

[0047] 3-1. Indicative sound control flow (first embodiment, volume control using a single sound) The indicator sound control flow according to the first embodiment will be described with reference to Figures 1 to 3. With reference to Figures 1 and 2, the CPU 44A (drive system processor) of the powertrain / chassis ECU 44 acquires the brake pedal stroke St_brk from the brake pedal sensor 83. Furthermore, the CPU 44A uses the above-mentioned table (map) to determine the brake torque request value Tr_brk* corresponding to the brake pedal stroke St_brk (S10).

[0048] Next, the CPU 44A acquires an upper limit value Win of the regenerative power (S12). For example, the upper limit value Win is transmitted from the battery ECU 42 to the powertrain-chassis ECU 44 via the CGW-ECU 40. Next, the CPU 44A distributes the brake torque request value Tr_brk* into a regenerative brake torque command value Tr_rbrk and a friction brake torque command value Tr_fbrk in accordance with the upper limit value Win (S14). This distribution process has been described above, and therefore will not be described here.

[0049] The regenerative brake torque command value Tr_rbrk and the friction brake torque command value Tr_fbrk are transmitted to the audio ECU 46. A CPU 46A (acoustic system processor) of the audio ECU 46 obtains a difference value ΔTr by subtracting the friction brake torque command value Tr_fbrk from the regenerative brake torque command value Tr_rbrk. Furthermore, the CPU 46A determines whether the difference value ΔTr is equal to or greater than 0 (S16).

[0050] If the difference value ΔTr is a negative value, the instruction sound is not output from the speaker 33, and the flow returns to the starting point. On the other hand, if the difference value ΔTr is 0 or greater, the CPU 46A sets the first acoustic signal SI_1 in accordance with the difference value ΔTr (S18). For example, the larger the ΔTr is, the larger the volume value of the acoustic signal SI_1 is set by the CPU 46A.

[0051] For example, the volume value of the sound signal SI_1 may be set in direct proportion to ΔTr. Alternatively, the volume value of the sound signal SI_1 may be set in proportion to the square of ΔTr. Furthermore, the volume value of the sound signal SI_1 may be set in inverse proportion to ΔTr.

[0052] The first acoustic signal SI_1 is transmitted to the speaker 33. The speaker 33 emits an indicator sound at a volume corresponding to the first acoustic signal SI_1. FIG. 3 shows an example of a time chart of the brake pedal stroke and the indicator sound. The upper part of FIG. 3 shows the change in the brake pedal stroke over time. The horizontal axis represents time. The vertical axis represents the brake pedal stroke. The lower part of FIG. 3 shows the change in the indicator sound over time. The horizontal axis represents time. The vertical axis represents the volume [dB] of the indicator sound.

[0053] From time t1 to time t3, the entire brake torque request value Tr_brk* is supplied by the regenerative brake torque command value Tr_rbrk. In particular, from time t2 to time t3, the regenerative brake torque command value Tr_rbrk is set to the upper limit value Tr_rbrk_max. Therefore, the indicator sound is emitted at the maximum volume Imax.

[0054] After time t3, the brake pedal stroke further increases. That is, the brake torque request value Tr_brk* is distributed to the regenerative brake torque command value Tr_rbrk and the friction brake torque command value Tr_fbrk. At time t4, the difference value ΔTr becomes 0, and the warning sound is stopped. Furthermore, after time t4, the difference value ΔTr becomes a negative value. Therefore, the warning sound continues not to be emitted.

[0055] As described above, in the brake indicator system according to this embodiment, the CPU 46A (acoustic processor) generates an acoustic signal according to the difference value ΔTr obtained by subtracting the friction brake torque command value Tr_fbrk from the regenerative brake torque command value Tr_rbrk.

[0056] In motorsports scenes such as circuit racing, the driver wears a helmet. Furthermore, wind noise from the vehicle 100 traveling at high speeds may make it difficult for the driver to hear the instruction sound. Therefore, instead of or in addition to the speaker 33, the instruction sound may be output from headphones or earphones.

[0057] 3-2. Indicative sound control flow (modification of the first embodiment, volume control using two types of indicator sounds) 4 and 5 show a modified example of the first embodiment. In this example, when the difference value ΔTr is negative, the magnitude of the friction brake torque can be perceived as an acoustic signal. The CPU 46A also differentiates the power spectrum of the acoustic signal between when the difference value ΔTr is positive and when it is negative.

[0058] In the examples of Figures 4 and 5, two types of acoustic signals SI_1 and SI_2 are used. Note that in Figures 4 and 5, components with the same reference numerals as those in Figures 2 and 3 have the same functions. Therefore, the description of such components will be omitted below as appropriate.

[0059] Referring to FIG. 4, if the difference value ΔTr is negative in step S16, the CPU 46A sets the volume of the second acoustic signal SI_2 based on |ΔTr| (S19).

[0060] 5, the instruction sound generated by the first acoustic signal SI_1 disappears at time t4. After time t4, the instruction sound generated by the second acoustic signal SI_2 is emitted from the speaker 33. Then, as the friction brake torque command value Tr_fbrk increases (i.e., as the absolute value of the difference value |ΔTr| increases), the volume of the instruction sound generated by the second acoustic signal SI_2 increases.

[0061] The indicator sound generated by the first acoustic signal SI_1 and the indicator sound generated by the second acoustic signal SI_2 have different timbres. In other words, the power spectra of the first acoustic signal SI_1 and the second acoustic signal SI_2 are different. FIG. 6 shows an example of the power spectrum of the first acoustic signal SI_1. The horizontal axis represents frequency [Hz], and the vertical axis represents the intensity of each frequency component.

[0062] The indicator sound generated by the first acoustic signal SI_1 is also called the eco-brake sound. The indicator sound generated by the first acoustic signal SI_1 is composed of a fundamental frequency f0 and its integer harmonics (2f0, 3f0, 4f0, 5f0, 6f0) combined together. The output of such a harmonic tone provides an incentive to use regenerative braking more effectively.

[0063] FIG. 7 illustrates the power spectrum of the second acoustic signal SI_2. The indicator sound of the second acoustic signal SI_2 includes the fundamental frequency f0 and its integer harmonics as well as non-integer harmonics. The synthesis of adjacent frequency components produces a so-called beat (hum) in the synthesized sound. Beats are known to cause discomfort and an unnatural feeling. By adding a warning nuance to the indicator sound, a driver is motivated to suppress friction braking. For example, the stroke of the brake pedal can be reduced to prevent the second acoustic signal SI_2 from humming.

[0064] 4-1. Indicative sound control flow (second embodiment, pitch control) In the examples of FIGS. 2 to 5, the volume of the instruction sound is adjusted by the difference value ΔTr. Instead of the volume, the pitch of the instruction sound may be adjusted. For example, in steps S18 and S19 of FIGS. 2 and 4, the volume is changed to the pitch. Furthermore, in the graphs at the bottom of FIGS. 3 and 5, the vertical axis is changed from volume [dB] to pitch [Hz]. In this case, for example, the larger the difference value ΔTr, the higher the CPU 46A raises the pitch of the audio signal SI_1. Furthermore, the larger the absolute value |ΔTr| of the difference value, the higher the CPU 46A raises the pitch of the audio signal SI_2.

[0065] 4-2. Indicative sound control flow (modification of the second embodiment, up and down changes from the reference sound) Figures 8 and 9 show modified examples of the second embodiment. In Figures 8 and 9, components with the same reference numerals as those in Figures 2 and 3 have the same functions. Therefore, in the following, descriptions of such components will be omitted as appropriate.

[0066] 8, in this control flow, an indicator sound is always emitted from speaker 33. That is, CPU 46A generates sound signal SI_1 regardless of whether difference value ΔTr is a positive value, 0, or a negative value.

[0067] 9, when the difference value ΔTr=0, the reference tone S0 is sounded from the speaker 33. When the difference value ΔTr>0, an indicator tone higher than the reference tone S0 is sounded. When the difference value ΔTr<0, an indicator tone lower than the reference tone S0 is sounded.

[0068] 5. Indicative sound control flow (third embodiment, combination of volume and pitch) 2 to 9, the vehicle state is notified to the driver by changing either the volume or the pitch of the indicator sound. Alternatively, the vehicle state may be notified to the driver by changing the volume or the pitch of the indicator sound.

[0069] For example, the volume [dB] of the indicator sound is determined in accordance with the difference value ΔTr as shown in Fig. 10. In other words, in this figure, the same control as in Figs. 3 and 5 is executed.

[0070] 11, the pitch [Hz] of the indicator sound is determined, for example, according to the temperature Tb of battery 10. For example, the temperature Tb and the pitch of the indicator sound are proportional to each other.

[0071] For example, as the temperature Tb of the battery 10 increases, the upper limit Win of the regenerative power is reduced. Accordingly, the upper limit Tr_rbrk_max of the regenerative brake torque is also reduced. Therefore, even if the brake pedal stroke is constant, if the pitch of the indicator sound gradually increases (as the temperature Tb of the battery 10 increases), the volume of the indicator sound changes. In this way, more appropriate braking is possible when information other than the brake pedal stroke is included in the indicator sound.

[0072] The vehicle state parameter to be associated with the pitch of the indicator sound is not limited to the temperature Tb of the battery 10. For example, the pitch of the indicator sound may be associated with tire pressure, tire temperature, SOC of the battery 10, outside air temperature, etc.

[0073] 6. Training Mode In the embodiments of Figures 2 to 11, the indicator sounds are emitted in conjunction with the actual regenerative braking torque and friction braking torque. However, the indicator sounds may be emitted based on fictitious regenerative braking torque and friction braking torque, independent of the actual regenerative braking torque and friction braking torque. The operating mode in which the indicator sounds are emitted based on the fictitious regenerative braking torque and friction braking torque is called a training mode.

[0074] In the training mode, the processes from step S12 onward in the flows of FIGS. 2, 4 and 8 are executed by the CPU 46A, which is an acoustic processor.

[0075] 1, the display device 30 (setting unit) can switch the training mode on / off. When the training mode is set to off, the actual operation mode is executed as illustrated in the embodiments of FIGS. 2 to 11.

[0076] In the actual operation mode, as described above, the CPU 46A (acoustic system processor) receives the regenerative brake torque command value Tr_rbrk and the friction brake torque command value Tr_fbrk from the CPU 44A (drive system processor) of the powertrain-chassis ECU 44. Then, the CPU 46A causes the speaker 33 to emit an instruction sound based on the regenerative brake torque command value Tr_rbrk and the friction brake torque command value Tr_fbrk.

[0077] When the training mode is set to ON, the brake torque request value Tr_brk* is transmitted to the CPU 46A from the CPU 44A of the powertrain-chassis ECU 44. In other words, the request value before being distributed to the regenerative brake torque command value Tr_rbrk and the friction brake torque command value Tr_fbrk is transmitted to the CPU 46A (acoustic system processor).

[0078] When the training mode is set to ON, the audio ECU 46 requests the display device 30 (setting unit) to set a virtual value for the upper limit value Tr_rbrk_max of the regenerative brake torque command value. The display device 30 displays a screen requesting the setting of the virtual value.

[0079] The virtual value setting assistance function may be provided in the display device 30. In other words, the virtual value of the upper limit value Tr_rbrk_max of the regenerative brake torque command value is indirectly set by the driver.

[0080] For example, a box for inputting the SOC of the battery 10 is displayed on the display device 30. The driver inputs an SOC suitable for training (for example, 50%). Then, for the battery 10 at an optimum temperature, the CPU 46A calculates an upper limit value Win of the regenerative power according to the input SOC. Furthermore, the CPU 46A calculates an upper limit value Tr_rbrk_max of the regenerative brake torque command value according to the upper limit value Win.

[0081] Based on the upper limit value Tr_rbrk_max (fictitious value) of the regenerative brake torque command value, the CPU 46A distributes the brake torque request value Tr_brk* (actual value) to the regenerative brake torque command value Tr_rbrk and the friction brake torque command value Tr_fbrk. The distributed regenerative brake torque command value Tr_rbrk and the friction brake torque command value Tr_fbrk are virtual values. The CPU 46A generates sound signals SI_1 and SI_2 based on these virtual values. Furthermore, an instruction sound is output from the speaker 33 based on the sound signals SI_1 and SI_2.

[0082] For example, when the battery 10 is fully charged, the brake torque request value Tr_brk* is entirely assigned to the friction brake torque command value Tr_fbrk. According to the above configuration, even in such a case, virtual braking training can be performed. [Explanation of symbols]

[0083] 10 Battery, 11 Rotating electric machine, 30 Display device, 33 Speaker, 40 Central gateway (CGW-) ECU, 42 Battery ECU, 44 Powertrain / chassis ECU, 44A CPU (drive system processor), 46 Audio ECU, 46A CPU (acoustic system processor), 82 Brake pedal, 83 Brake pedal sensor, 100 Vehicle.

Claims

1. a drive train processor that divides a brake torque request value for the vehicle into a regenerative brake torque command value and a friction brake torque command value; an acoustic processor that generates an acoustic signal according to a difference between the regenerative brake torque command value and the friction brake torque command value; Equipped with Brake indicator system.

2. 2. A brake indicator system according to claim 1, comprising: the acoustic processor increases the volume value of the acoustic signal as the difference obtained by subtracting the friction brake torque command value from the regenerative brake torque command value increases. Brake indicator system.

3. 3. A brake indicator system according to claim 2, comprising: the acoustic processor causes the power spectrum of the acoustic signal to differ depending on whether the difference is positive or negative. Brake indicator system.

4. 2. A brake indicator system according to claim 1, comprising: the acoustic processor increases the pitch of the acoustic signal as the difference obtained by subtracting the friction brake torque command value from the regenerative brake torque command value increases. Brake indicator system.

5. 2. A brake indicator system according to claim 1, comprising: the acoustic processor is switchable between an actual operation mode in which the regenerative brake torque command value and the friction brake torque command value are received, and a training mode in which the brake torque request value is received, a setting unit capable of setting an upper limit value of the regenerative braking torque command value in the training mode, the acoustic processor, in the training mode, distributes the brake torque request value to the regenerative brake torque command value and the friction brake torque command value based on the set upper limit value, and generates the acoustic signal. Brake indicator system.

Images