Electronic control unit

Abstract

The present invention provides an electronic control device 110 that controls driving of a plurality of inductive loads and that is capable of prolonging the lifespan of an electronic component by minimizing the total amount of ripple current effective values of the electronic component. The electronic control device 110 comprises: a control unit 270 that, on the basis of driving state information of a plurality of inductive loads 130-150, sets driving output values that include the driving commencement timing, output duty ratio, and driving frequency of a plurality of load drivers 160-180 which drive the inductive loads 130-150; current output units 280, 300, 320 that output values of the currents flowing through the load drivers 160-180; and an ON timing setting unit 290 that, on the basis of the current values output by the current output unit 280, 300, 320, sets the timing of when to turn on the output of the driving output values in the load drivers 160-180. The ON timing setting unit 290 sets the ON timing of each of the load drivers 160-180 to a timing which offsets the ripple current effective value generated in an electronic component 120 connected via a power source line as a drive source of the plurality of inductive loads 130-150.

Description

[Technical Field]

[0001] The present invention relates to an electronic control device that drives an inductive load. [Background Art]

[0002] It is known that in a system configuration in which a plurality of inductive loads are controlled by a single control device, when the ON timings of outputs from the plurality of loads coincide with each other, heat generation increases due to ripple current, leading to a shortened service life of electronic components.

[0003] As a technique for extending the service life of electronic components, for example, as disclosed in Patent Document 1, a technique is known in which the ON timing of the output of a control device is shifted at fixed intervals to smooth the ripple current and suppress heat generation. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 9-331696 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] In the above-mentioned Patent Document 1, for a driver that is PWM (Pulse Width Modulation) controlled by a load control device, the ON timing of an output voltage is shifted for each driver, thereby smoothing the ripple current flowing through the electronic component and suppressing heat generation of the electronic component.

[0006] However, with the technique described in Patent Document 1, a ripple current corresponding to the current flowing through the load is generated in the electronic component at the timing when the load is turned ON / OFF. When the number of loads controlled by the driver or the load current increases, heat generation of the electronic component increases due to the increased ripple current, and the problem of shortened service life of the electronic component cannot be avoided.

[0007] Therefore, the object of the present invention is to provide a highly reliable electronic control device that drives and controls multiple inductive loads, by minimizing the total amount of the effective value of the ripple current of the electronic components constituting the electronic control device, thereby extending the lifespan of the electronic components. [Means for solving the problem]

[0008] To achieve the above objective, the present invention is configured as follows.

[0009] An electronic control device that generates control signals for controlling multiple inductive loads, comprising: a control unit that sets drive output values ​​including the start time of driving multiple load drivers that drive the multiple inductive loads, the output duty cycle and the driving frequency, based on various information relating to the driving state of the multiple inductive loads; and an output of the current value flowing through the multiple load drivers. do A current output unit, and based on the current value output by the current output unit, the drive output of the plurality of load drivers Force value The system includes an ON timing setting unit that sets the timing for turning on the output of the load drivers, and the ON timing setting unit ranks the load drivers in descending order of the current value flowing through them, and the output of the load driver with the third highest current value of Major I'll make it The timing is set as the reference value, and the output of the load driver is the one with the current value being the highest. of Major I'll make it The timing of the load driver in the third position Drive output of OFF I'll make it The timing is the output of the load driver when the current value is in the second position. of Major I'll make it The timing of the load driver in the first position Drive output of OFF I'll make it Each of the above-mentioned load drivers is set to the timing Output ON, OFF I'll make it Set the timing. Effects of the Invention

[0010] According to the present invention, in an electronic control device that drives and controls a plurality of inductive loads, a highly reliable electronic control device capable of suppressing heat generation caused by ripple current in electronic components constituting the electronic control device and a control method therefor can be realized.

[0011] Thereby, the service life of electronic components can be extended, and the extension of service life and reliability improvement of the electronic control device can be achieved.

[0012] Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments. Brief Description of the Drawings

[0013] [Figure 1] It is a diagram showing the basic configuration of the electronic control device according to Embodiment 1 of the present invention. [Figure 2] It is a diagram conceptually showing the operation of the electronic control device in Fig. 1. [Figure 3] It is a functional block diagram of the electronic control device in Fig. 1. [Figure 4] It is a flow chart showing the control method of the electronic control device according to Embodiment 1 of the present invention. [Figure 5] It is a timing chart showing the control method of the electronic control device according to Embodiment 1 of the present invention. [Figure 6] It is a timing chart showing the transient response time of ripple current cancellation according to Embodiment 1 of the present invention. [Figure 7] It is a functional block diagram of the electronic control device according to Embodiment 2 of the present invention. [Figure 8] It is a functional block diagram of the electronic control device according to Embodiment 3 of the present invention. [Figure 9] It is a functional block diagram of the electronic control device according to Embodiment 4 of the present invention. [Figure 10] It is a timing chart showing the control method of the electronic control device according to Embodiment 4 of the present invention. [Modes for carrying out the invention]

[0014] The embodiments of the present invention will be described below with reference to the drawings.

[0015] In addition, identical components are denoted by the same reference numerals in each drawing, and detailed explanations of overlapping parts are omitted. [Examples]

[0016] (Example 1) The electronic control device of Embodiment 1 of the present invention will be described with reference to Figures 1 to 6.

[0017] First, the basic configuration and operation of the electronic control device 110 to which the present invention is applied will be explained using Figures 1 and 2.

[0018] As shown in Figure 1, the electronic control device 110 to which the present invention is applied mainly comprises electronic components 120 such as electrolytic capacitors that suppress current fluctuations on the power supply line 100, load drivers 160, 170, and 180 for driving a plurality of external inductive loads 130, 140, and 150, and an integrated circuit device 190 such as a microcontroller for controlling the load drivers 160, 170, and 180.

[0019] The load drivers 160, 170, and 180 include one or all of the switching elements 200, 210, 220, and 230, such as MOS-FETs, for driving external inductive loads 130, 140, and 150, such as electric motors.

[0020] The integrated circuit device 190 includes a control unit 270 that performs various calculations necessary for the operation of the electronic control unit 110, as well as setting load drive information from the drive state of external inductive loads 130, 140, and 150 connected to the electronic control unit 110; a current detection unit 280 that detects the output current values ​​of the load drivers 160, 170, and 180; and an ON timing setting unit 290 that sets the timing for turning ON the output of the drive output values ​​of the load drivers 160, 170, and 180 based on the output current values ​​detected by the current detection unit 280.

[0021] The operation of the electronic control device 110 in Figure 1 will be explained using Figure 2.

[0022] The PWM waveform generated by the integrated circuit device 190 is input to the load drivers 160, 170, and 180. Based on the input PWM waveform, the switching elements in the load drivers 160, 170, and 180 start ON / OFF operation. By switching the ON / OFF state of the switching elements, the output voltages 240, 250, and 260 of the load drivers 160, 170, and 180 are changed to drive the external inductive loads 130, 140, and 150.

[0023] For example, when switching elements 200 and 230 are ON and switching elements 210 and 220 are OFF, current (a) flows from the power supply 100 to the external inductive load 130, causing the external inductive load 130 to rotate in the forward direction. Conversely, when switching elements 200 and 230 are OFF and switching elements 210 and 220 are ON, current (b) flows from the power supply 100 to the external inductive load 130, causing the external inductive load 130 to rotate in the reverse direction.

[0024] Next, using Figures 3 and 4, we will explain the functions of each part of the electronic control device 110 shown in Figure 1 and the control method performed by the electronic control device 110.

[0025] The control unit 270 within the integrated circuit device 190 sets the start timing of the load drivers 160, 170, and 180, as well as load drive information such as the PWM drive period and duty cycle, based on various states related to the driving of the external inductive loads 130, 140, and 150 connected to the electronic control unit 110.

[0026] The current detection unit 280 detects the output current flowing through the load drivers 160, 170, and 180. The method for detecting the output current is, for example, to acquire the peak value over a certain period while the external inductive loads 130, 140, and 150 are being driven.

[0027] Furthermore, the output current detection method of the present invention is not limited to obtaining peak values ​​over a certain period while the external inductive loads 130, 140, and 150 are driven. The same effects as the present invention can be obtained even when applied to an electronic control device 110 equipped with a similar program configuration for detecting the output current of load drivers 160, 170, and 180, such as obtaining the average value over a certain period.

[0028] The ON timing setting unit 290 uses the method shown in Figure 5, described later, to set ON timings that cancel out the ripple currents of the load drivers 160, 170, and 180 based on the load drive information set by the control unit 270, using the current detection unit 280's detected currents that are larger. The ON timing setting unit 290 corrects the load drive information of the control unit 270 based on the ON timing set for each load driver 160, 170, and 180.

[0029] The integrated circuit device 190 generates control signals to the load drivers 160, 170, and 180 based on the corrected load drive information.

[0030] Figure 3 is a functional block diagram of the electronic control unit 110. In Figure 3, the integrated circuit device 190 includes a waveform shaping unit 270W that generates a PWM waveform signal based on the drive output value from the control unit 270 and the setting value of the ON timing setting unit 290. The control unit 270 performs waveform shaping processing using the waveform shaping unit 270W and sets load drive information such as the drive start time, PWM drive period, and duty cycle of the load drivers 160, 170, and 180 based on various states related to the drive of the external inductive loads 130, 140, and 150 connected to the electronic control unit 110. The current detection unit 280 detects the output current flowing through the load drivers 160, 170, and 180. The ON timing setting unit 290 sets the ON timing to cancel out the ripple currents of the load drivers 160, 170, and 180 based on the load drive information set by the control unit 270, using the load drivers with larger detected currents from the current detection unit 280.

[0031] The control method described above is shown in the flowchart in Figure 4.

[0032] First, in step S100 of Figure 4, the control unit 270 acquires various states related to the driving of the external inductive loads 130, 140, and 150 connected to the electronic control unit 110.

[0033] Next, in step S110, the control unit 270 sets load drive information such as the start time of drive, PWM drive period, and duty cycle of the load drivers 160, 170, and 180, based on the various states acquired in step S100.

[0034] Next, in step S120, the current detection unit 280 detects the output current flowing through the load drivers 160, 170, and 180.

[0035] Subsequently, the process moves to step S130, where the ON timing setting unit 290 sets the ON timing to cancel out the ripple currents of the load drivers 160, 170, and 180 based on the load drive information set by the control unit 270, using the current detection unit 280's detected currents as a whole.

[0036] Next, in step S140, the ON timing setting unit 290 corrects the load drive information of the control unit 270 based on the ON timing set for each load driver 160, 170, and 180.

[0037] Finally, in step S150, the integrated circuit device 190 generates control signals to the load drivers 160, 170, and 180 based on the load drive information corrected by the control unit 270, and then terminates the process.

[0038] Using Figure 5 as an example, the method for setting the ON timing of load drivers 160, 170, and 180 based on the load drive information set by the control unit 270 and the current detected by the current detection unit 280 will be explained, with the case of three external inductive loads being used as an example. Figure 5 is an explanatory diagram of the control method of an electronic control device according to Embodiment 1 of the present invention.

[0039] The current detection unit 280 detects the output current flowing through the load drivers 160, 170, and 180, and then transmits the detected current to the ON timing setting unit 290. The ON timing setting unit 290 ranks the load drivers 160, 170, and 180 in descending order of their output current, as shown in the table in Figure 5.

[0040] Based on the ranking results, the ON timing setting unit 290 sets the ON timing of the load drivers 160, 170, and 180 so that it cancels out the effective value of the ripple current generated in the electrolytic capacitor 120 of electronic components connected by the power line as a drive source for the load.

[0041] For example, as shown in Figure 5, using the output voltage of the load driver 160 with an output current value of 3 as a reference, the ON timing of the output voltage of the load driver 180 with an output current value of 1 is set so that the ON / OFF timing of the output voltage of the load driver 160 with an output current value of 3 matches. Then, the ON timing of the output voltage of the output voltage of the 1st position is set so that the ON / OFF timing of the output voltage of the 1st position and the output voltage of the 2nd position match.

[0042] The ON timing of the output voltage set in circles 1 to 3 in Figure 5 can be expressed as follows.

[0043] (1) Set the output ON timing of the 3rd position (load driver 160) to 0 (reference value). (2) The output ON timing of position 1 (load driver 180) is set to ON Duty A of position 3 (load driver 160). (3) The ON timing of the 2nd position (load driver 170) output is equal to the ON Duty A of the 3rd position (load driver 160) + the ON Duty B of the 1st position (load driver 180).

[0044] The ripple current cancellation method of the present invention is not limited to (1) to (3) above, and may also be the relationship shown in Figure 6. In other words, as shown in Figure 6, in the relationship between a driver a and a driver b, the transient response times t1 and t2 of driver a to the rising or falling edge indication value of the output voltage and the transient response times t3 and t4 of driver b to the falling or rising edge indication value of the output voltage should overlap if the following conditions are met: t1-t3≧0 and t1-t4≦0 as shown in (A) and (C), or t2-t4≦0 and t2-t3≧0 as shown in (B). If such a relationship is met, the same effects as the present invention can be obtained even when applied to an electronic control device having a similar program configuration for canceling ripple current to the output voltage of load drivers 160, 170, and 180.

[0045] The difference between the example shown in (A) and the example shown in (C) lies in the relative magnitudes of the transient response times t2 and t4.

[0046] As described above, the electronic control device 110 of this embodiment 1 is configured to include a plurality of load drive circuits (load drivers 160, 170, 180), an integrated circuit device 190 that transmits control signals to the plurality of load drive circuits (load drivers 160, 170, 180), a control unit 270 that sets drive output values ​​including the drive start time, output duty cycle, and drive frequency of the load drive circuits (load drivers 160, 170, 180) based on various information regarding the drive state of the plurality of loads (130, 140, 150), a current detection unit 280 that detects the output current values ​​of the plurality of load drive circuits (load drivers 160, 170, 180), and an ON timing setting unit 290 that sets the timing for turning ON the output of the drive output values ​​in the plurality of load drive circuits (load drivers 160, 170, 180) based on the output current values ​​detected by the current detection unit.

[0047] The ON timing setting unit 290 then sets the ON timing of multiple load drive circuits (load drivers 160, 170, 180) so that the timing cancels out the effective values ​​of the ripple current generated in the electronic components 120 such as electrolytic capacitors, which are connected by power lines as driving sources for multiple loads (130, 140, 150).

[0048] According to the electronic control device 110 of this embodiment 1, by matching the ON / OFF timing of the output voltages 240, 250, and 260 of the load drivers 160, 170, and 180 according to the magnitude of the output current, the ripple current of electronic components 120 such as electrolytic capacitors can be canceled out, heat generation can be suppressed, and a highly reliable electronic control device can be realized. In this embodiment 1, the ON timing of each load driver 160, 170, and 180 can be set in descending order of their current values.

[0049] (Example 2) Next, with reference to Figure 7, the electronic control device 110 of Embodiment 2 of the present invention will be described.

[0050] Figure 7 is a functional block diagram of the electronic control device 110 of this embodiment 2, and corresponds to a modified example of embodiment 1 (Figure 3).

[0051] In Embodiment 1, as shown in Figure 3, the control unit 270 sets the start time of driving the load drivers 160, 170, and 180, as well as load driving information such as the PWM driving period and duty cycle, based on various states related to the driving of the external inductive loads 130, 140, and 150 connected to the electronic control unit 110. The current detection unit 280 then detects the output current flowing through the load drivers 160, 170, and 180. Furthermore, the ON timing setting unit 290 is configured to set an ON timing that cancels out the ripple currents of the load drivers 160, 170, and 180 based on the load driving information set by the control unit 270, using the load driving information of the load drivers 160, 170, and 180 with the largest detected currents from the current detection unit 280.

[0052] In contrast, the embodiment 2 shown in Figure 7 is an embodiment configured such that, instead of the current detection unit 280 detecting the output current flowing through the load drivers 160, 170, and 180, it includes a current estimation unit 300 that estimates the output current of the load drivers 160, 170, and 180 based on information such as the duty cycle and load constants of the external inductive loads 130, 140, and 150.

[0053] As shown in Figure 7, in the electronic control device 110 of this embodiment 2, the integrated circuit device 190 includes a current estimation unit 300 that estimates the output current of the load drivers 160, 170, and 180 from the duty cycle information of the external inductive loads 130, 140, and 150, and load constant information including inductance and resistance. The duty cycle information of the external inductive loads 130, 140, and 150, and load constant information including inductance and resistance are stored in a memory element such as the ROM 330 of the integrated circuit device 190.

[0054] The ON timing setting unit 290 sets the ON timing for the load drivers 160, 170, and 180 based on the output current estimated by the current estimation unit 300. The other configurations are the same as in Figure 3, and a detailed explanation is omitted.

[0055] As described above, in the electronic control device 110 of this embodiment 2, instead of the current detection unit 280 detecting the output current flowing through the load drivers 160, 170, and 180 as in embodiment 1, the current estimation unit 300 estimates the output current.

[0056] As a result, this embodiment 2 provides the same effects as embodiment 1, and also has the effect of reducing the processing load required for the integrated circuit device 190 and increasing the processing speed compared to embodiment 1.

[0057] (Example 3) Next, with reference to Figure 8, the electronic control device 110 of Embodiment 3 of the present invention will be described.

[0058] Figure 8 is a functional block diagram of the electronic control device 110 of this embodiment 3, and corresponds to a modified example of embodiment 1 (Figure 3).

[0059] In this embodiment 3 (Figure 8), when the ON timing setting unit 290 sets the ON timing for the load drivers 160, 170, and 180 based on the output current estimated by the current detection unit 280, it sets a threshold for the output current, and excludes drivers from the ON timing setting target if the current is below the set threshold. The other configurations are the same as in embodiment 1 (Figure 3) and embodiment 2 (Figure 7).

[0060] As shown in Figure 8, in the electronic control device 110 of this embodiment, the integrated circuit device 190 includes a current threshold determination unit 310 that determines whether the output current flowing through the load drivers 160, 170, and 180 exceeds a set threshold.

[0061] The setting threshold is determined, for example, from the information of the duty cycle and load constant of the external inductive loads 130, 140, and 150 as described in Example 2, and is stored in a memory element such as the ROM 330 of the integrated circuit device 190.

[0062] In Embodiment 3 shown in Figure 8, since the driver current of driver 1(160) is below the threshold, the current threshold comparison unit 310 excludes driver 1(160) from the ON timing setting target of the ON timing setting unit 290. The other configurations are the same as in Embodiment 1 shown in Figure 3, and a detailed explanation is omitted.

[0063] As described above, the electronic control device 110 of this embodiment 3 is configured to exclude load drivers 160, 170, and 180 whose output currents are below a set threshold from the ON timing setting target of the ON timing setting unit 290. This provides the same effects as in embodiment 1, and compared to embodiment 1, it reduces the processing load required for the integrated circuit device 190 and suppresses the impact on control caused by shifting the ON timing of the external inductive loads 130, 140, and 150.

[0064] (Example 4) Next, the electronic control device 110 of Embodiment 4 of the present invention will be described with reference to Figures 9 and 10. Figure 9 is a functional block diagram of the electronic control device 110 of Embodiment 4, and corresponds to a modified example of Embodiment 1 (Figure 3).

[0065] Figure 10 is a timing chart of the operation of this embodiment 4, as an example, when there are three external inductive loads.

[0066] As shown in Figure 9, in the electronic control device 110 of this embodiment 4, the ON timing setting unit 290 sets the ON timing to cancel out the ripple current, including combinations obtained by adding or subtracting the driver current detected by the current detection unit 280. The other configurations are the same as in Embodiment 1 (Figure 3), Embodiment 2 (Figure 7), and Embodiment 3 (Figure 8).

[0067] As shown in Figure 9, in the electronic control device 110 of this embodiment, the integrated circuit device 190 includes a current calculation unit 320 that adds or subtracts the output currents flowing through the load drivers 160, 170, and 180.

[0068] Figure 10 is a timing chart showing the control method of the electronic control device 110 according to Embodiment 4 of the present invention.

[0069] The example shown in Figure 10 is an example where the current detected by the current detection unit 280 is as follows: the detected current of load driver 160 is 0.8A, the detected current of load driver 170 is 0.5A, and the detected current of load driver 180 is 0.3A. The current calculation unit 320 then performs the following calculation: using the load driver 160 with the highest current value as the reference, it adds the current value of load driver 170 (0.5A) and the current value of load driver 180 (0.3A) to obtain 0.8A. Next, it subtracts the current value of the load driver 180 with the lowest current value (0.3A) from the current value of the load driver 170 with the highest current value (0.5A) to obtain 0.2A.

[0070] From the calculation results of the current calculation unit 320, the sum of the current value of load driver 170 (0.5A) and the current value of load driver 180 (0.3A) is 0.8A, which is the current value of load driver 160 (0.8A). Therefore, as shown in Figure 10, when the output voltage of load driver 160 falls, the output voltages of load driver 170 and load driver 180 can be raised, thereby completely canceling out the ripple current of load driver 160.

[0071] As shown in the example in Figure 10, if it is not possible to completely cancel out the ripple current of the load driver 160, the rising and falling edges of the output voltages of the load driver 160, load driver 170, and load driver 180 are set to suppress the ripple current based on the result of subtracting the current values ​​of the load drivers 170 and 180 (excluding the load driver 160 which has the highest current value).

[0072] As explained with reference to Figure 10, the ON timing setting unit 290 sets an ON timing combination that can cancel out the ripple current based on the results of the current calculation unit 320 adding and subtracting the output currents flowing through the load drivers 160, 170, and 180.

[0073] As described above, according to the electronic control device 110 of this embodiment 4, the ON timing setting unit 290 sets the ON timing of the load drivers 160, 170, and 180 based on the results of current addition and subtraction by the current calculation unit 320, thereby achieving a high ripple current cancellation effect even when using loads with large ripple currents.

[0074] The current detection unit 280 in Examples 1 and 3, and the current estimation unit 300 in Example 2, can be collectively referred to as current output units that output the current values ​​flowing through the load drivers 160, 170, and 180. Similarly, the current detection unit 280 and the current calculation unit 320 in Example 4 can also be collectively referred to as current output units that output the current values ​​flowing through the load drivers 160, 170, and 180.

[0075] Although Examples 1 to 4 describe an electronic control device 110, the present invention can be applied to any electronic control device having a similar circuit configuration for driving a load, such as in automotive, home appliance, or medical applications, and will yield the same effects as the present invention.

[0076] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are explained in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described.

[0077] Furthermore, it is possible to replace parts of the configuration of one embodiment with parts of the configuration of another embodiment, and it is also possible to add parts of the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with parts of other configurations. [Explanation of symbols]

[0078] 100...Power supply, 110...Electronic control unit, 120...Electronic component (electrolytic capacitor), 130...External inductive load 1, 140...External inductive load 2, 150...External inductive load n, 160...Driver 1, 170...Driver 2, 180...Driver n, 190...Integrated circuit device (microcontroller), 200...Switching element 1, 210...Switching element 2, 2 20... Switching element 3, 230... Switching element 4, 240... Driver output voltage 1, 250... Driver output voltage 2, 260... Driver output voltage n, 270... Control unit, 270W... Waveform generation unit, 280... Current detection unit, 290... ON timing setting unit, 300... Current estimation unit, 310... Current threshold determination unit, 320... Current calculation unit, 330... ROM

Claims

1. In an electronic control device that generates control signals for controlling multiple inductive loads, A control unit sets drive output values, including the drive start time, output duty cycle, and drive frequency, of a plurality of load drivers that drive the plurality of inductive loads, based on various information regarding the drive state of the plurality of inductive loads. A current output unit that outputs the current value flowing through the plurality of load drivers, An ON timing setting unit sets the timing for turning ON the output of the drive output value in the plurality of load drivers based on the current value output by the current output unit, Equipped with, The ON timing setting unit ranks the multiple load drivers in descending order of the current values ​​flowing through them, sets the timing for turning ON the output of the load driver with the third-highest current value as the reference value, sets the timing for turning ON the output of the load driver with the highest current value as the timing for turning OFF the drive output of the third-highest load driver as the timing for turning ON the output of the load driver with the second-highest current value as the timing for turning OFF the drive output of the first-highest load driver as the timing for turning ON the output of the load driver with the second-highest current value as the timing for turning OFF the drive output of the first-highest load driver as the reference value, and sets the timing for turning ON and OFF the output of each of the multiple load drivers.

2. In the electronic control device according to claim 1, The current output unit is a current estimation unit that estimates the output current of a plurality of load drivers based on information of the output duty cycle and load constant of each of the plurality of inductive loads, and the ON timing setting unit sets the timing for turning ON the output of the drive output value based on the estimation result of the current estimation unit.

3. In the electronic control device according to claim 1, The inductive load is an electric motor, and the electronic control device is characterized by comprising a waveform generation unit that generates a PWM waveform signal based on the drive output value and the setting value of the ON timing setting unit.

4. In the electronic control device according to claim 1, The system includes a current threshold determination unit that compares the current value flowing through each of the multiple load drivers that drive the multiple inductive loads with a predetermined threshold, An electronic control device characterized in that the load driver, which is determined by the current threshold determination unit to be carrying a current below a predetermined threshold, is excluded from the ON timing setting target in the ON timing setting unit.

Images