LOAD CONTROL SWITCH AND LOAD CONTROL SYSTEM

Abstract

Load control circuit, which includes the following: a switching element (70) that controls a load (a fuel injector (100)); and a diagnostic unit which, based on a control command of the switch element (70) and a signal at an output terminal of the switch element (70), diagnoses a deviation in the response behavior of the switch element (70). an excitation identification signal generation unit that compares a voltage at the output terminal of the switching element (70) and a predetermined voltage threshold to distinguish whether the switching element (70) is in an excitation state or an open state or not, and outputs an excitation identification signal (81) that represents the discrimination result, wherein the diagnostic unit uses the excitation identification signal (81) to diagnose a delay time between the control command and the excitation identification signal (81) and / or an excitation time of the switching element (70) and / or the number of repetitions of the excitation of the switching element (70).

Description

Technical field

[0001] The present invention relates to a load control circuit that controls an electrical load. Background area

[0002] In a fuel injection control device for an internal combustion engine, a control device (load control circuit) contains a switch for controlling the excitation of a fuel injector and actuates the switch according to a fuel injection command calculated by the microcomputer, thereby controlling the excitation of the fuel injector. The fuel injector is opened as a result of this excitation, causing it to inject fuel.

[0003] In recent years, as a countermeasure to improve the exhaust performance of internal combustion engines, multi-stage fuel injection control has been used, in which the fuel is injected at least several times during a combustion cycle. With multi-stage fuel injection control, the fuel injector opens multiple times during a combustion cycle. In this case, compared to conventional fuel injection, greater accuracy in the injection timing or injection quantity was required. Therefore, the fuel injection control device is necessary to monitor whether the control device responds correctly to each fuel injection command.

[0004] The following PTL 1 discloses a fuel injection control device in which an electronic control unit, which calculates a fuel injection quantity, and a actuator, which actuates a fuel injector, are provided separately. In PTL 1, the electronic control unit excites the fuel injector in response to a fuel control signal based on a fuel injection command calculated by the electronic control unit. The fuel injection control device detects an actuation current for the actuator to excite the fuel injector and outputs the detection signal to the electronic control unit.The electronic control unit compares the fuel injection command or the injection control signal based on the fuel injection command with the detection signal and determines, based on the comparison result, whether a control circuit correctly outputs a control signal to the fuel injector that corresponds to the fuel injection command.

[0005] US 2016 / 0160783A1 discloses a device for controlling fuel injectors in which a drive circuit supplies current individually to the coils of several injectors. The current flowing through a common path for all coils is monitored by a current sensing element. A power-on protection element forcibly terminates the current flow to the coil when the measured power-on duration reaches a predetermined threshold, based on the signal supplied by the current sensing element. During a non-injection operating phase, a diagnostic element checks whether the protection element is functioning correctly. For this purpose, current is briefly applied to a coil so that the associated valve does not open, and the test is performed sequentially for all coils.

[0006] US Patent 2018 / 0010545A1 discloses a device for monitoring a multi-point injection control system, which determines whether the system is operating normally or faulty and initiates a fault correction measure if necessary. The invention includes, among other things, fuel injectors, each assigned to a cylinder, and a means for detecting the open and / or closed state of these injectors based on the control currents or voltages. A further means determines the period for performing the state monitoring, including the start and end of the detection.

[0007] US Patent 2009 / 0184576A1 discloses a control system for an internal combustion engine that controls an electromagnetic load, such as a fuel injector, and enables diagnostics of the regenerative braking circuit. For this purpose, the potential at the diagnostic position is controlled via a current or voltage source. The diagnosis is performed based on the input or output voltage or regenerative braking current of a switching element, whereby the diagnostic point in time is defined or multiple measurements are averaged. List of prior art patent literature

[0008] PTL 1: JP 2013 - 36 344 A Summary of the invention: Technical problem

[0009] The invention described in PTL 1 consists of checking whether an output current for controlling the fuel injector of the control circuit is normal or not, and does not consist of monitoring an operation of the fuel injector itself or a valve opening time. Furthermore, a current detection resistor is inserted in series in an output stage of the control device to detect the output current of the control device. Therefore, the output impedance is high, and the energy loss is high compared to a case where the current detection resistor is not provided. Since the output current detection signal is required for each fuel injector to be controlled, the electronic control unit and the control device each require the same number of input / output connections as the fuel injector.Therefore, additional costs are required to provide a new input / output connection.

[0010] The present invention was made with regard to the above problems; one object of the present invention is to monitor the response behavior between the electronic control unit and the load control circuit with a simple configuration, without degrading the properties of the load control circuit. Solution to the problem

[0011] The problem is solved by the features of the independent claims. Advantageous embodiments of the invention are described in the dependent claims. A load control circuit according to the present invention diagnoses a deviation in the response behavior of a switch element that controls a load, based on a control command of the switch element and a signal at an output terminal of the switch element. Advantageous effects of the invention

[0012] According to the load control circuit of the present invention, the response behavior of the output of the load control circuit with respect to the fuel injection command calculated by the electronic control unit can be diagnosed with a simple configuration. Therefore, it is possible to adequately monitor the operation of a fuel injection control device that leads to a deviation in the fuel injection timing or the actual fuel injection time, even in multi-stage injection control, which requires higher accuracy than in related fields. Other problems, configurations, and advantageous effects relating to the present invention, beyond those described above, are explicitly shown in the descriptions of the following embodiments. Brief description of the drawings Fig. Figure 1 is a configuration diagram of a load control system 1 according to a first embodiment. Fig. Figure 2 illustrates a waveform of an output 72 of a control device 20 when a switch element 70 is controlled to be switched on and off. Fig. Figure 3 is a time diagram that explains a change over time of a signal value, which represents a result determined by the signal measurement / comparison determination circuit 90. Fig. Figure 4 is a time diagram that explains a relationship between a mass fault and an excitation identification. Fig. Figure 5 is a configuration diagram of a load control system 1 according to a second embodiment. Fig. Figure 6 illustrates a waveform of an output 72 of a control device 20 when a switch element 70 is controlled such that it is turned on and off. Fig. Figure 7 is a time diagram that explains a relationship between a mass fault and an excitation identification. Fig. Figure 8 is another example of a time diagram that explains a change over time of a signal value, which represents a result determined by the signal measurement / comparison determination circuit 90. Description of the embodiments<Erste Ausführungsform>

[0013] Fig. Figure 1 is a configuration diagram of a load control system 1 according to a first embodiment of the present invention.

[0014] The load control system 1 is a system that actuates and controls a fuel injector 100, which injects fuel into an internal combustion engine. The load control system 1 includes an electronic control unit (ECU) 10 and a control device (load control circuit) 20.

[0015] The control device 20 is a device that actuates and controls an electrical load (fuel injector 100) by supplying a control current to the electrical load. The output 72 of the control device 20 is connected to the fuel injector 100, and the fuel injector 100 is controlled such that it opens and closes according to the current of output 72.

[0016] The electronic control unit 10 stores a fuel injection control program in memory (not illustrated). A central processing unit (CPU) 30 executes the program to calculate a combustion injection quantity and its timing based on an operating state or situation of the internal combustion engine. The CPU 30 generates an injection command 31 for each fuel injector 100 and outputs the generated injection command 31 from an I / O port 40 to the actuator 20. The injection command 31 can be output to the actuator 20 via a communication interface 50, which exchanges setting or status information between the electronic control unit 10 and the actuator 20.

[0017] An input signal determination circuit 60 receives the injection command 31 from the electronic control unit 10 and encodes the received injection command 31, for example, into an injection control signal 61 with a high level during injection and a low level during the interruption. A gate input 71 of a switching element 70 is controlled such that the switching element 70 (e.g., a metal oxide semiconductor field-effect transistor (MOSFET)) is switched on when the injection control signal 61 has a high level, and the switching element 70 is switched off when the injection control signal 61 has a low level, such that the gate control circuit 65 controls the excitation and interruption of the fuel injection valve 100.

[0018] A comparator 80 compares a voltage level of output 72 with a predetermined excitation determination threshold voltage 86 and determines that the switching element 70 is switched on (energized) when the voltage level is lower than the excitation determination threshold voltage 86, and that the switching element 70 is switched off (open) when the voltage level is greater than or equal to the excitation determination threshold voltage 86, thereby identifying an operating state of the control device 20. Waveform examples of the voltage level and a current level of output 72 are described below. The comparator 80 outputs the determination result as an excitation identification signal 81. The excitation identification signal 81 is, for example,A signal indicating a high level when it is determined that switch element 70 is turned on (energized), and a signal indicating a low level when it is determined that switch element 70 is turned off (open). Although in . Fig. Not illustrated in Figure 1, filter processing can be performed to remove interference and the like from the excitation identification signal 81.

[0019] An excitation determination threshold voltage 86 can be easily generated by the control device 20 and can be set to a suitable voltage level so that no incorrect determination is made between a lower limit of the voltage level of the output 72 when the switching element 70 is off and an upper limit of the voltage level of the output 72 when the switching element 70 is on.

[0020] The excitation identification signal 81, together with the injection control signal 61, is input into a signal measurement / comparison circuit 90. Based on the input signal, the signal measurement / comparison circuit 90 determines whether the switch element 70 is actuated normally (i.e., whether no abnormal excitation has occurred) or not, and outputs the result to the electronic control unit 10 via the communication interface 50.

[0021] Fig. Figure 2 illustrates a waveform of the output 72 of the control device 20 when the switching element 70 is controlled to be switched on and off. When the switching element 70 is off, the output 72 to the fuel injector 100 has a voltage level close to the voltage level of a DC power supply 200 (a battery and the like, or an amplified voltage thereof) connected to one side of an upper electrode of the fuel injector 100. When the switching element 70 is controlled to be switched on, the output 72 has a voltage level close to the voltage level of ground, and the excitation of the fuel injector 100 begins.Since the fuel injector 100 has an inductive load, the current flowing through output 72 gradually increases, and thus the voltage level of output 72 also increases due to the ON resistance of the switch element 70. Because the ON resistance of the switch element 70 is typically 0.5 ohms or less, even when a current flows that is necessary to open the fuel injector 100, such as a current with a level of 1 A, the voltage level of output 72 rises in the range of a few hundred mV or less.

[0022] When the switch element 70 is controlled from an on state to an off state, a high surge voltage is generated due to an electromotive force caused by the inductive load of the fuel injector 100. This surge voltage is clamped by an active clamping circuit 75 between the gate input 71 and the output 72 of the switch element 70 at a voltage that does not exceed the device standby voltage of the switch element 70. This clamping voltage causes the voltage at the gate input 71 to rise. As a result, the switch element 70 remains in the on state for a period of time, and therefore the voltage level of the output 72 is reduced from the level clamped by the active clamping circuit 75 to a level close to the voltage level of the DC power supply 200.

[0023] Fig. Figure 3 is a timing diagram that explains the temporal change of a signal value, which represents a result determined by the signal measurement / comparison circuit 90. The signal measurement / comparison circuit 90 determines the following: (a) a response delay time between the injection control signal and the excitation identification signal 81, (b) a difference (or ratio) between an injection control time and an excitation time, and (c) a difference between the number of injection control repetitions and the number of excitation repetitions. The operation of the signal measurement / comparison circuit 90 is described below with reference to Fig. 3 described.

[0024] The electronic control unit 10 transmits a measurement start trigger 56 as a measurement start instruction to the control device 20 via the communication interface 50. With the measurement start instruction as a trigger, the electronic control unit 10 and the control device 20 initialize a measurement function to begin the measurement.

[0025] An injection control signal 51 and the excitation identification signal 81, which are received by the control device 20, are not necessarily synchronized with a communication frame of the communication interface 50.

[0026] The measurement function is initialized in synchronization with an output rise of the injection control signal 61 (transitioning from a low level to a high level) after the measurement start trigger 56 has been entered, thus initiating the measurement. The measurement start trigger 56 is not necessarily entered. For example, the measurement is started at the point in time when the injection control signal 61 first rises after the control device 20 has been activated, and automatic initialization and automatic start of the measurement can be performed each time the measurement result is transmitted to the electronic control unit 10 via the communication interface 50. The measurement start trigger 56 can be set individually for each measurement object.

[0027] When measuring a time, such as the response delay time described below, a cycle of a working clock used in the control device 20 can be used as a reference. For example, a timing circuit can be used that multiplies the required time accuracy by a constant and uses the result as the minimum resolution. As the maximum measurement time for each object under test, after ensuring a possible time range during the general use of the timing circuit, a value can be measured that can be used to determine a deviation.

[0028] The response delay time is the time from the rise of the injection control signal 61 until the rise of the excitation identification signal 81, which is a response to the injection control signal 61. The signal measurement / comparison determination circuit 90 compares the measured response delay time with a threshold for permissible delay (time window). The threshold for permissible delay can be set, for example, based on the worst value of the variation in the propagation delay from the injection control signal 61 to the excitation identification signal 81 inside and outside the control device 20. If the response delay time is greater than or equal to the threshold for permissible delay, it is determined that the response delay is abnormal. When the deviation of the response delay is detected, an identification marker for it is stored in a register.The register holds the identification mark until the information has been transmitted to the electronic control unit 10 via the communication interface 50.

[0029] The injection timing is the time from the rise to the fall of the injection control signal 61 (transition from a low level to a high level). The excitation time is the time from the rise to the fall of the excitation identification signal 81. When the injection control signal 51 and the excitation identification signal 81, which transition from a low level to a high level and then back to a low level, are set to a pulse, the signal measurement / comparison determination circuit 90 performs the measurement for each pulse. Because a pulse of the excitation identification signal 81, which is a response to a pulse of the injection control signal 61, has a response delay, the measurement result for the injection timing of the injection control signal 51 is held in the register until the measurement of the excitation time of the excitation identification signal 81, which is the response, is complete.The signal measurement / comparison determination circuit 90 compares and determines the injection timing and the excitation time at a time when the measurement result of the excitation time is obtained.

[0030] If the rise of the excitation identification signal 81 does not appear due to a deviation of the control device 20, even if the threshold for a permissible response delay is exceeded, it is assumed that excitation does not occur, and the excitation time can be set to "0" at a point when the injection timing measurement is complete. If the fall of the excitation identification signal 81 does not appear due to the output 72 of the control device 20 being fixed to a ground level or the like, the excitation time measurement on the corresponding pulse of the excitation identification signal 81 is complete at a point when the maximum measurement time is reached, and the excitation time can be set to the maximum measurement time.

[0031] The signal measurement / comparison circuit 90 calculates an absolute value error, an accuracy error of a ratio, or the like, based on permissible criteria for determining the error between the injection timing and the excitation time. The signal measurement / comparison circuit 90 determines an excitation time deviation for each pulse of the injection control signal using a permissible error amount as a threshold. If an error exceeding the permissible error amount is detected, a marker indicating that the error has been detected is stored in the register. The register retains the marker until the information has been transmitted to the electronic control unit 10 via the communication interface 50.

[0032] The number of injection control repetitions is the number of rises in the injection control signal 61. The number of excitation repetitions is the number of rises in the excitation identification signal 81. Generally, the number of injection control repetitions and the number of excitation repetitions are the same. However, the rise in the excitation identification signal 81, which is a response to the rise in the injection control signal 61, has a response delay. Therefore, the signal measurement / comparison circuit 90 waits for the rise in the excitation identification signal 81 and compares the number of injection control repetitions with the number of excitation repetitions. If a fault is detected that exceeds the permissible fault amount, a flag indicating that the fault has been detected is stored in the register.The register holds the license plate until the information has been transmitted to the electronic control unit 10 via the communication interface 50.

[0033] If the rise in the excitation identification signal 81 does not appear due to a deviation in the control device, even when the threshold for a permissible response delay is exceeded, a comparative measurement can be performed at the time the threshold for a permissible delay is reached. The comparative determination result is not limited to the presence or absence of the error between the number of injection control repetitions and the number of excitation repetitions. For example, the comparative determination result can be represented by a difference value between the number of injection control repetitions and the number of excitation repetitions.The maximum count value of the number of injection control repetitions can be determined based on an access frequency (one cycle) to the measured result via communication interface 50, the number of injection repetitions to be estimated between accesses, or the like.

[0034] The signal measurement / comparison circuit 90 transmits the response delay time, the injection control time, the excitation time, the number of injection control repetitions, and the number of excitation repetitions as shown in Fig. Figure 3 illustrates a comparison determination result transmitted via the communication interface 50 to the electronic control unit 10. The electronic control unit 10 can diagnose the deviation of the control device 20, which leads to an error in the fuel injection quantity or injection timing, using the comparison determination result 91. The electronic control unit 10 performs processing, such as issuing an engine warning, depending on the presence or absence of a deviation and its content.

[0035] Fig. Figure 4 is a timing diagram illustrating the relationship between a ground fault and excitation identification. When the fuel injector 100 has a ground fault, the voltage level of output 72 decreases, allowing the voltage level to be compared to the threshold, thus detecting the occurrence of the ground fault. The ground detection threshold can be the same as the excitation determination threshold of the switch element 70. Therefore, the signal measurement / comparison circuit 90 can compare the excitation identification signal 81 with the excitation determination threshold, thereby determining the excitation state of the switch element 70 and detecting the occurrence of the ground fault. However, the signal measurement / comparison circuit 90 determines the occurrence of a ground fault during a period when the injection control signal 61 indicates that the switch element 70 is open.Therefore, the signal measurement / comparison determination circuit 90 can perform the determination of the excitation state of the switch element 70 and the determination of the ground fault separately.

[0036] If it is determined that the ground fault occurs during a period in which the injection control signal 61 indicates that the switch element 70 is open, an unintended excitation occurs. The signal measurement / comparison circuit 90 identifies such an excitation as a deviation. In an example from Fig. 4. The third and fourth excitations are considered as deviating excitations. The signal measurement / comparison determination circuit 90 measures the third and fourth excitation times as a deviating excitation time. In an example from Fig. 4. Due to the ground fault, the excitation is continuously determined even after the initial excitation is complete. Therefore, the entire initial excitation period is considered as a deviation by the signal measurement / comparison circuit 90. <Erste Ausführungsform: Zusammenfassung>

[0037] In the load control system 1 according to the first embodiment, the control device 20 determines the excitation state of the switching element 70 using the output voltage of the switching element 70 and transmits the result to the electronic control unit 10. Since the determination is made using the output voltage of the switching element 70, a detection resistor for detecting the output current or the like is not necessarily required on the fuel injector 100. Therefore, a new input connection is not necessarily required in the control device 20 and the electronic control unit 10. Consequently, a fuel injection timing target or the fuel injection time can be appropriately monitored with a simple configuration.

[0038] Since the control device 20 in the load control system 1, according to the first embodiment, determines the excitation state of the switching element 70, it is not necessary to transmit, for example, the excitation identification signal 81 to the electronic control unit 10 in real time. Therefore, it is not necessary to provide a high-speed communication channel between the electronic control unit 10 and the control device 20, and thus the existing communication interface 50 can be used. Therefore, a fuel injection timing target or the fuel injection time can be monitored appropriately with a simple configuration.

[0039] In the load control system 1 according to the first embodiment, the excitation identification signal 81, which is output by the comparator 80, can be used jointly for both ground fault detection and excitation identification. Therefore, for example, if the control device 20 already has a circuit configuration for detecting the ground fault, this circuit configuration can be used to identify the excitation state of the switching element 70. That is to say, there is an advantage in that the object of the present invention can be solved without significantly altering the design of the control device 20. <Zweite Ausführungsform>

[0040] Fig. Figure 5 is a configuration diagram of a load control system 1 according to a second embodiment of the present invention.

[0041] The load control system 1 according to the second embodiment includes a comparator 85 in addition to the configuration described in the first embodiment. The comparator 85 compares a voltage level of an output 72 with a second threshold voltage 88, which is described below. An excitation identification signal 81 is calculated by performing a logical AND operation on the output of the comparator 80 and the negation of the output of the comparator 85. The determination criteria of the signal measurement / comparison determination circuit 90 are described below.

[0042] Fig. Figure 6 illustrates a waveform of the output 72 of the control device 20 when the switching element 70 is controlled to turn on and off. When the comparator 80 controls the switching element 70 to turn on, the output 72 gradually increases due to a current flowing through the output 72, after the output 72 has transitioned to a voltage level close to that of ground. The rising voltage level is detected, thus identifying the turning on (excitation) and turning off (breaking) of the switching element 70.

[0043] The comparator 80 determines whether the switching element 70 is turned on or off by comparing the voltage level of the output 72 with a first threshold voltage 87. A comparator 85 determines whether current flows to the switching element 70 or not by comparing the voltage level of the output 72 with the second threshold voltage 88. If the voltage level of the output 72 is lower than the first threshold voltage 87 and higher than the second threshold voltage 88, the signal measurement / comparison circuit 90 determines that the switching element 70 is turned on (energized). If the voltage level of the output 72 is greater than or equal to the first threshold voltage 87 and less than or equal to the second threshold voltage 88, the signal measurement / comparison circuit 90 determines that the switching element 70 is turned off (open). The first threshold voltage 87 can be the same voltage level as the excitation threshold voltage 86. Fig. exhibit 1. As in Fig. As illustrated in Figure 6, the second threshold voltage 88 is set to a suitable voltage level so that there is no slight fluctuation in the determination and no incorrect determination is made between an upper limit of the voltage level when the switching element 70 is switched on and a ground level.

[0044] According to a procedure for identifying an excitation as in Fig. As illustrated in Figure 6, the output 72 cycles through a value ranging from the first threshold voltage 87 to the second threshold voltage 88 when the switching element 70 is controlled such that it is switched on (excited). That is, during the transition from the off (interruption) state to the switch-on (excitation) state, a period occurs in which the switch-on (excitation) state is determined (section in Figure 6). Fig. 6, which is surrounded by a dotted circle). The instantaneous excitation identification signal 81 can be removed by a noise removal filter or the like, or the same processing can be performed by ignoring the instantaneous turn-on determination by the signal measurement / comparison determination circuit 90. For example, the signal measurement / comparison determination circuit 90 can include a filter.

[0045] Fig. Figure 7 is a timing diagram that explains the relationship between a ground fault and excitation identification. When the wiring between the fuel injector 100 and the control device 20 is disconnected, the voltage level of output 72 drops, and thus the voltage level can be compared to the threshold, thereby detecting the occurrence of the disconnection. The disconnection detection threshold can be the same as the excitation determination threshold of the switching element 70. That is, if the voltage level of output 72 is lower than the first threshold voltage 87 and higher than the second threshold voltage 88, the signal measurement / comparison determination circuit 90 determines that a disconnection has occurred. However, the signal measurement / comparison determination circuit 90 determines the occurrence of the disconnection during a period in which the injection control signal 61 instructs the switching element 70 to energize.Therefore, the signal measurement / comparison determination circuit 90 can perform the determination of the excitation state of the switch element 70 and the determination of the separation separately.

[0046] If it is determined that the separation occurs during a period in which the injection control signal 61 indicates that the switch element 70 is energized, the excitation identification signal 81 transitions to an off state earlier than an injection control period during the excitation period. The signal measurement / comparison determination circuit 90 identifies such an excitation as a deviation from the original excitation if the excitation identification signal 81 transitions in this manner. In an example from Fig. 7. The second to fourth excitations are considered as deviating excitations. The signal measurement / comparison determination circuit 90 measures the second to fourth excitation times as a deviating excitation time. Furthermore, in an example from Fig. 7. The excitation time is set to 0 because the separation occurs over the entire first injection control period. Therefore, the entire first excitation period is considered as a deviation by the signal measurement / comparison determination circuit 90. <Zweite Ausführungsform: Zusammenfassung>

[0047] In the load control system 1 according to the second embodiment, the signal measurement / comparison circuit 90 determines that the switching element 70 is in the energized state when the voltage level of the output 72 is lower than the first threshold voltage 87 and higher than the second threshold voltage 88. By using the second threshold voltage 88 in conjunction with the second threshold voltage, it is possible, in addition to determining whether the switching element 70 is in the energized state, to estimate whether current is actually flowing through the fuel injector 100 or not. As a result, the deviation detection accuracy of the load control system 1 can be improved.

[0048] In the load control system 1 according to the second embodiment, the excitation identification signal 81 can be used jointly for both disconnection detection and excitation identification, wherein the excitation identification signal 81 is configured by the output of the comparator 80 and the output of the comparator 85. Therefore, for example, if the control circuit 20 has a circuit configuration for detecting disconnection, this circuit configuration can be used to identify the excitation state of the switch element 70.

[0049] This means that there is an advantage in that the problem of the present invention can be solved without significantly altering the design of the control device 20. <Dritte Ausführungsform>

[0050] Fig. Figure 8 is another example of a time graph that explains the change over time of a signal value, which represents a result determined by the signal measurement / comparison circuit 90. The signal measurement / comparison circuit 90 results in the measurement result shown in the time graph. Fig. Figure 3 illustrates a comparative determination; however, the electronic control unit 10 can perform the comparative determination. The measurement procedure for each measured input signal is the same as that shown in Figure 3. Fig.3. However, in this case, it is necessary to store the measurement result for each measured input signal for each pulse in the register. Therefore, no arithmetic circuit is required to perform the comparison determination, nor is a register needed to store the determination result. However, a register for storing the measurement result, such as a response delay time, an injection timing time, and an excitation time, is additionally required.

[0051] Regarding the response delay time, the measurement result is stored in the numbered register each time a time is measured from the rise of an injection control signal 61 to the rise of an excitation identification signal 81. If, due to a deviation of a control device 20, the rise of the excitation identification signal 81 exceeds a threshold for a permissible delay of the response delay time with respect to the injection control signal 61, the measurement time at the time the time exceeds the threshold or the maximum response delay measurement time is stored in the register.

[0052] The injection timing of the injection control signal 61 for each pulse and the excitation time of the excitation identification signal 81 for each pulse are also stored in the numbered register each time the measurement is performed. If the rise of the excitation identification signal 81 does not appear due to a deviation of the control device 20, even if the threshold for a permissible response delay is exceeded, and the injection timing corresponding to a pulse of the injection control signal 61 ends, it is assumed that the excitation does not occur, and the excitation time can be set to "0" at a time when the measurement of the injection timing is complete.

[0053] If a drop in the excitation identification signal 81 does not appear due to a fixation of an output 72 of the control device 20 at a ground level or the like, the measurement of the excitation time on the corresponding pulse of the excitation identification signal 81 is completed at a time when the maximum measurement time is reached, and the excitation time can be stored in the register as the maximum measurement time.

[0054] The electronic control unit 10 compares the injection timing and the excitation time between register data with the same number. Therefore, for the injection control signal 61 and the excitation identification signal 81, which correspond to it, the measurement result must be stored in the register with the same number. In particular, if the excitation identification signal 81 rises within the threshold for a permissible delay after the injection control signal 61 has risen, both the excitation identification signal 81 and the injection control signal 61 should be paired and stored in the register with the same number.Furthermore, it is preferred that, depending on a transmission time specification of the communication interface 50, no incorrect determination is made by merely transmitting the updated data together with data to be compared or by adding a graphic showing the data, such that a mismatch between the number of injection control repetitions and the number of excitation repetitions or a mismatch between the injection control time and the excitation time does not occur. <Bezüglich Modifikationen der vorliegenden Erfindung>

[0055] The present invention is not limited to the embodiments described above, but includes various modifications. For example, the embodiments described above have been described in detail for a better understanding of the present invention and are not limited to the single embodiment that contains all the configurations described above. Furthermore, a component of the configuration of one embodiment can be replaced by that of another embodiment, and the configuration of one embodiment can be incorporated into the configuration of another embodiment. Additionally, a component of the configuration of each embodiment can be added to, deleted from, or replaced by that of a different configuration.

[0056] The electronic control unit 10 and the actuator 20 can jointly use and perform the comparison determination for each measurement object. For example, it is considered that the actuator 20 can perform the comparison determination on the response delay time or simply the measurement on the injection timing, the excitation time, the number of injection timing repetitions, and the number of excitation repetitions, and transmit the results to the electronic control unit 10, and so on.

[0057] Each of the configurations, functions, processing sections, processing units, or the like described above may be implemented partially or entirely in hardware, for example, by designing it through an integrated circuit. Furthermore, each of the configurations, functions, or the like described above may also be implemented in software, with a processor interpreting and executing a program to implement the respective functions. Information such as a program, table, file, or the like for implementing each of the functions may be provided in a recording device such as memory, a hard disk drive, or a solid-state drive (SSD), or may be provided in a recording medium such as an IC card, an SD card, or a DVD.Furthermore, control and data lines deemed necessary for the explanation are shown, although not all control and data lines are always shown for every product. It can be assumed that essentially all configurations are actually interconnected. List of reference symbols 10 Electronic control unit 20 Control device 30 CPU 31 Injection command 40 I / O connector 50 Communication interface 56 Measurement start triggers 60 Input signal determination circuit 61 Injection control signal 65 Gate control circuit 70 Switch element 71 Gate Entrance, 72 Exit 80, 85 comparator 81 Excitation identification signal 86 Excitation determination threshold voltage 87 first threshold voltage 88 second threshold voltage 90 Signal measurement / comparison circuit 91 Comparison result 100 Fuel injector 200 DC power supply

Claims

[1] Load control circuit comprising the following: a switching element (70) that controls a load (a fuel injector (100)); and a diagnostic unit which, based on a control command of the switch element (70) and a signal at an output terminal of the switch element (70), diagnoses a deviation in the response behavior of the switch element (70). an excitation identification signal generation unit that compares a voltage at the output terminal of the switching element (70) and a predetermined voltage threshold to distinguish whether the switching element (70) is in an excitation state or an open state or not, and outputs an excitation identification signal (81) that represents the discrimination result, wherein the diagnostic unit uses the excitation identification signal (81) to diagnose a delay time between the control command and the excitation identification signal (81) and / or an excitation time of the switching element (70) and / or the number of repetitions of the excitation of the switching element (70). [2] Load control circuit according to claim 1, further comprising: a terminal (40) that receives the control command from an electronic control unit (10) which transmits the control command; and a communication interface (50) that transmits data to and receives data from the electronic control unit (10), wherein the diagnostic unit transmits the diagnostic result to the electronic control unit (10) via the communication interface (50). [3] Load control circuit according to claim 1, further comprising: a terminal (40) that receives the control command from an electronic control unit (10) which transmits the control command; and a communication interface (50) that transmits data to and receives data from the electronic control unit (10), wherein the diagnostic unit transmits the diagnostic result obtained using the excitation identification signal (81) to the electronic control unit (10) via the communication interface (50). [4] Load control circuit according to claim 1, further comprising an excitation identification signal generation unit which compares a voltage at the output terminal of the switching element (70) and a predetermined voltage threshold to distinguish whether the switching element (70) is in an excitation state or an open state or not, and outputs an excitation identification signal (81) representing the distinction result, wherein the diagnostic unit uses the excitation identification signal (81) to diagnose the switching element (70) and uses the excitation identification signal (81) to determine whether a ground fault of the load occurs or not. [5] Load control circuit according to claim 4, wherein the diagnostic unit, during an interruption period in which the control command indicates that the switch element (70) is in an interruption state, uses the excitation identification signal (81) to determine whether the ground fault of the load occurs or not, and then, if it is determined that the ground fault of the load occurs during the interruption period, the diagnostic unit determines that the switch element (70) is excited in a different manner. [6] Load control circuit according to claim 1, further comprising an excitation identification signal generation unit which compares a voltage at the output terminal of the switching element (70) and a predetermined voltage threshold to distinguish whether the switching element (70) is in an excitation state or an open state or not, and outputs an excitation identification signal (81) representing the discrimination result, wherein the diagnostic unit uses the excitation identification signal (81) to diagnose the switching element (70), and uses the excitation identification signal (81) to determine whether a wiring connection for linking the load control circuit and the load is disconnected or not. [7] Load control circuit according to claim 6, wherein the diagnostic unit, during an interruption period in which the control command indicates that the switch element (70) is in an excitation state, uses the excitation identification signal (81) to determine whether the wiring is disconnected or not, and then, if it is determined that the wiring is disconnected during the excitation period, the diagnostic unit determines that the switch element (70) is differently excited during the excitation period in a period in which the wiring is not disconnected. [8] Load control circuit according to claim 1, wherein, after the control command has instructed the switching element (70) to be in an excitation state, the diagnostic unit determines whether a delay time until the switching element (70) is in the excitation state falls within a predetermined time window or not, and then, if the delay time does not fall within the time window, the diagnostic unit outputs a deviation indicator that indicates that the delay time does not fall within the time window. [9] Load control circuit according to claim 1, wherein the diagnostic unit determines a period of time during which the switch element (70) is in an excitation state, the diagnostic unit calculates a difference or ratio between a time for which the control command instructs that the switch element (70) is in the excitation state and a time for which the switch element (70) is in the excitation state, and Then, if the difference or ratio does not fall within a specified threshold value, the diagnostic unit issues a deviation indicator indicating that the difference or ratio does not fall within the specified threshold value. [10] Load control circuit according to claim 1, wherein the diagnostic unit determines the number of repetitions for which the switching element (70) is in an excitation state, the diagnostic unit calculates a difference between the number of repetitions for which the control command indicates that the switch element (70) is in the excitation state, and the number of repetitions for which the switch element (70) is in the excitation state, and Then, if the difference does not fall within a specified threshold value, the diagnostic unit issues a deviation indicator indicating that the difference does not fall within the specified threshold value. [11] Load control circuit according to claim 1, wherein the load is configured as an electrical load that opens and closes a fuel injection valve (100) that injects fuel into an internal combustion engine, The control command is a command to instruct the load to inject fuel. The control command is a command to specify an injection timing and injection time of the fuel into the internal combustion engine in a combustion cycle for one or more repetitions, and The load control circuit excites the load in such a way that the fuel injection valve (100) is opened and closed according to the control command. [12] Load control circuit according to claim 11, further comprising a storage device which stores the diagnostic result obtained from the diagnostic unit, wherein the diagnostic unit stores the diagnostic result in the storage device each time the control command specifies the injection time setting and the injection time. [13] Load control system comprising: the load control circuit according to claim 1; and an electronic control unit (10) that transmits the control command to the load control circuit. [14] Load control system according to claim 13, wherein the electronic control unit comprises: a connection (40) that transmits the control command to the load control circuit; and a communication interface (50) that receives the diagnostic result obtained from the diagnostic unit of the load control circuit.

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