JP2012005254A - Controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller capable of outputting various monitor signals with high degrees of freedom without providing an exclusive monitor signal terminal.SOLUTION: The controller 20 controls a control object based on a signal to be transmitted via a communication line S, and includes: a mode switching part 20a which shifts from a control mode for controlling the control object to an inspection mode when predetermined signal input is detected; and a communication part 20b which changes a signal form of the signal to be transmitted or received via the communication line from a first signal form to be used in the control mode to a second signal form different from the first signal form to perform communication when the controller shifts to the inspection mode by the mode switching part.

Description

  The present invention relates to a control device that includes a communication line to which an external device can be connected, and controls a control target based on a signal transmitted via the communication line.

  Many control devices equipped with microcomputers are incorporated in automobiles and the like. These control devices include a plurality of control devices of different types for controlling the same type of control object, and a control device appropriately selected according to the destination is assembled in the vehicle on the production line.

  Furthermore, in the production line, whether or not the control device assembled in the vehicle is a control device that matches the destination, and whether or not the control device is a failure-free control device that can appropriately perform the intended function. Inspection needs to be done.

  Therefore, a dedicated input / output terminal for serially communicating test data to a test device such as a RAM monitor is provided in the control device, and test data for testing the function of the microcomputer is transmitted from the test device. There is a case where a configuration is employed in which a response from a computer is received to check whether the operation is normal or abnormal.

  However, it is necessary to construct an additional circuit for realizing such a function inside the microcomputer, which disadvantageously increases the cost of the control device.

  Therefore, Patent Document 1 proposes a vehicle control microcomputer that does not require an external connection terminal dedicated to operation check and can perform operation check after mounting without incorporating a special test function.

  The vehicle control microcomputer is provided with input means for receiving an input signal necessary for electronic control of the vehicle engine, storage means for storing a program indicating the electronic control procedure, and the program and the input means. Control means for generating a control signal necessary for controlling the vehicle engine based on the input signal, and when a predetermined operation predetermined according to the program is performed in the control means, Pulse generating means for generating an operation monitoring pulse having a pulse width that does not affect the control of the vehicle engine, and the operation monitoring pulse generated by the pulse generating means is superimposed on the control signal generated by the control means. Pulse superimposing means for generating a synthesis control signal, and converting the synthesis control signal into a signal of a predetermined level for engine control and outputting it And an output means that.

  Further, Patent Document 2 proposes an automobile control device for the purpose of processing a diagnostic function and a special control for displaying a result thereof reliably and at high speed.

  The vehicle control device has a microcomputer built-in, and special control such as self-diagnosis is performed when a combination condition in which at least two or more of the input signals cannot occur in actual use is satisfied. Is executed and the result is displayed, and the special control is released by a power-on reset.

JP 2000-257500 A Japanese Patent Laid-Open No. 04-287854

  However, in the above-described prior art, each is not provided with a dedicated signal output terminal, but is configured to output a monitor signal also using an existing signal output terminal. Since the output form of the output signal is fixed, there is a problem that the monitor signal can be output only within the range of the signal output form.

  In addition, in order to increase the types of signals required for monitoring, it is necessary to increase the number of existing signal output terminals that are also used as monitor signal output terminals. If there are not many signal output terminals, the signal types are also limited. There is also a problem that detailed inspection becomes difficult.

  In view of the above-described problems, an object of the present invention is to provide a control device capable of outputting various monitor signals with a high degree of freedom without providing a dedicated monitor signal terminal.

  In order to achieve the above-described object, a characteristic configuration of a control device according to the present invention is a control device that controls an object to be controlled based on a signal transmitted via a communication line, and controls the control device when a predetermined signal input is detected. When the mode switching unit shifts from the control mode for controlling the object to the inspection mode and the mode switching unit shifts to the inspection mode, the signal form of the signal transmitted or received via the communication line is used in the control mode. And a communication unit that performs communication by changing the first signal form to a second signal form different from the first signal form.

  According to the above configuration, when a predetermined signal input is detected by the mode switching unit, the mode is switched from the control mode for controlling the controlled object to the inspection mode, and when the mode is switched to the inspection mode, the communication line is connected. The signal form of the signal transmitted or received is changed from the first signal form corresponding to the control mode by the communication unit to the second signal form different from the first signal form. Therefore, it becomes possible to transmit or receive various types of monitoring signals in a signal form having a high degree of freedom without being restricted by the signal form transmitted or received in the control mode.

  For example, the communication unit is configured to switch and communicate from a first communication system that transmits or receives a PWM signal as the first signal form to a second communication system that transmits a code signal as the second signal form. Preferably, in the control mode, the first communication method for transmitting or receiving an efficient PWM signal suitable for control is selected, but the inspection mode is switched to the second communication method for transmitting the code signal, and more than the control mode. This type of signal can be transmitted with various accuracies.

  As described above, according to the present invention, it is possible to provide a control device that can output various monitor signals with a high degree of freedom without providing a dedicated monitor signal terminal.

(A) is explanatory drawing in case the control apparatus by this invention is connected with an engine control apparatus, and operate | moves in control mode, (b) is the case where the control apparatus by this invention is connected with a test | inspection apparatus, and operate | moves in test mode Illustration (A) is explanatory drawing of the engine cooling device with which the control apparatus by this invention is used, (b) is a circuit diagram of the communication line and interface circuit which connect the control apparatus and engine control apparatus by this invention. (A) is explanatory drawing of a PWM signal, (b) is explanatory drawing of the 1st communication system which transmits a PWM signal as a 1st signal form, (c) is explanatory drawing of the 1st communication system which shows another embodiment. The circuit block block diagram of the control apparatus by this invention The flowchart which shows the process in the control mode performed by the control apparatus by this invention (A) is explanatory drawing of the sequence which the control apparatus by this invention transfers to test | inspection mode, (b) is explanatory drawing of the 2nd communication system which transmits a code signal as a 2nd signal form. Flow chart showing mode determination processing and inspection mode processing

  Hereinafter, a case where the control device according to the present invention is applied to a fan motor control system that controls an engine cooling device of a vehicle will be described as an example.

  As shown in FIG. 1A, the fan motor control system functions as a fan motor 10 and a control device of the present invention, and controls the fan motor 10 (hereinafter referred to as “fan motor ECU”). (ECU is an abbreviation for Electronic Control Unit.) 20 and an engine control device 30 (hereinafter referred to as “engine ECU”) that controls the engine and outputs a fan motor control signal to the fan motor ECU 20. It consists of

  The fan motor 10 includes a stator including three-phase coils (stator windings) of U, V, and W, and an outer rotor including a plurality of permanent magnets in which N poles and S poles are alternately arranged. It consists of a three-phase brushless DC motor.

  The fan motor ECU 20 is configured to operate with electric power supplied from the battery via the power line P, and to exchange signals with the engine ECU connected via the communication line S.

  The fan motor ECU 20 includes an inverter 23 that drives the fan motor 10, a pre-driver 25 that drives the inverter, and a microcomputer 21 that outputs a control signal to the pre-driver 25 to control the fan motor 10 at a target rotational speed. Yes.

  The microcomputer 21 is applied with a predetermined control voltage adjusted by a DC regulator 26 connected to the battery, and is preliminarily based on a PWM signal indicating a target rotational speed output from the engine ECU 30 received via the interface circuit IF. A control signal is output to the driver 25.

  As shown in FIG. 1B, the fan motor ECU 20 is further configured to be connectable to the inspection device 40 via the power line P and the communication line S.

  The inspection device 40 is a device for inspecting the destination and function of the fan motor ECU 20 after the fan motor ECU 20 is assembled to the vehicle in the manufacturing process.

  The fan motor ECU 20 executes control for inspection in response to a signal output from the inspection device 40 when the inspection device 40 is connected, and outputs a signal output from the engine ECU 30 when the engine ECU 30 is connected. In response, it operates to control the fan motor 10.

  FIG. 2A shows an engine cooling device for a vehicle to be controlled by the fan motor control system. The engine cooling device is disposed between the engine 1, a pipe line 2 that supplies cooling water to a water cooling jacket of the engine 1, a radiator 3 that dissipates cooling water heated by the engine 1, and the radiator 3 and the engine 1. The cooling fan 4 is provided.

  The radiator 3 includes a heat exchange core portion in which flat tubes and corrugated fins are combined, and a tank portion that plays a role of distributing and collecting cooling water to the tubes of the heat exchange core portion. The engine 1 and the radiator 3 are connected via a circulation line 2A, and a water pump 5 for circulating cooling water is disposed in the circulation line 2A.

  The high-temperature cooling water flowing into the radiator 3 is cooled by exchanging heat with the air attracted by the cooling fan 4 driven by the fan motor 10, and the cooling water cooled by the radiator 3 is used as an engine power or an electromagnetic motor. The water pump 5 is driven by the power of the water and is fed to the inlet 2a of the water-cooled jacket provided in the engine 1, and after heat exchange with the engine, the water-cooled jacket from the outlet 2b to the radiator 3 through the circulation line 2A. It is configured to reflux. A water temperature sensor 6 that detects the temperature of the cooling water heat-exchanged by the engine 1 is installed in the vicinity of the outlet 2b.

  In the middle of the circulation line 2A, a bypass line 2B that bypasses the radiator 3 and allows cooling water to flow is connected in parallel to the circulation line 2A. A thermostat 7 provided on the suction side of the water pump 5 switches whether the cooling water is allowed to flow through the bypass pipe 2B or the cooling water is allowed to flow through the radiator 3.

  The thermostat 7 is a temperature responsive valve, and opens and closes the pipe line by displacing the valve body using the volume change due to the temperature of the thermo wax. When the temperature of the cooling water rises to a set temperature set by the thermowax, the thermostat 7 opens the outlet side pipe of the radiator 3 and allows the cooling water to flow through the radiator 3 so that the temperature of the cooling water is lower than the set temperature. In this case, the cooling water is passed through the bypass pipe line 2B.

  The engine ECU 30 incorporates a microcomputer to control the engine, such as an operation signal of an ignition switch, an accelerator opening sensor that detects the depression amount of an accelerator pedal, an engine speed sensor, a vehicle speed sensor, and an air conditioner operation signal. Signals from various sensors required for the input are input via an input circuit.

  Based on these input values, the engine ECU 30 executes predetermined arithmetic processing by the CPU, and as a result, outputs a control signal for the throttle valve via the output circuit, and outputs a fuel injection signal and ignition to each cylinder at a predetermined timing. The engine is driven by outputting a signal.

  Further, the engine ECU 30 determines a target rotational speed of the fan motor 10 based on a predetermined arithmetic expression or control so that the cooling water is appropriately cooled by the radiator 3 based on the vehicle speed, the detected temperature of the cooling water by the water temperature sensor 6 and the like. Calculation is performed based on the map data, and the result is output to the fan motor ECU 20 as a PWM signal that is a fan motor control signal.

  FIG. 2B shows an interface circuit IF of the fan motor ECU 20 and the engine ECU 30 that transmit and receive signals via the communication line S. The engine ECU 30 drives the transistor Q3 of the interface circuit IF on the engine ECU 30 side, generates a PWM signal having a duty ratio corresponding to the target rotational speed, and outputs the PWM signal to the fan motor ECU 20.

  The fan motor ECU 20 receives the PWM signal via the transistor Q1 driven by the PWM signal transmitted via the communication line S. Further, the transistor Q2 is driven to transmit a predetermined signal to the engine ECU 30.

  FIG. 3A shows a PWM signal output from the engine ECU 30 to the fan motor ECU 20. The PWM signal is a signal that defines the number of rotations of the fan motor 10 by the ratio (Ton / T) of the on-time Ton to a predetermined pulse period T, that is, the duty ratio.

  In this embodiment, the pulse period T is 0.02 sec. The duty ratio is set between 15% and 85% so that the rotational speed of the fan motor can be linearly controlled in the range of 750 rpm to 3000 rpm. When the fan motor is stopped, the duty ratio is set in the range of 5% to 13%. Note that the duty ratio outside this range is not set to an effective range, and when a PWM signal in this range is received, the control of the fan motor 10 is ignored, or it is stopped, or the maximum rotation speed. It is possible to set so as to be treated as a value indicating that. Each numerical value mentioned above is an illustration, and is not limited to this value.

  FIG. 3B shows an example of the first communication method performed between the engine ECU 30 and the fan motor ECU 20 in the control mode. In the first communication method, a PWM signal as a first signal form is repeatedly output from the engine ECU 30 to the fan motor ECU 20 at a cycle of 50 Hz.

  The fan motor ECU 20 grasps the required rotation speed based on the PWM signal output from the engine ECU 30, and controls the start of the fan motor 10 so as to be the rotation speed. Further, fan motor ECU 20 transmits a signal of a predetermined self-diagnosis result to engine ECU 30 as necessary. For example, if it is determined as a result of self-diagnosis that no abnormality has occurred, the transistor Q2 is turned off, and a reception mode for exclusively receiving the PWM signal transmitted from the engine ECU 30 is entered. As a result of self-diagnosis, an abnormality has occurred. If determined, the transmission mode is set to turn on the transistor Q2 and notify the engine ECU 30 of the occurrence of abnormality.

  FIG. 3C shows another example of the first communication method. At the time of abnormality determination by the fan motor ECU 20, a PWM signal having a duty ratio corresponding to the determination result is transmitted from the fan motor ECU 2 to the engine ECU 30, and the type of abnormality can be identified based on the duty ratio. The pulse period of the PWM signal indicating the diagnosis result is set to the same value as the pulse period of the PWM signal that defines the rotation speed of the fan motor described above, but may be a different value.

  For example, between the engine ECU 30 and the fan motor ECU 2, which is longer than the pulse period T of the PWM signal (see FIG. 3A), for example, 100 msec. The PWM signal is alternately transmitted / received at a transmission interval Tdt of the order. In this case, if the priority of the transmission right is set to one of them, and transmission conflicts, the transmission with the lower priority is stopped for at least a certain time, and the transmission with the higher priority cannot be confirmed for a predetermined time. A signal is transmitted for a predetermined period.

  In the example of FIG. 3C, both of the PWM signals having three periods are set to 100 msec. It is set to transmit alternately at intervals of.

  FIG. 4 shows a detailed circuit block of the fan motor ECU 20. The fan motor ECU 20 includes a microcomputer 21, a noise filter 22, a U, V, W three-phase inverter 23, a rotational position detector 24, a pre-driver 25, a DC regulator 26, a voltage sensor 27, a temperature sensor 28, and an overcurrent detection. Part 29, an interface circuit IF and the like.

  The microcomputer 21 includes a CPU, a ROM, a RAM, an input / output circuit, and the like. When a predetermined signal input is detected by a CPU that executes a control program stored in the ROM, the microcomputer 21 switches from the control mode for controlling the fan motor 10 to the inspection mode. When the mode is switched to the inspection mode by the mode switching unit 20a and the mode switching unit 20a, the signal form of the signal transmitted or received via the communication line S is changed from the first signal form to the first signal form used in the control mode. A communication unit 20b that performs communication by changing to a different second signal form, a drive control unit 20c that drives the fan motor 10 in the control mode and diagnoses whether the fan motor 10 is operating normally, and an inspection mode Thus, the inspection control unit 20d for executing the inspection control is realized.

  In a state where the above-described inspection device 40 is not connected to the fan motor ECU 20, the mode switching unit sets the control mode. Hereinafter, the operation of the fan motor ECU 20 in the control mode will be described.

  A voltage of DC 12 V is supplied from the battery Bat to the three-phase inverter 23 via the noise filter 22. The inverter 23 includes switching elements made of three FETs or transistors on the high side and the low side, respectively.

  When the ignition switch IGSW is turned on, a voltage of about DC 12 V is supplied from the battery Bat to the DC regulator 26, and a voltage of DV 5 V adjusted by the DC regulator 26 is applied to the microcomputer 21. At this time, a power-on reset is applied to the microcomputer 21, and after the reset is released, the control program stored in the ROM is sequentially read and executed by the CPU.

  The mode switching unit 20a sets either the normal control mode or the inspection mode based on a signal input via the communication line S.

  FIG. 5 shows a flowchart when the control mode is set. When the ignition switch IGSW is turned on, the drive control unit 20c stands by in a state where the fan motor 10 can be started, and waits for a PWM signal output from the engine ECU 30 (SA1).

  When a PWM signal is received from the engine ECU 30 (SA1), a start determination is made based on the PWM signal, and if there is no start request (SA2), the fan motor 10 is controlled to stop (SA6), and if a start request is made ( SA2) A target rotation speed is calculated, and fan motor drive control is executed to output a PWM signal for controlling the rotation speed of the fan motor 10 to the target rotation speed to the pre-driver 25 (SA3).

  When each switching element is driven in a predetermined pattern by the pre-driver 25, a rotating magnetic field is generated in the three-phase coils of U, V, and W of the fan motor 10, and the rotor rotates in synchronization with the rotating magnetic field. .

  Specifically, the high-side and low-side switching elements are driven, and U → W, U → V, W → V, and W → with respect to predetermined two phases of the three-phase coils U, V, and W. By repeatedly applying current in the order of U, V → U, and V → W, the rotor is rotationally driven in the positive direction.

The duty ratio of the PWM signal output to the pre-driver 25 is set by PI control calculation for the deviation between the target rotational speed instructed from the engine ECU 30 and the rotational speed of the rotor calculated based on the output signal of the rotational position detector 24. Is done. When the deviation between the rotational speed of the rotor and the target speed is ΔV, the duty ratio Dn of the PWM signal output to the pre-driver 25 is calculated by the following formula. However, D (n-1) is the previous duty ratio, and Kp and Ki are control constants.
Dn = D (n−1) + Kp × ΔV + Ki × ∫ΔV

  The rotational position detector 24 includes three comparators COM that compare the voltages induced in the U, V, and W phases with the reference voltage Vref. When current is applied to predetermined two phases of the three-phase coils U, V, and W of the brushless motor, the remaining one phase interlinks with the magnetic flux of the permanent magnet provided in the rotor as the rotor rotates. An induced voltage is generated in

  The comparator COM compares the voltage induced in each coil U, V, W with the reference voltage Vref, and is configured such that its output logic changes at the zero crossing point where the induced voltage intersects the reference voltage Vref. Yes. The rotational position of the rotor is detected based on the zero cross signal corresponding to this induced voltage. Here, the reference voltage Vref is set to 1/2 of the battery voltage, that is, 1/2 of the voltage applied to each phase coil.

  The microcomputer 21 detects the rotational position of the rotor based on the energized state of each coil U, V, W and the zero cross point of each coil detected based on the output signal from the comparator, and each phase. The rotation direction of the rotor is detected based on the generation order of the zero cross signal, and the rotation speed of the rotor is calculated based on the cycle of the zero cross. That is, the rotational position detector 24 can determine the rotational position, rotational direction, and rotational speed of the rotor without providing a sensor such as a hall element to detect the rotational position of the rotor.

  The drive control unit 20c further performs self-diagnosis control on the fan motor ECU 20 during execution of fan motor drive control (SA4). The voltage sensor 27 includes a resistance voltage dividing circuit that detects the output voltage of the battery Bat, and the output voltage is input to the microcomputer 21. The drive control unit diagnoses a battery voltage abnormality when the fan motor 10 cannot be driven properly due to an abnormal drop in the output voltage of the battery Bat.

  In the control mode, the output voltage of the battery Bat is determined to be within the range of DC9V to DC16V, and if it is less than DC9V, it is determined to be in an abnormally low voltage state, and if higher than DC16V, it is determined to be in an abnormally high voltage state.

  The temperature sensor 28 is provided to detect the temperature of the three-phase inverter 23, is constituted by a thermistor, a thermocouple, or the like, and its output voltage is input to the microcomputer 21. When the three-phase inverter 23 reaches an abnormally high temperature, the drive control unit controls the fan motor 10 to stop and diagnoses a high temperature abnormality.

  The overcurrent detection unit 29 is configured by an amplifier circuit that converts currents flowing through the coils U, V, and W of the fan motor 10 into voltages via the three-phase inverter 23, and the output voltage is input to the microcomputer 21. Yes. When the overcurrent detection unit 29 detects that an overcurrent has flowed into the fan motor 10, the drive control unit controls the fan motor 10 to stop and diagnoses an overcurrent abnormality.

  The drive control unit 20c further diagnoses a fan motor abnormality when the detected deviation between the rotational speed and the target speed exceeds a predetermined value for a predetermined time.

  If the drive control unit 20c determines that there is an abnormality as a result of the self-diagnosis, it drives the transistor Q2 of the interface circuit IF and outputs an abnormality occurrence signal to the engine ECU 30 (SA5). When the engine ECU 30 receives the abnormality occurrence signal via the communication line S, the warning display indicating the fan motor abnormality is turned on on the display unit to notify the driver of the failure. When the example of FIG. 3B is adopted as the first communication method, the signal line S is fixed at a low level at the time of abnormality determination, so that the PWM signal output from the engine ECU 30 is received by the fan motor ECU 20. The fan motor 10 is stopped by the drive control unit 20c.

  FIG. 6 shows a timing chart of the mode determination process by the mode switching unit 20a. The inspection apparatus includes a power supply, a control unit, and the like that can variably set a voltage applied via the power supply line P in a range of DC0V to DC18V. The inspection device connected to the fan motor ECU 20 applies a voltage having a value that deviates from the appropriate voltage range in the control mode to the fan motor ECU 20 via the power line P, and the appropriate value in the control mode via the communication line S. A PWM signal having a duty ratio deviating from the duty ratio of the PWM signal in a linear control range is output at a cycle having a value different from the pulse cycle in the control mode.

  The reason why the signal value in the range that deviates from the appropriate range of the signal value in the control mode is employed is to reliably eliminate the occurrence of an abnormal state that erroneously operates in the inspection mode in the control mode.

  The inspection apparatus connected to the fan motor ECU 20 applies DC7V that deviates from the appropriate voltage range via the power line P as a first condition at least at a time T1 (50 msec.) From point A to point B, It is configured to output a PWM signal with a duty ratio of 90% that deviates from the duty ratio of an appropriate PWM signal through the communication line S at 100 Hz. Further, at time T2 (50 msec.) From point B to point C, as a second condition, DC18V is applied via the power line P, and a PWM signal having a duty ratio of 10% is set via the communication line S at 100 Hz. Output.

  These signals are received by the communication unit operating in the first communication method for receiving the PWM signal, and the communication line S is driven to a low level by the mode switching unit in response thereto.

  When the inspection apparatus detects that the communication line S is driven to a low level at the point D, the inspection apparatus applies DC12V via the power line P as a third condition. When the mode switching unit detects that the voltage of the power supply line P has changed to DC 12 V, the mode switching unit switches from the control mode to the inspection mode to start the inspection control unit, and switches the communication method of the communication unit to the second communication method.

  After that, predetermined monitor information is generated by the inspection control unit, and the code signal in the second signal form is transmitted to the inspection apparatus by the communication unit from the F point to the G point after the elapse of time T3 (10 msec.). After that, the communication method of the communication unit is switched to the first communication method.

  FIG. 6B illustrates a code signal in the second signal form transmitted by the second communication method. As the second communication method, for example, an asynchronous serial communication method with a data transmission rate of 19.2 Kbps is adopted.

  The second signal form is composed of a code signal having 1 start bit, 8 data bits, and 1 stop bit as a unit, and a series of inspection information is transmitted by a plurality of code signals. Specifically, the number of data indicating the number of code signals to be transmitted is set to the data bits of the first code signal, each code is set to the data bits of the second and subsequent code signals, and the data bits of the last code signal Is set to the checksum.

  Returning to FIG. 6A, the inspection apparatus receives a code signal, and at point H after the elapse of time T4 (50 msec.), As a fourth condition, PWM with 100 Hz and a duty ratio of 50% is set via the communication line S. The signal is output for time T5 (50 msec.). When the mode switching unit determines that the PWM signal has continued for half of time T5 at point I, it drives the communication line S to the low level for time T6 (50 msec.) Until point J. When the inspection apparatus detects this, the inspection is terminated, and if there is a necessary inspection, the sequence from the point A is repeated.

  As monitor information generated by the inspection control unit, version information of software ported to a microcomputer incorporated in the fan motor ECU 20 (this version information is a signal including an identification code indicating a model), a voltage sensor. 7 includes information such as a voltage value detected by 7, a temperature detected by the temperature sensor 28, and a current value detected by the overcurrent detection unit 29.

  The type of monitor information is defined by the duty ratio of the PWM signal transmitted from the point B to the point C from the inspection device. For example, version information is required for a PWM signal with a duty ratio of 10%.

  FIG. 7 shows a flow of the mode determination process by the mode switching unit 20a and the inspection mode in which the inspection control unit 20d operates. When the microcomputer 21 is turned on and a power-on reset is applied (SB1), the mode switching unit 20a determines whether or not the first condition for shifting to the control mode is satisfied (SB2). If one condition is not satisfied, the mode is set to the control mode and the normal control in step SB9 is executed. The normal control is the control described with reference to FIG.

  If the first condition continues for ½ or more of time T1 (SB2), it is determined whether the second condition is satisfied (SB3), and the second condition is not satisfied. Sets the mode to the control mode and executes the normal control in step SB9.

  If the second condition continues for ½ or more of the time T2 (SB3), the voltage of the communication line S is switched to a low level (SB4), and then within a predetermined time TF1 (for example, 50 msec.). It is determined whether or not the third condition is satisfied (SB5). When the third condition is satisfied, the code of the second signal form is transmitted from the communication unit 20b that has switched from the first communication method to the second viewing method. The monitor information which is a signal is output (SB6). If the third condition is not satisfied within the predetermined time TF1, an error is determined and the control mode is shifted to the normal control mode (SB9).

  The monitor information is specified by the duty ratio of the PWM signal included in the second condition, and the inspection control unit 20d specifies and acquires necessary monitor information based on the duty ratio of the PWM signal included in the second condition.

  Thereafter, the communication unit 20b is switched to the first communication method to determine whether or not the fourth condition is satisfied (SB7). When the fourth condition is satisfied, the voltage of the communication line S is set to a low level. Switch (SB8). Further, after outputting the monitor information, if the fourth condition is not satisfied within a predetermined time TF2 (for example, 50 msec.), An error determination is made that the monitor information has not been properly received by the inspection apparatus, and the normal control mode is set. (SB9). Thereafter, the same processing is repeated.

  That is, the control object of the control device according to the present invention is a fan motor that drives a cooling fan of a vehicle, and the PWM signal received via the communication line S in the control mode is a signal indicating the target rotational speed of the fan motor, The code signal transmitted through the communication line S in the mode is a signal including an identification code indicating the model of the fan motor ECU 20.

  Further, when the mode switching unit determines that the cycle and the duty ratio of the PWM signal received via the communication line S are a predetermined combination different from the combination of the cycle and the duty ratio specified in the control mode, And the control is performed when it is determined that the voltage value of the DC voltage applied to the fan motor ECU 20 is a voltage value in a voltage range different from the voltage range defined in the control mode. It is configured to shift from the mode to the inspection mode.

  In the above-described embodiment, when the mode switching unit detects a predetermined signal input from the voltage sensor 27 and a predetermined signal input via the communication line S, the mode switching unit shifts from the control mode for controlling the control target to the inspection mode. However, the present invention is not limited to such a mode. The detection mode is changed from the control mode in which the control target is controlled when a predetermined signal input is detected through an arbitrary signal input terminal. What is necessary is just to be comprised so that it may transfer to.

  It should be noted that each of the above-described embodiments is merely an example of the present invention, and it is needless to say that the specific configuration and the like of each block can be appropriately changed and designed within the scope of the effects of the present invention.

1: Engine 2: Pipeline 3: Radiator 4: Cooling fan 6: Water temperature sensor 10: Fan motor 20: Control device (fan motor control device)
20a: mode switching unit 20b: communication unit 20c: drive control unit 20d: inspection control unit 21: microcomputer 22: noise filter 23: three-phase inverter 24: rotational position detection unit 25: pre-driver 26: DC regulator 27: voltage sensor 29: Overcurrent detection unit 30: Engine control device

Claims (5)

A control device that controls a control object based on a signal transmitted via a communication line,
A mode switching unit that shifts from a control mode for controlling the control target to an inspection mode when detecting a predetermined signal input;
When the mode switching unit shifts to the inspection mode, the signal form of the signal transmitted or received via the communication line is changed from the first signal form used in the control mode to the second signal form different from the first signal form. A communication unit that performs communication by changing, and
A control device comprising:   2. The control according to claim 1, wherein the communication unit performs communication by switching from a first communication system that transmits or receives a PWM signal as the first signal form to a second communication system that transmits a code signal as the second signal form. apparatus.   The control object is a fan motor that drives a cooling fan of a vehicle, and a PWM signal received via the communication line in the control mode is a signal indicating a target rotational speed of the fan motor, and the communication is performed in the inspection mode. The control device according to claim 2, wherein the code signal transmitted via the line is a signal including an identification code indicating a type of the control device.   When the mode switching unit determines that the cycle and duty ratio of the PWM signal received via the communication line is a predetermined combination different from the cycle and duty ratio combination defined in the control mode, the control The control device according to claim 1, wherein the control mode is shifted from the mode to the inspection mode.   When the mode switching unit determines that the voltage value of the DC voltage applied to the control device is a voltage value in a voltage range different from the voltage range defined in the control mode, the mode switching unit performs the inspection from the control mode. The control device according to claim 4 which shifts to a mode.

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