Vehicle control device

Abstract

To provide a vehicle control device that can reduce noise which occurs when performing rectangular wave control of an electric motor.SOLUTION: A vehicle control device mounted on a vehicle configured such that a first drive source being an electric motor outputs torque to a first wheel, comprises: a storage part storing a first resonance map; and a control unit that calculates a first torque command value showing a value of torque that the first drive source is made to output. In the first resonance map, one or a plurality of operation points in which resonance occurs in an operation region of the first drive source to which rectangular wave control is performed, are shown as first resonance points (X1). When a predicted movement destination (k3) of an operation point (A) of the first drive source overlaps with the first resonance points (X1), the control unit decreases or increases the first torque command value so that the predicted movement destination avoids the first resonance points (X1).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] Cited Document 1 describes a system for controlling a rotating electric machine mounted on a vehicle, which switches between a control mode in which the rotating electric machine is driven with a sinusoidal current and a control mode in which the rotating electric machine is driven with a square wave voltage. In this system, the sinusoidal current control mode is used in the low speed range, and the square wave voltage control mode is used in the high speed range. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-081658 Summary of the Invention [Problem to be solved by the invention]

[0004] Because square wave voltages contain high-order harmonic components, when a vehicle's electric motor is driven with a square wave voltage, electrical resonance occurs in the electric motor and its surrounding area, which can cause noise in the vehicle.

[0005] An object of the present invention is to provide a vehicle control device that can reduce noise generated when an electric motor is subjected to square wave control. [Means for solving the problem]

[0006] A vehicle control device according to one aspect of the present invention includes: A vehicle control device mounted on a vehicle having a first drive source which is an electric motor and outputs torque to a first wheel, and a second drive source which is an electric motor and outputs torque to the first wheel or a second wheel different from the first wheel, a storage unit that stores a first resonance map and a second resonance map; a control unit that calculates a first torque command value indicating a value of torque to be output from the first drive source and a second torque command value indicating a value of torque to be output from the second drive source; Equipped with the first resonance map indicates, as first resonance points, one or more operating points at which resonance occurs in an operating region of the first drive source that is square wave controlled; the second resonance map indicates, as second resonance points, one or more operating points at which resonance occurs in an operating region of the second drive source that is square wave controlled; the control unit, when a predicted movement destination of the operating point of the first drive source coincides with the first resonance point, decreases or increases the first torque command value so as to avoid the first resonance point, and when decreasing the first torque command value so as to avoid the first resonance point, increases the second torque command value, and when increasing the first torque command value so as to avoid the first resonance point, decreases the second torque command value; components of the first resonance map include a rotation speed of the first drive source and a torque of the first drive source; components of the second resonance map include a rotation speed of the second drive source and a torque of the second drive source; the rotation speed of the first driving source is a value obtained by multiplying the rotation speed of the second driving source by a first ratio, The range of rotational speeds of the first driving source in which the first resonance point is located in the first resonance map does not overlap with the range obtained by multiplying the range of rotational speeds of the second driving source in which the second resonance point is located in the second resonance map by the first ratio. [Effects of the Invention]

[0007] According to the present invention, the resonant operating point is indicated by the first resonance map, and the control unit decreases or increases the first torque command so as to avoid the resonant operating point, thereby reducing resonance that occurs when the electric motor is subjected to rectangular wave control. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a vehicle equipped with a vehicle control device according to a first embodiment. [Figure 2] FIG. 4 is a diagram showing a first resonance map stored in a storage unit. [Figure 3] FIG. 2 is a diagram showing the configuration of a battery, an inverter, a first driving source, and peripheral circuits. [Figure 4] 4 is a diagram illustrating an example of the operation of the vehicle control device according to the first embodiment. FIG. [Figure 5] 10 is a flowchart showing a torque command value calculation process executed by a control unit. [Figure 6] FIG. 10 is a block diagram showing a vehicle equipped with a vehicle control device according to a second embodiment. [Figure 7A] 10 is a diagram for explaining the operation of the vehicle control device according to the second embodiment, showing an example of transition of the operating point of the first drive source. FIG. [Figure 7B] 10 is a diagram for explaining the operation of the vehicle control device according to the second embodiment, showing an example of transition of the operating point of the second drive source. FIG. [Figure 8A] 10 is a first part of a flowchart showing a torque command value calculation process executed by a control unit of the second embodiment. [Figure 8B] 10 is a second part of a flowchart showing the torque command value calculation process executed by the control unit of the second embodiment. [Figure 9] FIG. 10 is a block diagram showing a vehicle equipped with a vehicle control device according to a third embodiment. [Figure 10] FIG. 10 is a diagram showing a second resonance map stored in a storage unit. [Figure 11A] 10 is a diagram for explaining the operation of the vehicle control device according to the third embodiment, showing an example of transition of the operating point of the first drive source. FIG. [Figure 11B] 10 is a diagram for explaining the operation of the vehicle control device according to the third embodiment, showing an example of transition of the operating point of the second drive source. FIG. [Figure 12A] 11 is a first part of a flowchart showing a torque command value calculation process executed by a control unit of the third embodiment. [Figure 12B]13 is a third part of a flowchart showing the torque command value calculation process executed by the control unit of the third embodiment. [Figure 13] FIG. 10 is a block diagram showing a vehicle control device according to a fourth embodiment. [Figure 14] 10 is a flowchart showing a resonance map selection process executed by a control unit of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0010] (Embodiment 1) Fig. 1 is a block diagram showing a vehicle equipped with a vehicle control device according to embodiment 1. Fig. 2A is a diagram showing a first resonance map stored in a storage unit.

[0011] As shown in FIG. 1 , a vehicle control device 10 of the first embodiment is mounted on a vehicle 1 that has a first drive source 4, which is an electric motor. The first drive source 4 is sometimes subjected to square wave control and outputs torque to a first wheel 2A. The vehicle control device 10 has a storage unit 11 that stores a first resonance map M1, and a control unit 12 that calculates a first torque command value that indicates the value of the torque to be output by the first drive source 4. The vehicle 1 has a speed sensor 4a that directly or indirectly measures the rotational speed of the first drive source 4, and the measurement value of the speed sensor 4a is sent to the control unit 12. The vehicle 1 also has a driving operation unit 9, a battery 7, and an inverter 6.

[0012] 2, the first resonance map M1 indicates, as a first resonance point X1, one or more operating points at which resonance occurs in or around the first drive source 4 in an operating region R3 of the first drive source 4 when square wave control is performed. In FIG. 2, the first resonance point X1 is indicated by the symbol "*". The first resonance map M1 is created in advance based on tests, simulations, or the like, and is stored in the storage unit 11.

[0013] The operating region of the first driving source 4 is represented by a two-dimensional region whose components are the rotational speed of the first driving source 4 and the torque of the first driving source 4, and one point in this region corresponds to one operating point of the first driving source 4.

[0014] The operating region of the first drive source 4 includes an operating region R1 in which sine wave control is performed, an operating region R3 in which square wave control is performed, and an operating region R2 in which transitional control between sine wave control and square wave control is performed.

[0015] Sine wave control refers to control in which the inverter 6 outputs a sine wave current modulated by PWM (Pulse Width Modulation) through switching control to the first drive source 4, causing the first drive source 4 to perform powering or regenerative operation. Square wave control refers to control in which the inverter 6 outputs a square wave pulse voltage corresponding to the rotation phase of the first drive source 4, causing the first drive source 4 to perform powering operation. The square wave pulse voltage is generated by switching on and off the power semiconductor switch elements of the inverter 6 at the rise and fall times of the voltage. Transient control refers to control in which the inverter 6 outputs a current with a waveform distorted from a sine wave by performing control that exceeds the maximum amplitude of the sine wave current that can be PWM modulated, causing the first drive source 4 to perform powering operation.

[0016] The multiple first resonance points X1 shown in the first resonance map M1 are included in the operating region R3 where square wave control is performed. The first resonance points X1 are typically concentrated in a specific rotational speed range W1 within the operating region R3. The specific rotational speed range W1 in which the first resonance points X1 are concentrated may be only one or multiple. Furthermore, typically, the first resonance points X1 are located on the high torque side of the specific rotational speed range W1, and are often not located on the low torque side.

[0017] FIG. 3 is a diagram showing the configuration of the battery 7, inverter 6, first drive source 4, and their peripheral circuits. As shown in FIG. 3, inductances L1-L4 and L7-L9 are provided between the battery 7, inverter 6, first drive source 4, and their peripheral circuits (relay 3a, connectors 3b, 3c, etc.). The inverter 6 also includes inductances L5 and L6 and a capacitor C1 upstream of the switching circuit 6a. Therefore, the inductances L1-L9 and the capacitor C1 form a resonant circuit around the first drive source 4 and inverter 6, which may cause electrical resonance at a specific frequency. The first resonance point X1 shown in the first resonance map M1 is an operating point where the electrical resonance becomes a physical vibration and generates noise. The square-wave voltage contains high-order harmonic components, which makes the electrical resonance more likely to occur. For this reason, the first resonance point X1 is included in the operating region R3 where square-wave control is performed.

[0018] The control unit 12 is an ECU (Electronic Control Unit) that includes a CPU (Central Processing Unit) that performs calculation processing, a RAM (Random Access Memory) in which the CPU expands data, a ROM (Read Only Memory) that stores a control program executed by the CPU, and an interface that transmits and receives signals between the CPU and devices external to the control unit 12. The control unit 12 may be composed of one ECU, or may be composed of multiple ECUs that communicate with each other and operate in cooperation.

[0019] Control unit 12 calculates a first torque command value based on the operation of driving operation unit 9 (accelerator operation amount and brake operation amount) and predetermined constraints. More specifically, control unit 12 first calculates a required torque corresponding to the accelerator operation amount or brake operation amount. The required torque means the torque required by the driving operation. Control unit 12 then calculates a target torque by adding several constraints, such as suppressing sudden torque fluctuations, to the required torque. The target torque is then set as the first torque command value for first drive source 4. Note that if there are multiple drive sources, control unit 12 determines the proportion of the target torque to be allocated to each drive source, and sets the target torque allocated to first drive source 4 as the first torque command value.

[0020] The first torque command value means the value of the torque output from the first driving source 4. The first torque command value is sent to a control circuit of the inverter 6, and the control circuit controls the operation of the inverter 6 by performing feedback control so that the first driving source 4 outputs a torque that matches the first torque command value. When the inverter 6 operates, power is sent between the battery 7 and the first driving source 4, the first driving source 4 operates in power running or regenerative mode, and the torque of the first torque command value is output.

[0021] Furthermore, when the predicted trajectory of the operating point of the first driving source 4 (see predicted trajectory K3 in FIG. 4 ) overlaps with the first resonance point X1, the control unit 12 decreases or increases the first torque command value so as to avoid the first resonance point X1. Here, the predicted trajectory of the operating point refers to the trajectory of the operating point when the torque change rate (change amount per unit time) is constant or the torque is constant. When calculating the trajectory of the operating point, the control unit 12 may calculate the amount of change in the rotational speed of the first driving source 4 from the torque and the inclination of the road surface. Alternatively, the amount of change in the rotational speed of the first driving source 4 may be calculated using the rate of change in the rotational speed relative to the immediately preceding torque instead of the inclination of the road surface. Each operating point on the predicted trajectory corresponds to a predicted destination of the operating point of the first driving source 4.

[0022] Furthermore, after the control unit 12 decreases or increases the first torque command value so as to avoid the first resonance point X1, if it determines that the predicted destination of the operating point of the first drive source 4 has avoided the first resonance point X1, it gradually increases or decreases the first torque command value to return it to the target torque. Then, when the first torque command value returns to the target torque, the control unit 12 again calculates the target torque as the first torque command. Increasing or decreasing means increasing or decreasing.

[0023] The operating point of the first drive source 4 is kept away from the first resonance point X1, thereby suppressing the generation of noise.

[0024] <Example of operation> Fig. 4 is a diagram illustrating an example of the operation of the vehicle control device according to the first embodiment. Trajectories J1 to J4 in Fig. 4 show the transition of the operating point A of the first driving source 4 in one example of driving of the vehicle 1. That is, Fig. 4 shows that the operating point A of the first driving source 4 transitions sequentially along the trajectories J1 to J5 in the operating region of the first driving source 4. In the example of driving in Fig. 4, the vehicle 1 accelerates due to the torque output of the first driving source 4, and the rotation speed of the first driving source 4 increases gradually accordingly.

[0025] In the locus J1, the driver increases the accelerator operation amount, which accordingly increases the torque of the first drive source 4. In the locus J2, the driver maintains the accelerator operation amount, which accordingly keeps the torque of the first drive source 4 approximately constant. When the operating point A is located in the operating region R3 where square wave control is performed, the control unit 12 determines whether the predicted destination of the operating point A, i.e., the operating point of the predicted locus K3, overlaps with the first resonance point X1.

[0026] In the driving example of FIG. 4, the driver maintains the accelerator operation amount while the operating point A transitions along the locus J3. Therefore, in the predicted locus K3, the torque remains constant and the rotation speed of the first drive source 4 increases, and the predicted locus K3 overlaps with the first resonance point X1. When the control unit 12 determines that the predicted locus K3 overlaps with the first resonance point X1, it decreases or increases the first torque command value so as to avoid the first resonance point X1. In the arrangement of the first resonance point X1 in FIG. 4, there is an area where the first resonance point X1 is avoided on the low torque side, so in this area the control unit 12 decreases the first torque command value. As a result, in the locus J3, the torque decreases, and the locus J3 avoids the first resonance point X1.

[0027] In the locus J4, the control unit 12 determines that the operating point of the first drive source 4 has avoided the first resonance point X1, and so gradually increases the first torque command value so that the operating point approaches the target torque, resulting in an increase in torque. After that, in the locus J5, the operating point A shifts according to the first torque command value that matches the target torque.

[0028] By this control operation, when the operating point of the first driving source 4 is about to overlap with the first resonance point X1 in the region where the first driving source 4 is square wave controlled, the torque of the first driving source 4 is decreased or increased to avoid the first resonance point X1. Therefore, noise caused by electrical vibrations around the battery 7, inverter 6, and first driving source 4 can be suppressed.

[0029] <Control processing> Next, an example of the control processing of the control unit that realizes the above control operation will be described. Fig. 5 is a flowchart showing the torque command value calculation processing executed by the control unit. When the vehicle 1 is in a state where it can travel, the control unit constantly and repeatedly executes the torque command value calculation processing of Fig. 5.

[0030] In the torque command value calculation process, the control unit 12 first receives a target torque calculated by another control process (step S1). The target torque is calculated based on the driving operation and predetermined constraints. Furthermore, the control unit 12 obtains a measured value of the rotational speed of the first drive source 4 from the speed sensor 4a (step S2).

[0031] Next, the control unit 12 branches the process based on the control state i (step S3), which is set to an initial value "0".

[0032] As a result, when the process proceeds to step S4 with the control state i=0, the control unit 12 outputs the target torque received in step S1 to the control circuit of the inverter 6 as a first torque command value (step S4).

[0033] Next, the control unit 12 calculates a predicted trajectory of the operating point A of the first driving source 4 using the first torque command value output at each control timing from the present time until a predetermined time ago and the value of the rotational speed of the first driving source 4 received at each control timing (step S5). The length (period length) of the calculated predicted trajectory is set to a period length that, when the predicted trajectory overlaps with the first resonance point X1, can avoid the first resonance point X1 by a subsequent torque change. The method of calculating the predicted trajectory can be the same as the method described above.

[0034] Next, the control unit 12 compares the predicted trajectory with the first resonance map M1 and determines whether the predicted trajectory overlaps with the first resonance point X1 (step S6). If the result is NO, the process returns to step S1, but if the result is YES, the control state i is changed to the value "1" for increasing or decreasing the first torque command value (step S7), and then the process returns to step S1.

[0035] If the control state i=1 as a result of the branching process in step S3, the control unit 12 branches the process to step S8. Then, the control unit 12 determines whether to decrease or increase the torque based on the arrangement of the multiple first resonance points X1 shown in the first resonance map M1 and the first torque command value output at the previous control timing (step S8). Here, the control unit 12 calculates the amount of torque change when the first resonance point X1 is avoided by decreasing the torque and the amount of torque change when the first resonance point X1 is avoided by increasing the torque, and selects the direction of torque (increase or decrease) that results in the smaller amount of change.

[0036] Next, the control unit 12 increases or decreases the first torque command value in the direction determined in step S8, and outputs the increased value to the control circuit of the inverter 6 (step S9). Here, the control unit 12 increases or decreases the first torque command value by increasing or decreasing the first torque command value output at the previous control timing by a predetermined amount. The increase or decrease in the first torque command value here may be independent of the transition of the target torque.

[0037] Next, the control unit 12 determines whether or not overlap of the operating point A with the first resonance point X1 has been avoided based on the output first torque command value and the arrangement of the multiple first resonance points X1 shown in the first resonance map M1 (step S10). Specifically, for example, the control unit 12 predicts the trajectory of the operating point A when the output first torque command value is gradually returned toward the target torque, and determines whether or not the trajectory overlaps with the first resonance point X1. If the result of the determination is YES, the control unit 12 can determine that overlap of the operating point A with the first resonance point X1 has not yet been avoided. If the result of the determination is YES, the control unit 12 returns the process to step S1. On the other hand, if the result is NO, the control unit 12 switches the control state i to a value "2" for returning the first torque command value toward the target torque (step S11), and then returns the process to step S1.

[0038] If the result of the branching process in step S3 is that the control state i=2, the control unit 12 branches the process to step S12. Then, the control unit 12 increases or decreases the first torque command value toward the target torque, and outputs it to the control circuit of the inverter 6 (step S12). Here, the control unit 12 simply adds or subtracts a predetermined amount of change to or from the first torque command value output at the previous control timing so that the first torque command value approaches the target torque.

[0039] Next, the control unit 12 determines whether the first torque command value output in step S12 is approximately equal to the target torque (whether the absolute value of the difference between the two is equal to or less than a threshold value) (step S13). If the result is NO, the control unit 12 returns the process to step S1. On the other hand, if the result is YES, the control unit 12 switches the control state i to the initial value "0" (step S14), and then returns the process to step S1.

[0040] According to the torque command value calculation process, the loop process (S1 to S6) for control state i=0 determines whether the predicted trajectory of the operating point overlaps with the first resonance point X1, and calculates the first torque command value when the trajectory does not overlap with the first resonance point X1. The loop process (S1 to S3, S8 to S10) for control state i=1 increases or decreases the first torque command value so that the trajectory of the operating point does not overlap with the first resonance point X1. The loop process (S1 to S3, S12 to S13) for control state i=2 returns the first torque command value to the target torque after avoiding the first resonance point X1.

[0041] In the torque command value calculation process, the control unit 12 may determine whether the operating point A of the first drive source 4 is located in the operating region R3 or the operating regions R2 and R3. Only when the result of the determination is YES, the control unit 12 may perform a process (S5) to calculate a predicted trajectory and a process (S6) to compare the predicted trajectory with the first resonance map M1. This control process reduces the load of the control process on the control unit 12 when the first drive source 4 is under sinusoidal wave control.

[0042] As described above, according to the vehicle control device 10 of the first embodiment, the storage unit 11 stores the first resonance map M1, in which one or more operating points at which resonance occurs in the operating region R3 of the first drive source 4 under square wave control are each indicated as a first resonance point X1. When the predicted destination of the operating point A of the first drive source 4 overlaps with the first resonance point X1, the control unit 12 decreases or increases the first torque command value so as to avoid the first resonance point X1. Therefore, even when the first drive source 4 is under square wave control, noise caused by electrical resonance occurring in the first drive source 4, the inverter 6, and their surroundings can be suppressed.

[0043] (Embodiment 2) 6 is a block diagram showing a vehicle equipped with a vehicle control device of embodiment 2. A vehicle 1A equipped with a vehicle control device 10 of embodiment 2 includes a second drive source 5 that outputs torque to a first wheel 2A in addition to the same configuration as in embodiment 1. Components similar to those in embodiment 1 are given the same reference numerals and descriptions thereof will be omitted.

[0044] The second drive source 5 is, for example, an internal combustion engine, and the vehicle 1A is equipped with an accessory 8 for driving the second drive source 5. The second drive source 5 may be an electric motor that is not rectangularly controlled. Furthermore, the first drive source 4 and the second drive source 5 may output torque to different wheels (the first wheel 2A and the second wheel 2B) instead of outputting torque to the same wheel (the first wheel 2A).

[0045] In addition to the first torque command value, the control unit 12 calculates a second torque command value indicating the value of the torque to be output by the second drive source 5. The second torque command value is output to a control circuit of the auxiliary device 8. The control circuit performs feedback control to operate the auxiliary device 8 so that the second drive source 5 outputs a torque that matches the second torque command value.

[0046] As in the first embodiment, the control unit 12 predicts the trajectory of the operating point A of the first driving source 4 so that the operating point of the first driving source 4 does not overlap with the first resonance point X1, and increases or decreases the first torque command value so as to avoid the first resonance point X1.

[0047] Furthermore, when the control unit 12 decreases the first torque command value so as to avoid the first resonance point X1, the control unit 12 performs processing to increase the second torque command value. Similarly, when the control unit 12 increases the first torque command value so as to avoid the first resonance point X1, the control unit 12 performs processing to decrease the second torque command value. This processing is performed when increasing or decreasing the first torque command value so as to reduce the amount of change in the total torque of the first driving source 4 and the second driving source 5, or so as to bring the total torque of the first driving source 4 and the second driving source 5 closer to the target torque for the entire vehicle 1A.

[0048] <Example of operation> 7A and 7B are diagrams illustrating an example of the operation of the vehicle control device according to embodiment 2. Fig. 7A shows the transition of operating point A of the first driving source 4 in one example of driving of the vehicle 1A. Fig. 7B shows the transition of operating point B of the second driving source 5 in the same example of driving as Fig. 7A. The timing at which the operating point of the first driving source 4 transitions along the locus J1 to J5 in Fig. 7A coincides with the timing at which the operating point of the second driving source 5 transitions along the locus J11 to J14 in Fig. 7B.

[0049] 7A and 7B, the vehicle speed gradually increases due to the torque output from the first driving source 4 and the second driving source 5, and accordingly the rotation speeds of the first driving source 4 and the second driving source 5 gradually increase. In this driving example, the driver maintains a constant accelerator operation amount while the operating point A transitions along the loci J3 and J4.

[0050] 7A, a trajectory J3 indicates the trajectory of the operating point A when the control unit 12 decreases the first torque command value to avoid the first resonance point X1, as in the first embodiment. A trajectory J4 indicates the trajectory of the operating point A when the control unit 12 increases the first torque command value to return the first torque command value to the target torque of the first drive source 4 after avoiding the first resonance point X1, as in the first embodiment.

[0051] In the second embodiment, as described above, when increasing or decreasing the first torque command value to avoid the first resonance point X1, the control unit 12 increases or decreases the second torque command value in the opposite direction to the first torque command value (trajectory J13 in FIG. 7B ). The opposite direction means a decrease direction relative to an increase direction, and an increase direction relative to a decrease direction. Similarly, when increasing or decreasing the first torque command value toward the target torque of the first drive source 4 after avoiding the first resonance point X1, the control unit 12 increases or decreases the second torque command value in the opposite direction (trajectory J14 in FIG. 7B ). By linking the second torque command value with the first torque command value and increasing or decreasing it in the opposite direction to the first torque command value in this way, it is possible to reduce fluctuations in the torque of the entire vehicle 1A when avoiding the first resonance point X1. Alternatively, it is possible to bring the torque of the entire vehicle 1A closer to the target torque of the entire vehicle 1A when avoiding the first resonance point X1.

[0052] <Control processing> Next, an example of the control processing of the control unit that realizes the above control operation will be described. Figures 8A and 8B are flowcharts showing the torque command value calculation processing executed by the control unit. Steps S1 to S14 in Figures 8A and 8B are the same as steps S1 to S14 (Figure 5) of the torque command value calculation processing in embodiment 1. Detailed description of the same steps will be omitted.

[0053] In the torque command value calculation process of the second embodiment, after step S2, the control unit 12 receives the target torque of the second driving source 5 calculated by another control process (step S21).

[0054] After step S4, the control unit 12 outputs the target torque received in step S21 to the control circuit of the auxiliary device 8 as a second torque command value (step S22).

[0055] After step S9, the control unit 12 increases or decreases the second torque command value in the direction opposite to the direction of increase or decrease of the first torque command value, and outputs the second torque command value to the control circuit of the auxiliary device 8 (step S23).

[0056] Furthermore, after step S12, the control unit 12 increases or decreases the second torque command value toward the target torque of the second drive source 5, and outputs the second torque command value to the control circuit of the auxiliary device 8 (step S24).

[0057] The above control process can realize a control operation in which the second torque command value increases or decreases in the opposite direction to the first torque command value in conjunction with an increase or decrease in the first torque command value when avoiding the first resonance point X1.

[0058] As described above, according to the vehicle control device 10 of the second embodiment, the control unit 12 increases the second torque command value when decreasing the first torque command value to avoid the first resonance point X1. Furthermore, the control unit 12 decreases the second torque command value when increasing the first torque command value to avoid the first resonance point X1. Therefore, when the first drive source 4 is subjected to square wave control to suppress noise caused by electrical resonance occurring in the first drive source 4, the inverter 6, and their peripheries, it is possible to reduce fluctuations in the torque of the entire vehicle 1A. Alternatively, it is possible to bring the torque of the entire vehicle 1A closer to the target torque of the entire vehicle 1A.

[0059] (Embodiment 3) Fig. 9 is a block diagram showing a vehicle equipped with a vehicle control device according to embodiment 3. Fig. 10 is a diagram showing a second resonance map stored in the storage unit.

[0060] A vehicle 1B equipped with a vehicle control device 10 of the third embodiment differs from the second embodiment mainly in that the second drive source 5 is an electric motor that is rectangularly controlled. A control unit 12 calculates a second torque command value that indicates the value of the torque to be output from the first wheel 2A in addition to a first torque command value. The second torque command value is output to a control circuit of an inverter 8A that drives the second drive source 5. The control circuit controls the operation of the inverter 8A by performing feedback control so that the second drive source 5 outputs a torque that matches the second torque command value. The vehicle 1B has a speed sensor 5a that directly or indirectly measures the rotational speed of the second drive source 5, and the measurement value of the speed sensor 5a is sent to the control unit 12.

[0061] The storage unit 11 of the vehicle control device 10 stores a second resonance map M2 in addition to the first resonance map M1 described in the first embodiment. As shown in Fig. 10 , the second resonance map M2 indicates, as second resonance points X2, one or more operating points at which resonance occurs in or around the second drive source 5 within an operating region R13 of the second drive source 5 when square wave control is performed. The second resonance map M2 is created in advance based on tests, simulations, or the like, and is stored in the storage unit 11.

[0062] The operating region of the second drive source 5 is represented by a two-dimensional region whose components are the rotational speed and torque of the second drive source 5, and one point in this region corresponds to one operating point of the second drive source 5. The operating region of the second drive source 5 includes an operating region R11 where sine wave control is performed, an operating region R13 where square wave control is performed, and an operating region R12 where transitional control between sine wave control and square wave control is performed.

[0063] The second resonance points X2 shown in the second resonance map M2 are included in the operating region R13 where square wave control is performed. The second resonance points X2 are typically concentrated in a specific rotational speed range W2 within the operating region R13. The specific rotational speed range W2 in which the second resonance points X2 are concentrated may be one or multiple. Furthermore, the second resonance points X2 are typically located on the high torque side of the specific rotational speed range W2, and are often not present on the low torque side.

[0064] In vehicle 1B, when both first driving source 4 and second driving source 5 output torque, the rotational speed of first driving source 4 and the rotational speed of second driving source 5 are constrained to a predetermined first ratio. For example, when the rotational motion of first driving source 4 is output to first wheel 2A at a reduction ratio of 1 / 4 and the rotational motion of second driving source 5 is output to first wheel 2A at a reduction ratio of 1 / 2, the rotational speed of first driving source 4 is the value obtained by multiplying the rotational speed of second driving source 5 by the first ratio of "2". The following describes the case where the first ratio is "1", i.e., the case where the rotational speed of first driving source 4 matches the rotational speed of second driving source 5, but the first ratio may be a value other than "1".

[0065] In the third embodiment, the operating point of the first drive source 4 is set so that it does not overlap with the first resonance point X1 and the operating point of the second drive source 5 is set so that it does not overlap with the second resonance point X2 at the same time. That is, the above setting is realized by making the resonant frequency characteristics of the first drive source 4 and its peripheral circuits different from the resonant frequency characteristics of the second drive source 5 and its peripheral circuits, or by making the gear ratio of the first drive source 4 different from the gear ratio of the second drive source 5. Alternatively, the above setting is realized by making both the resonant frequency characteristics and the gear ratio different.

[0066] As a result, the rotational speed range W1 (see Figure 2) in which the first resonance point X1 of the first resonance map M1 is located and the range obtained by multiplying the rotational speed range W2 (see Figure 10) in which the second resonance point X2 of the second resonance map M2 is located by the first ratio "1" do not overlap.

[0067] <Example of operation> 11A and 11B are diagrams illustrating an example of the operation of the vehicle control device according to embodiment 3. Fig. 11A shows the transition of operating point A of the first driving source 4 in one example of driving of vehicle 1B. Fig. 11B shows the transition of operating point B of the second driving source 5 in the same example of driving as Fig. 11A. The timing at which the operating point of the first driving source 4 transitions along the locus J31 to J37 in Fig. 11A coincides with the timing at which the operating point of the second driving source 5 transitions along the locus J41 to J47 in Fig. 11B.

[0068] 11A and 11B, the vehicle speed gradually increases due to the torque output from the first driving source 4 and the second driving source 5, and accordingly the rotation speeds of the first driving source 4 and the second driving source 5 gradually increase. In this driving example, the driver maintains a constant accelerator operation amount during the period when operating point A transitions along loci J32, J33, J35, and J36, and during the period when operating point B transitions along loci J42, J43, J45, and J46.

[0069] 11B, a locus J42 represents the locus of the operating point B when the control unit 12 reduces the second torque command value to avoid the second resonance point X2. A locus J43 represents the locus of the operating point B when the control unit 12 increases the second torque command value to return the second torque command value to the target torque of the second drive source 5 after avoiding the second resonance point X2.

[0070] 11A, loci J32 and J33 indicate the locus of operating point A when the control unit 12 increases or decreases the first torque command value in the direction opposite to that of the second torque command value when increasing or decreasing the second torque command value to avoid the second resonance point X2. By linking the first torque command value with the second torque command value and increasing or decreasing it in the direction opposite to that of the second torque command value in this way, it is possible to reduce fluctuations in the torque of the entire vehicle 1B when avoiding the second resonance point X2. Alternatively, it is possible to make the torque of the entire vehicle 1B approach the target torque of the entire vehicle 1B when avoiding the second resonance point X2.

[0071] 11A, a trajectory J35 represents the trajectory of the operating point A when the control unit 12 reduces the first torque command value to avoid the first resonance point X1. A trajectory J36 represents the trajectory of the operating point A when the control unit 12 increases the first torque command value to return the first torque command value to the target torque of the first drive source 4 after avoiding the first resonance point X1.

[0072] 11B, loci J45 and J46 indicate the locus of operating point B when the control unit 12 increases or decreases the second torque command value in the opposite direction to the first torque command value when increasing or decreasing the first torque command value to avoid the first resonance point X1. By linking the second torque command value with the first torque command value and increasing or decreasing it in the opposite direction to the first torque command value in this way, it is possible to reduce fluctuations in the torque of the entire vehicle 1B when avoiding the first resonance point X1. Alternatively, it is possible to make the torque of the entire vehicle 1B approach the target torque of the entire vehicle 1B when avoiding the first resonance point X1.

[0073] As described above, the rotation speed range W1 of the first drive source 4, in which the first resonance point X1 is located, and the rotation speed range W2 of the second drive source 5, in which the second resonance point X2 is located (the range obtained by multiplying this range by the first ratio "1"), do not overlap. Therefore, when the first torque command value is increased or decreased to avoid the first resonance point X1, there is no risk that the operating point B of the second drive source 5 will overlap the second resonance point X2 due to the linked increase or decrease in the second torque command value. Similarly, when the second torque command value is increased or decreased to avoid the second resonance point X2, there is no risk that the operating point A of the first drive source 4 will overlap the first resonance point X1 due to the linked increase or decrease in the first torque command value.

[0074] <Control processing>

[0075] Next, an example of the control processing of the control unit that realizes the above control operation will be described. Figures 12A and 12B are parts 1 and 3 of a flowchart showing the torque command value calculation processing executed by the control unit. Steps S1, S2, S4 to S7, S21, and S22 in Figure 12A are the same as steps S1, S2, S4 to S7, S21, and S22 (Figure 8A) of the torque command value calculation processing of embodiment 2. In addition, the processing when branching occurs in step S3 in Figure 12A when control state i = 1 or 2 is the same as the processing in Figure 8B. Detailed descriptions of the same steps will be omitted.

[0076] In the torque command value calculation process of the third embodiment, after step S21, the control unit 12 acquires the measured value of the rotation speed of the second driving source 5 from the speed sensor 5a (step S31).

[0077] In the branching process of step S3, in addition to the branches corresponding to the control states i=1 and 2, branches corresponding to the control states i=3 and 4 are added.

[0078] In the torque command value calculation process of the third embodiment, if step S6 in FIG. 12A returns NO, the control unit 12 calculates a predicted trajectory of operating point B of the second driving source 5 (step S32). The method for calculating the predicted trajectory is the same as the method for calculating the predicted trajectory of operating point A of the first driving source 4. Each operating point on the predicted trajectory corresponds to a predicted destination of operating point B. Next, the control unit 12 compares the predicted trajectory with the second resonance map M2 and determines whether the predicted trajectory overlaps with the second resonance point X2 (step S33). If the result is NO, the process returns to step S1. However, if the result is YES, the control state i is changed to a value of "3" to increase or decrease the second torque command value (step S34), and then the process returns to step S1.

[0079] As a result of the branching process in step S3, when the control state i=1 or 2, the same control process as in embodiment 2 is executed. That is, when the control state i=1, the processes in steps S8 to S10 and S23 in FIG. 8B are repeatedly executed, thereby decreasing or increasing the first torque command value so as to avoid the first resonance point X1. In addition, the second torque command value is increased or decreased in the direction opposite to the direction of increase or decrease of the first torque command value. Then, once the operating point A has avoided the first resonance point X1, the control state i is updated to "2" in step S11.

[0080] When the control state i=2, the processes of steps S12 to S13 and step S24 in FIG. 8B are repeatedly executed, thereby increasing or decreasing the first torque command value toward the target torque of the first driving source 4. In addition, the second torque command value is increased or decreased toward the target torque of the second driving source 5. Then, when the first torque command value substantially matches the target torque of the first driving source 4, the control state i is returned to "0" in step S14.

[0081] In the branching process of step S3, when the control state i=3, the control unit 12 proceeds to step S35 in FIG. 12B. Steps S35 to S39 are the same as the process sequence of steps S8, S9, S23, S10, and S11 in FIG. 8B. Steps S35 to S39 merely replace the first torque command value with the second torque command value, replace the first resonance point X1 with the second resonance point X2, and replace the control state i=2 with i=4 in the above process sequence. By repeatedly executing the processes of steps S35 to S38 in FIG. 12B, the second torque command value is decreased or increased so as to avoid the second resonance point X2. In addition, the first torque command value is increased or decreased in the direction opposite to the increase or decrease direction of the second torque command value. Then, when the operating point B has avoided the second resonance point X2, the control state i is updated to "4" in step S39.

[0082] In the branching process of step S3, when the control state i=4, the control unit 12 proceeds to step S40 in FIG. 12B. Steps S40 to S43 are the same as the process sequence of steps S12, S24, S13, and S14 in FIG. 8B. Steps S40 to S43 simply replace the first torque command value with the second torque command value and the target torque of the first driving source 4 with the target torque of the second driving source 5 in the above process sequence. By repeatedly executing the processes of steps S40 to S42 in FIG. 12B, the second torque command value is increased or decreased toward the target torque of the second driving source 5. In addition, the first torque command value is increased or decreased toward the target torque of the first driving source 4. Then, when the second torque command value approximately matches the target torque of the second driving source 5, the control state i is returned to "0" in step S43.

[0083] In the torque command value calculation process, the control unit 12 may determine whether the operating point A of the first driving source 4 is located in the operating region R3 or the operating regions R2 and R3. Then, only when the result of the determination is YES, the control unit 12 may perform a process (S5) to calculate a predicted trajectory of the operating point A and a process (S6) to compare the predicted trajectory with the first resonance map M1. The control unit 12 may also determine whether the operating point B of the second driving source 5 is located in the operating region R13 or the operating regions R12 and R13. Then, only when the result of the determination is YES, the control unit 12 may perform a process (S32) to calculate a predicted trajectory of the operating point B and a process (S33) to compare the predicted trajectory with the second resonance map M2. This control process reduces the load of the control process on the control unit 12 when the first driving source 4 is sinusoidally controlled and when the second driving source 5 is sinusoidally controlled.

[0084] By performing such torque command value calculation processing, the operations shown in FIGS. 11A and 11B are realized.

[0085] As described above, according to the vehicle control device 10 of the third embodiment, the control unit 12 increases the second torque command value when decreasing the first torque command value to avoid the first resonance point X1. Furthermore, the control unit 12 decreases the second torque command value when increasing the first torque command value to avoid the first resonance point X1. Therefore, when the first drive source 4 is subjected to square wave control to suppress noise caused by electrical resonance occurring in the first drive source 4, the inverter 6, and their peripheries, it is possible to reduce fluctuations in the torque of the entire vehicle 1A. Alternatively, it is possible to make the torque of the entire vehicle 1A closer to the target torque of the entire vehicle 1A. At this time, it is also possible to reduce the risk of noise caused by electrical resonance occurring in the second drive source 5, the inverter 8A, and their peripheries.

[0086] Similarly, when the control unit 12 decreases the second torque command value to avoid the second resonance point X2, it increases the first torque command value. Furthermore, when the control unit 12 increases the second torque command value to avoid the second resonance point X2, it decreases the first torque command value. Therefore, when the second drive source 5 is subjected to square wave control to suppress noise caused by electrical resonance occurring in the second drive source 5, the inverter 8A, and their peripheries, it is possible to reduce fluctuations in the torque of the entire vehicle 1A. Alternatively, it is possible to make the torque of the entire vehicle 1A approach the target torque of the entire vehicle 1A. At this time, it is also possible to reduce the risk of noise caused by electrical resonance occurring in the first drive source 4, the inverter 6, and their peripheries.

[0087] (Embodiment 4) FIG. 13 is a block diagram showing a vehicle control device according to a fourth embodiment. The vehicle control device 10 of the fourth embodiment can be mounted on the vehicle 1B of the third embodiment described above. In the fourth embodiment, a storage unit 11 of the vehicle control device 10 stores a plurality of first resonance maps M1 and a plurality of second resonance maps M2 corresponding to a plurality of environmental conditions, respectively. The environmental conditions include the outside air temperature, the temperatures of the first drive source 4 and the inverter 6, the temperatures of the second drive source 5 and the inverter 8A, and the output voltage of the battery 7. In addition, the environmental condition may be any condition that affects the position of the first resonance point X1 in the operating range of the first drive source 4 and the position of the second resonance point X2 in the operating range of the second drive source 5. The plurality of first resonance maps M1 and the plurality of second resonance maps M2 are stored in association with the plurality of environmental conditions, respectively.

[0088] The vehicle on which the vehicle control device 10 is installed has an environmental sensor 3 s that measures environmental conditions, and the measurement values ​​of the environmental sensor 3 s are output to the control unit 12 .

[0089] 14 is a flowchart showing the resonance map selection process executed by the control unit of embodiment 4. The control unit 12 executes the resonance map selection process when the system of the vehicle 1 is started up or when a change in the environment is expected. Then, the control unit 12 acquires a measurement value from the environment sensor 3s (step S51), and selects a first resonance map M1 and a second resonance map M2 corresponding to the measurement value (step S52).

[0090] Then, the control unit 12 executes the torque command value calculation process of the third embodiment using the selected first resonance map M1 and second resonance map M2.

[0091] In the vehicle control device 10 mounted on the vehicle 1, 1A shown in the first and second embodiments, a plurality of first resonance maps M1 corresponding to a plurality of environmental conditions may be stored in the storage unit 11. The vehicle 1, 1A shown in the first and second embodiments refers to a vehicle that does not have a second drive source 5 or a vehicle in which no resonance point exists in the operating range of the second drive source 5. In this case, the control unit 12 may select and use one first resonance map M1 corresponding to the environmental condition to calculate the first torque command value.

[0092] As described above, according to the vehicle control device 10 of the fourth embodiment, even when the resonance point changes depending on the environmental conditions, noise caused by electrical resonance occurring in the first drive source 4, the inverter 6, and their surroundings can be suppressed in response to the change. Similarly, noise caused by electrical resonance occurring in the second drive source 5, the inverter 8A, and their surroundings can be suppressed.

[0093] The program for the torque command value calculation process or the program for the resonance map selection process described above is stored in a non-transitory computer readable medium such as a ROM of the control unit 12. The control unit 12 may be configured to read and execute a program stored in a portable non-transitory recording medium. The portable non-transitory recording medium may store the program for the torque command value calculation process or the program for the resonance map selection process described above.

[0094] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. For example, in the above embodiments, the first resonance point is located close to the high torque end in the operating region under square wave control, and therefore the control unit reduces the first torque command value to avoid the first resonance point. However, the first resonance point may be located outside the high torque end. In such a case, the control unit may increase the first torque command value to avoid the first resonance point. The same applies to the second resonance point and the second torque command value. Furthermore, in the above embodiments, the control unit gradually increases or decreases the first torque command value to avoid the first resonance point. However, the same applies to the second torque command value. In addition, the details shown in the embodiments may be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0095] Cars 1, 1A, and 1B 2A 1st wheel 2B 2nd wheel 3s Environmental Sensor 4 First drive source 4a Speed ​​sensor 5 Second driving source 5a Speed ​​sensor 6, 8A inverter 7 Battery 8 Auxiliary Machinery 9 Driving operation section 10 Vehicle control device 11 Storage section 12 Control unit M1 First Resonance Map M2 Second Resonance Map X1 1st resonance point X2 2nd resonance point R3, R13 Square wave control operating area W1, W2 rotation speed range A, B operating point K3 Predicted trajectory

Claims

1. A vehicle control device mounted on a vehicle having a first drive source which is an electric motor and outputs torque to a first wheel, and a second drive source which is an electric motor and outputs torque to the first wheel or a second wheel different from the first wheel, a storage unit that stores a first resonance map and a second resonance map; a control unit that calculates a first torque command value indicating a value of torque to be output from the first drive source and a second torque command value indicating a value of torque to be output from the second drive source; Equipped with the first resonance map indicates, as first resonance points, one or more operating points at which resonance occurs in an operating region of the first drive source that is square wave controlled; the second resonance map indicates, as second resonance points, one or more operating points at which resonance occurs in an operating region of the second drive source that is controlled by rectangular waves; the control unit, when a predicted movement destination of the operating point of the first drive source coincides with the first resonance point, decreases or increases the first torque command value so as to avoid the first resonance point, and when decreasing the first torque command value so as to avoid the first resonance point, increases the second torque command value, and when increasing the first torque command value so as to avoid the first resonance point, decreases the second torque command value; components of the first resonance map include a rotation speed of the first drive source and a torque of the first drive source; components of the second resonance map include a rotation speed of the second drive source and a torque of the second drive source; the rotation speed of the first drive source is a value obtained by multiplying the rotation speed of the second drive source by a first ratio, A vehicle control device characterized in that the range of rotational speeds of the first drive source in which the first resonance point is located in the first resonance map does not overlap with the range obtained by multiplying the range of rotational speeds of the second drive source in which the second resonance point is located in the second resonance map by the first ratio.

2. The control unit When a predicted destination of the operating point of the second drive source coincides with the second resonance point, the second torque command value is decreased or increased so as to avoid the second resonance point, and 2. The vehicle control device according to claim 1, wherein the first torque command value is increased when the second torque command value is decreased so as to avoid the second resonance point, and the first torque command value is decreased when the second torque command value is increased so as to avoid the second resonance point.

3. the storage unit stores a plurality of the first resonance maps and a plurality of the second resonance maps corresponding to a plurality of environmental conditions, 3. The vehicle control device according to claim 1, wherein the control unit uses one of the first resonance maps and one of the second resonance maps corresponding to environmental conditions, from among the plurality of first resonance maps and the plurality of second resonance maps.

4. A vehicle control device as described in any one of claims 1 to 3, characterized in that when the control unit detects that the operating point of the first driving source will overlap with the first resonance point as the rotation speed of the first driving source increases, it changes the first torque command value in a first direction that is lower or higher than the target torque so as to avoid the first resonance point while increasing the rotation speed, and once the operating point of the first driving source has avoided the first resonance point, it changes the first torque command value in a direction opposite to the first direction to return it to the target torque.

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