Load driving system

Abstract

To provide a load drive system capable of reducing an amount of communication.SOLUTION: A load drive system 14 includes a communication bus 20, a control device 30, and a drive device 40. The control device 30 includes a CAN transceiver 32 and a CAN controller 34 that transmit a message indicating a drive state of a solenoid 13 of an automatic transmission 10 via the communication bus 20. The drive device 40 includes a CAN transceiver 44 and a CAN controller 45 that receive the indication message via the communication bus 20, and a drive circuit 41 that drives the solenoid 13 according to the received indication message. The control device 30 transmits a first periodic message in a first cycle and transmits a second periodic message in a second cycle, as the indication message.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The disclosure in this specification relates to a load driving system.

Background Art

[0002] Patent Document 1 discloses a load driving system including a control device and a driving device. The description of the prior art document is incorporated herein by reference as an explanation of the technical elements in this specification.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, the driving device has a decoder to which a driving instruction for the load is input from the control device, and a driving circuit that drives the load according to the signal converted by the decoder. With such a configuration, the driving instruction is transmitted from the control device at a fixed period. Therefore, if a plurality of driving instructions are to be transmitted, there is a risk of an increase in communication volume. From the above viewpoints, or from other viewpoints not mentioned, further improvement of the load driving system is required.

[0005] One disclosed object is to provide a load driving system capable of reducing communication volume.

Means for Solving the Problems

[0006] The load driving system disclosed herein is a communication bus (20), and A control-side communication unit (32, 34) that transmits an instruction message indicating the driving state of a load (10) via a communication bus, and the control-side communication unit transmits a first instruction message in a first cycle and a second instruction message in a second cycle different from the first cycle as the instruction message, and a control device (30); A driving device (40) including a driving-side communication unit (44, 45) that receives an instruction message via a communication bus, and a driving circuit (41) that drives a load according to the received instruction message; The control device includes a microcomputer. The driving device does not include a microcomputer, receives an instruction message indicating the calculation result of the microcomputer included in the control device via a communication bus, and drives the load according to the calculation result. and The control device includes a determination unit (S40) that determines whether or not an abnormality has occurred in the load based on the state of the load acquired from the outside. The control-side communication unit transmits an instruction message according to a pre-associated priority order. When the determination unit determines that an abnormality has occurred, the control-side communication unit transmits an abnormality processing message with a higher priority than the instruction message to the drive device via the communication bus.

[0007] According to the disclosed load driving system, the control device transmits a first instruction message in a first cycle, and thereby the driving device drives the load according to the first instruction message. The control device transmits a second instruction message in a second cycle different from the first cycle, and thereby the driving device drives the load according to the second instruction message. The control device transmits each instruction message at a timing required for control, rather than transmitting all instruction messages at the earliest transmission cycle. As a result, a load driving system capable of reducing communication traffic can be provided.

[0008] The plurality of aspects disclosed in this specification adopt different technical means to achieve their respective purposes. The reference numerals in parentheses described in the claims and this section exemplify the correspondence with the parts of the embodiments described later, and are not intended to limit the technical scope. The objects, features, and effects disclosed in this specification will become clearer by referring to the subsequent detailed description and the accompanying drawings.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0010] Hereinafter, a plurality of embodiments will be described with reference to the drawings. In each embodiment, the same reference numerals are given to corresponding components, and redundant explanations may be omitted in some cases. When only a part of the configuration is described in each embodiment, for the other parts of the configuration, the configuration of other embodiments described previously can be applied. Also, not only the combinations of configurations explicitly shown in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined with each other as long as there is no problem with the combination, even if not explicitly shown.

[0011] (First Embodiment) The load driving system according to this embodiment can be applied to a load mounted on a vehicle, for example. Hereinafter, an example of its application to an automatic transmission of a vehicle will be described.

[0012] <Automatic Transmission> First, based on FIG. 1, the schematic configuration of the automatic transmission will be described. FIG. 1 shows an automatic transmission to which the load driving system according to this embodiment is applied. In FIG. 1, the automatic transmission is denoted as T / M, and the valve body is denoted as V / B.

[0013] As shown in FIG. 1, the automatic transmission 10 includes a valve body 11, a transmission mechanism (not shown), an oil pump, a parking lock mechanism, and the like. The transmission mechanism has a plurality of friction elements such as clutches and brakes, for example. The transmission mechanism can change the gear ratio stepwise by selectively engaging each friction element.

[0014] An oil pressure circuit for regulating the pressure of the hydraulic oil supplied to the transmission mechanism is formed in the valve body 11. The valve body 11 has a plurality of solenoid valves 12 that regulate the hydraulic oil pumped from the oil pump and supply it to the friction elements. In FIG. 1, for the sake of convenience, only one solenoid valve 12 is shown. The solenoid valve 12 has a solenoid 13. The solenoid 13 may be referred to as a coil. By controlling the energization of the solenoid 13, the hydraulic oil is regulated.

[0015] <Load Driving System> Next, based on FIGS. 1, 2, and 3, the schematic configuration of the load driving system will be described. FIG. 2 is a diagram showing the load driving system. In FIG. 2, for the sake of convenience, the illustration of the monitoring microcomputer is omitted. Also, the energization path of the solenoid 13 is simplified. FIG. 2 shows an example in which the valve body 11 has n (n ≧ 3) solenoids 13 including solenoids 131 to 13n. FIG. 3 is a diagram showing the drive circuit of the driving device. In FIG. 3, for the sake of convenience, only the solenoid drive circuit and the current detection circuit corresponding to one solenoid 13 among the solenoid drive circuit and the current detection circuit are illustrated.

[0016] In FIGS. 1 and 2, the microcomputer is shown as MC, and the drive circuit is shown as DC. In FIGS. 2 and 3, the PWM output circuit is shown as PWM, the solenoid drive circuit as SOLD, the current detection circuit as CD, and the cutoff circuit as PSC. In FIG. 2, the CAN controller is shown as CTR, and the CAN transceiver is shown as TRC. Also, the sensor detection circuit is shown as SEND, the hydraulic pressure sensor as OPS, the rotation sensor as RS, and the oil temperature sensor as OTS. In FIG. 3, the A / D converter is shown as ADC.

[0017] As shown in FIGS. 1 and 2, the load driving system 14 includes at least a communication bus 20, a control device 30, and a driving device 40. The load driving system 14 controls the driving of the load. The load to be controlled is an automatic transmission 10 including a solenoid 13 and thus a valve body 11. Among the load driving system 14, the driving device 40 is disposed on the valve body 11. That is, the driving device 40 has an electromechanical integrated structure with the automatic transmission 10. The control device 30 is mechanically separated from the automatic transmission 10.

[0018] The control device 30 and the drive device 40 are connected to a common communication bus 20. Devices (not shown) different from the control device 30 and the drive device 40 may be connected to the communication bus 20. In the present embodiment, the control device 30 and the drive device 40 are configured to be able to communicate with each other via the communication bus 20 of an in-vehicle network compliant with the CAN protocol. The communication bus may be referred to as a CAN bus. CAN is an abbreviation of Controller Area Network. CAN is a registered trademark.

[0019] In the load drive system 14 of the present embodiment, the messages transmitted by the control device 30 and the drive device 40 have predetermined priorities according to the importance and type of the messages. When transmitting each message, first, priority information (ID code) indicating the priority of each message is transmitted. At this time, when the transmission of the priority information of a plurality of messages conflicts, arbitration of the respective priority information is performed so that the priority information with a higher priority acquires the transmission right.

[0020] The control device 30 includes a microcomputer 31 and a CAN transceiver 32. The microcomputer 31 is a microcomputer including a CPU 33, a CAN controller 34, a ROM, a RAM, registers (not shown), and the like. In the microcomputer 31, the CPU 33 executes various controls according to a control program stored in advance in the ROM while using the temporary storage functions of the RAM and the registers. The CPU 33 executes control using data acquired from outside the control device 30, for example, a detection signal of a sensor. The CPU 33 of the present embodiment executes control of the solenoid 13 and thus the automatic transmission 10.

[0021] The CPU 33 of the microcomputer 31 executes a predetermined calculation to set a target current value. The target current value is the current value to be passed through the solenoid 13 in order to bring the solenoid 13 to the target state. The microcomputer 31 acquires the state of the automatic transmission 10 and calculates a target hydraulic pressure which is the required value of the output hydraulic pressure of the solenoid 13. The microcomputer 31 calculates the target hydraulic pressure based on, for example, the rotational speed on the input side and the rotational speed on the output side of the automatic transmission 10. The microcomputer 31 sets the target current value based on the calculated target hydraulic pressure. The relationship between the target hydraulic pressure and the target current value is predetermined, for example, as a map or a function. The control device 30 instructs the drive device 40 of the target current value.

[0022] The CPU 33 of the microcomputer 31 sets the duty ratio based on the state of the automatic transmission 10. The microcomputer 31 sets the duty ratio in order to suppress current fluctuations such as overshoot and current ripple at the initial stage of shifting. The duty ratio is the duty ratio of the PWM signal output to the gate of the drive switch 4111 described later. The microcomputer 31 sets the duty ratio based on, for example, at least one of the pressure of the hydraulic oil in the hydraulic circuit, the temperature of the hydraulic oil, and the actual current value flowing through the solenoid 13. The control device 30 instructs the drive device 40 of the duty ratio. The control device 30 may instruct the duty ratio during the period when the power supply of the control device 30 is turned on, or may instruct the duty ratio only during a temporary period such as the initial stage of shifting.

[0023] The CPU 33 of the microcomputer 31 determines whether an abnormality has occurred based on the state of the automatic transmission 10. The microcomputer 31 compares, for example, the pressure of the hydraulic oil with a hydraulic pressure threshold value to determine whether an abnormality has occurred. The microcomputer 31 compares, for example, the temperature of the hydraulic oil with a temperature threshold value to determine whether an abnormality has occurred. When it is determined that an abnormality has occurred, the control device 30 outputs an emergency instruction to the drive device 40 in order to set the energization to all the solenoids 13 to a predetermined abnormal treatment state. The control device 30 of the present embodiment outputs an emergency cutoff instruction to the drive device 40 in order to cut off the energization to all the solenoids 13 as an emergency instruction.

[0024] The microcomputer 31 incorporates a CAN controller 34 for transmitting and receiving messages via the communication bus 20. The CAN controller 34 executes communication control according to the CAN protocol. The CAN controller 34 executes, for example, transmission control, reception control, and arbitration control.

[0025] The CAN transceiver 32 is electrically connected to the CAN controller 34 and also electrically connected to the communication bus 20. The CAN transceiver 32 enables bidirectional transmission of communication messages between the communication bus 20 and the CAN controller 34 by mutually converting the electrical characteristics between the communication bus 20 and the CAN controller 34. For example, by converting the bus-level signal of the communication bus 20 into a digital signal that the CAN controller 34 can handle, dominant and recessive can be recognized. That is, the CAN controller 34 can transmit and receive communication messages with the communication bus 20 by being connected to the communication bus 20 via the CAN transceiver 32.

[0026] The CAN controller 34 has a message box for storing messages. The CAN controller 34 has a transmission message box 341 and a reception message box 342. The CAN controller 34 sequentially stores the transmission messages acquired via the communication interface in the message box 341. The CAN controller 34 performs transmission processing on the stored messages according to the priority of the ID code. The CAN controller 34 generates a frame based on the message stored in the message box 341 and transmits it to the communication bus 20 via the CAN transceiver 32. In the present embodiment, at least one of the frames for transmitting messages includes instructions for a plurality of solenoids 13 in a 64-bit data field.

[0027] The CAN controller 34 receives a frame from the communication bus 20 via the CAN transceiver 32, extracts a message or the like, and sequentially stores it in the message box 342. The CAN controller 34 outputs the received message as a transmission target according to the priority of the ID code. The CAN controller 34 performs arbitration of the transmission right (bit - level non - destructive arbitration) when a frame collides on the communication bus 20. The CAN controller 34 also detects and notifies errors related to the transmission and reception of frames. The CAN transceiver 32 and the CAN controller 34 correspond to the control - side communication unit.

[0028] The control device 30 may further include a microcomputer 35 as shown in FIG. 1. The microcomputer 35 monitors whether the microcomputer 31 is operating normally. The microcomputer 31 is called the main microcomputer, and the microcomputer 35 may be called the monitoring microcomputer. The microcomputer 35 monitors, for example, whether there are any watchdog abnormalities, communication abnormalities, or arithmetic function abnormalities in the microcomputer 31. In addition to the above - described monitoring function, the microcomputer 35 may have a function of assisting the control executed by the microcomputer 31. The microcomputer 35 may execute control different from that of the load driving system 14. The microcomputer 35 may also be configured to incorporate a CAN controller (not shown) and be capable of transmitting and receiving messages via the communication bus 20.

[0029] In this embodiment, the monitoring means of the microcomputer 31 is configured as the microcomputer 35, and the microcomputers 31 and 35 mutually monitor whether each is operating normally. The monitoring means of the microcomputer 31 is not limited to the microcomputer 35. Instead of the microcomputer 35, a monitoring IC may be provided. The control device 30 may be configured not to include monitoring means such as the microcomputer 35.

[0030] The drive device 40 does not include a microcomputer. The drive device 40 includes a drive circuit 41, a cutoff circuit 42, a sensor detection circuit 43, a CAN transceiver 44, and a CAN controller 45. The drive circuit 41 drives the solenoid 13 according to an instruction from the control device 30. As shown in FIGS. 2 and 3, the drive circuit 41 has a solenoid drive circuit 411, a current detection circuit 412, and a PWM output circuit 413. PWM is an abbreviation for Pulse Width Modulation.

[0031] As shown in FIG. 3, the solenoid drive circuit 411 has a drive switch 4111 connected in series to the corresponding solenoid 13. The drive switch 4111 is provided individually for the solenoid 13. The drive switch 4111 is provided on the energization path of the corresponding solenoid 13. The drive switch 4111 repeatedly turns on and off according to the PWM signal output from the PWM output circuit 413, connecting or disconnecting the solenoid 13 and the power supply. The solenoid drive circuit 411 has a plurality of drive switches 4111 to control the energization of a plurality of solenoids 13. The solenoid drive circuit 411 corresponds to a drive unit that drives the loads individually.

[0032] The drive switch 4111 may be provided on either the power supply side or the ground (GND) side with respect to the corresponding solenoid 13. The power supply side may be referred to as the high side (upstream side). The ground side may be referred to as the low side (downstream side). The drive switch 4111 of the present embodiment is provided on the power supply side with respect to the solenoid 13. In the present embodiment, a MOSFET is adopted as the drive switch 4111.

[0033] The current detection circuit 412 detects the current flowing through the solenoid 13, that is, the actual current. The current detection circuit 412 has a resistor 4121, an operational amplifier 4122, and an A / D converter 4123. The current detection circuit 412 is provided individually for the solenoid 13.

[0034] The resistor 4121 is connected in series to the corresponding solenoid 13. The resistor 4121 of this embodiment is provided on the ground side with respect to the solenoid 13. One end of the resistor 4121 is connected to the downstream terminal of the solenoid 13, and the other end of the end is grounded. In this way, the resistor 4121 is provided such that the voltage generated at both ends becomes a voltage corresponding to the current (actual current value) flowing through the solenoid 13.

[0035] The operational amplifier 4122 amplifies and outputs the voltage applied across the resistor 4121. The positive input terminal of the operational amplifier 4122 is connected to the upstream terminal of the resistor 4121. The negative input terminal of the operational amplifier 4122 is connected to the downstream terminal of the resistor 4121.

[0036] The A / D converter 4123 A / D-converts and outputs the output of the operational amplifier 4122, that is, the actual current value. The input terminal of the A / D converter 4123 is connected to the output terminal of the operational amplifier 4122.

[0037] The PWM output circuit 413 generates a PWM signal according to an instruction from the control device 30 and outputs it to the gate of the drive switch 4111. The PWM output circuit 413 generates PWM signals for a plurality of drive switches 4111 according to a single instruction message transmitted from the control device 30. The PWM output circuit 413 is a circuit that executes feedback control so that the actual current value detected by the current detection circuit 412 follows the target current value acquired from the control device 30 via the communication bus 20, and has a circuit for setting the duty ratio.

[0038] The feedback control circuit has a circuit that calculates the deviation (current deviation) between the target current value and the actual current value, and a circuit that calculates the duty ratio. The duty ratio calculation circuit is configured to execute, for example, PID control. In this case, the duty ratio calculation circuit has a circuit that calculates a duty ratio proportional to the deviation, a circuit that calculates a duty ratio proportional to the integral value of the deviation, a circuit that calculates a duty ratio proportional to the differential value of the deviation, and a circuit that calculates the sum of the duty ratios.

[0039] The duty ratio setting circuit sets the duty ratio of the PWM signal. The duty ratio setting circuit includes, for example, a register. The duty ratio calculation circuit sets the calculated duty ratio in the register. When the PWM output circuit 413 acquires an instruction of the duty ratio from the control device 30 via the communication bus 20, it sets the acquired duty ratio in the register. The duty ratio setting circuit generates a PWM signal with the duty ratio set in the register at a predetermined driving frequency and outputs it to the gate of the drive switch 4111.

[0040] The cutoff circuit 42 controls the on / off of the power supply switch 15. As shown in FIGS. 2 and 3, the power supply switch 15 is provided in the energization path of the solenoid 13. A single (common) power supply switch 15 is provided for a plurality of solenoids 13. The power supply switch 15 controls the energization to all the solenoids 13. When the power supply switch 15 is turned on, current can be supplied to each solenoid 13. When the power supply switch 15 is turned off, the supply of current to each solenoid 13 is cut off.

[0041] The power supply switch 15 may be provided either on the power supply side or the ground side with respect to the solenoid 13. The power supply switch 15 of the present embodiment is arranged on the power supply side. The power supply switch 15 is provided on the power supply side (upstream side) from the connection point of each solenoid 13.

[0042] The cutoff circuit 42 drives the power supply switch 15 according to the IG (Ignition) signal. When the IG switch of the vehicle is turned on and an IG on signal is input, the cutoff circuit 42 turns on the power supply switch 15. When the IG switch is turned off and an IG off signal is input, the cutoff circuit 42 turns off the power supply switch 15. When an emergency instruction is input from the control device 30 during the period when the IG on signal is input, the cutoff circuit 42 of the present embodiment turns off the power supply switch 15.

[0043] The sensor detection circuit 43 detects the signal of the sensor 16. The sensor detection circuit 43 performs predetermined processing, such as waveform detection, A / D conversion, etc. on the input signal from the sensor 16. The sensor 16 detects the state of the load, that is, the state of the automatic transmission 10 including the valve body 11. The sensor 16 of the present embodiment has a hydraulic pressure sensor 161, a rotation sensor 162, and an oil temperature sensor 163. The hydraulic pressure sensor 161 detects the pressure of the hydraulic oil in the hydraulic circuit. The rotation sensor 162 detects the rotational speed of the automatic transmission 10. The rotation sensor 162 includes, for example, a sensor that detects the rotational speed on the input side of the automatic transmission 10 and a sensor that detects the rotational speed on the output side. The oil temperature sensor 163 detects the temperature of the hydraulic oil in the hydraulic circuit.

[0044] The CAN transceiver 44 is electrically connected to the CAN controller 45 and is also electrically connected to the communication bus 20. The CAN transceiver 44 enables the two-way transmission of communication messages between the communication bus 20 and the CAN controller 45 by mutually converting the electrical characteristics between the communication bus 20 and the CAN controller 45. The CAN controller 45 can transmit and receive communication messages with the communication bus 20 by being connected to the communication bus 20 via the CAN transceiver 44.

[0045] The CAN controller 45 has a message box for storing messages. The CAN controller 45 has a transmission message box 451 and a reception message box 452. The CAN controller 45 sequentially stores the transmission messages acquired via the communication interface in the message box 451. The CAN controller 45 performs transmission processing on the stored messages according to the priority of the ID codes. The CAN controller 45 generates a frame based on the message stored in the message box 451 and transmits it to the communication bus 20 via the CAN transceiver 44.

[0046] The CAN controller 45 receives a frame from the communication bus 20 via the CAN transceiver 44, extracts messages and the like, and sequentially stores them in the message box 452. The CAN controller 45 outputs the received messages as transmission targets according to the priority of the ID codes. The CAN controller 45 arbitrates the transmission right when frames collide on the communication bus 20. The CAN controller 45 also detects and notifies errors related to the transmission and reception of frames. The CAN transceiver 44 and the CAN controller 45 correspond to the drive-side communication unit.

[0047] The drive device 40 is configured to enable communication, for example, SPI communication, between the CAN controller 45, the drive circuit 41, the cutoff circuit 42, and the sensor detection circuit 43. SPI is an abbreviation for Serial Peripheral Interface.

[0048] The load drive system 14 may further include at least one of the above-described power supply switch 15 and sensor 16. For example, the load drive system 14 may include both the power supply switch 15 and the sensor 16. The load drive system 14 may be configured such that it does not include the power supply switch 15 and the sensor 16, and the power supply switch 15 and the sensor 16 are arranged outside the load drive system 14.

[0049] <Operation of Load Drive System> Next, based on FIGS. 4 to 9, the operation of the load driving system 14 will be described. FIG. 4 is a timing chart showing the relationship between various messages transmitted over time in the load driving system 14. FIG. 5 is a flowchart showing the transmission process of the reference message executed by the control device 30. FIG. 6 is a flowchart showing the transmission process of the first periodic message executed by the control device 30 and the driving device 40. FIG. 7 is a flowchart showing the transmission process of the second periodic message executed by the control device 30. FIG. 8 is a flowchart showing the process executed by the control device 30 in response to the occurrence of a predetermined event. FIG. 9 is a flowchart showing the transmission and reception process of the messages executed by the control device 30 and the driving device 40. In FIGS. 5 to 9, the message box is shown as MB.

[0050] First, based on FIGS. 4 and 5, the transmission process of the reference message executed by the control device 30 will be described.

[0051] First, the CAN controller 34 of the control device 30 transmits the reference message to the communication bus 20 via the CAN transceiver 32 (step S10). The reference message has a higher priority of the ID code than the first periodic message. The reference message triggers the transmission of the first periodic message described later.

[0052] Next, the microcomputer 31 starts counting the elapsed time from the time when the transmission of the reference message is substantially started by means of the built-in timer (step S11).

[0053] Next, the microcomputer 31 determines whether the elapsed time has reached a certain time T1 (step S12). This certain time T1 corresponds to the first period T1 shown in FIG. 4. The first period T1 is, for example, 8 ms.

[0054] When it is determined in step S12 that a certain time T1 has been reached, the CAN controller 34 cancels the message box 341 (step S13). That is, the message in the message box 341 is cleared.

[0055] Next, the microcomputer 31 clears the count of the elapsed time started in step S11 (step S14) and ends a series of processes. The control device 30 repeatedly executes the above processes while the power is on.

[0056] As shown in FIG. 4, the control device 30 transmits a reference message every first period T1. The first period T1 is set to a length that can transmit all the messages that need to be periodically transmitted in the load drive system 14. Specifically, the control device 30 and the drive device 40 can each transmit all the first periodic messages once, and the control device 30 can transmit the second periodic messages a predetermined number of times. The predetermined number of times is determined by T1 / T2.

[0057] Next, with reference to FIG. 6, the processing performed by the device that has received the reference message will be described. In the present embodiment, the control device 30 and the drive device 40 execute the processing shown in FIG. 6.

[0058] First, the CAN controllers 34 and 45 receive a reference message from the communication bus 20 via the corresponding CAN transceivers 32 and 44 (step S20).

[0059] Next, the CAN controllers 34 and 45 cancel the message boxes 341 and 451 for transmission in preparation for the transmission of new periodic data messages (step S21).

[0060] Next, the CAN controllers 34 and 45 store the first periodic message to be transmitted according to the reference message in the message boxes 341 and 451 (step S22). The CAN controller 34 stores, as the first periodic message, the message of the target current value calculated by the CPU 33 in the message box 341. This message of the target current value corresponds to the first instruction message.

[0061] The CAN controller 45 stores, as the first periodic message, the message of the actual current value in the message box 451. The CAN controller 45 stores, as the first periodic message, the message of the detection value acquired from the sensor detection circuit 43 in the message box 451.

[0062] These first periodic messages have a lower priority of the ID code than the reference message. In the present embodiment, the first periodic message transmitted by the control device 30 has a higher priority of the ID code than the first periodic message transmitted by the drive device 40.

[0063] The control device 30 and the drive device 40 execute the above processing each time a reference message is received.

[0064] Next, based on FIG. 7, the processing that the control device 30 periodically performs regardless of the reference message will be described.

[0065] First, the CAN controller 34 of the control device 30 stores, as the second periodic message, the message of the duty ratio calculated by the CPU 33 in the message box 341 (step S30). The second periodic message corresponds to the second instruction message.

[0066] Next, the microcomputer 31 starts counting the elapsed time from the time when the second periodic message is set in the message box 341 (step S31).

[0067] Next, the microcomputer 31 determines whether the elapsed time has reached a fixed time T2 (step S32). This fixed time T2 corresponds to the second cycle T2 shown in FIG. 4. The second cycle T2 is shorter than the first cycle T1. The second cycle T2 is, for example, 2 ms. Therefore, the first cycle T1 is four times the second cycle T2.

[0068] If it is determined in step S32 that the fixed time T2 has been reached, the microcomputer 31 clears the count of the elapsed time started in step S31 (step S33) and ends the series of processes. The control device 30 repeatedly executes the above processes while the power is on.

[0069] As shown in FIG. 4, the control device 30 transmits a second periodic message every second cycle T2. The second periodic message has a higher priority of the ID code than the reference message and the first periodic message. The second periodic message with a shorter transmission cycle can be transmitted preferentially over the first periodic message with a longer transmission cycle.

[0070] Next, based on FIG. 8, it is a flowchart showing the processes executed by the control device 30 in response to the occurrence of a predetermined event.

[0071] First, the microcomputer 31 of the control device 30 determines whether an event corresponding to a predetermined event has occurred (step S40). As described above, the microcomputer 31 determines whether an abnormality has occurred based on the state of the automatic transmission 10. The microcomputer 31 determines whether an abnormality has occurred in the automatic transmission 10 based on the first periodic message transmitted by the drive device 40. The first periodic message transmitted by the drive device 40 is a message indicating the state of the automatic transmission 10 and corresponds to a status message. The process of step S40 executed by the microcomputer 31 corresponds to a determination unit.

[0072] When it is determined in step S40 that an event has occurred, the CAN controller 34 stores, in the message box 341, an aperiodic message to be transmitted according to the event (step S41), and terminates a series of processes. The control device 30 repeatedly executes the above processes while the power is on.

[0073] The aperiodic message is an emergency instruction message for putting the energization of all the solenoids 13 into a predetermined abnormal treatment state. The aperiodic message corresponds to an abnormality processing message. The aperiodic message has a higher ID code priority than the reference message, the first periodic message, and the second periodic message. Thereby, when an event occurs, the aperiodic message can be transmitted with priority over the transmission of other messages. The aperiodic message may be referred to as an event-driven transmission message.

[0074] Although an example of the aperiodic message for turning off the power supply switch 15 in order to put the energization of all the solenoids 13 into an abnormal treatment state has been shown, the present invention is not limited thereto. The aperiodic message may be a message for turning off all the drive switches 4111 in order to put the energization of all the solenoids 13 into an abnormal treatment state. The aperiodic message may be an instruction message for a power-on pattern fixed to a predetermined gear position (for example, the third gear) in order to put the energization of all the solenoids 13 into an abnormal treatment state.

[0075] Next, with reference to FIG. 9, the transmission and reception processing of messages executed by the control device 30 and the drive device 40 will be described.

[0076] First, the CAN controllers 34 and 45 determine whether there is a message stored in the corresponding message boxes 341 and 451 for transmission (step S50).

[0077] If it is determined in step S50 that there is a message, then the CAN controllers 34 and 45 next transmit the ID code associated with the stored message, that is, the priority information, to the communication bus 20 (step S51).

[0078] Next, the CAN controllers 34 and 45 determine whether the transmitted ID code has won arbitration (step S52).

[0079] If it is determined in step S52 that arbitration has been won, then the CAN controllers 34 and 45 next transmit the message for which arbitration has been won (step S53). When the transmission of the message is completed (step S54), the CAN controllers 34 and 45 wait for a predetermined time, for example, a time corresponding to 3 bits (step S55), and end the series of processes.

[0080] On the other hand, if it is determined in step S50 that there is no message, or if it is determined in step S52 that arbitration has been lost, the CAN controllers 34 and 45 wait for the reception of a message (step S56). When the reception of the message is completed (step S57), after executing the process of step S55, the series of processes is ended.

[0081] The control device 30 and the drive device 40 repeatedly execute the above process while the power is on. The control device 30 and the drive device 40 can execute transmission, reception, and arbitration control according to the CAN protocol by the process shown in FIG. 9.

[0082] <Summary of the First Embodiment> In the load drive system 14 of the present embodiment, the control device 30 transmits two types of instruction messages instructing the drive state of the solenoid 13 to the communication bus 20 with different transmission periods.

[0083] The control device 30 transmits a first periodic message instructing a target current value at a first period T1 (8 ms). The drive device 40 drives the solenoid 13 according to the target current value of the received first periodic message. The drive device 40 sets the duty ratio so that the actual current value follows the target current value, and outputs a PWM signal.

[0084] The control device 30 transmits a second periodic message instructing the duty ratio at a second period T2 (2 ms). The drive device 40 drives the solenoid 13 according to the duty ratio of the received second periodic message. The control device 30 instructs the duty ratio at a period shorter than the first period T1. The control device 30 including the microcomputer 31 finely changes (fine-tunes) the setting of driving the solenoid 13 according to the state of the automatic transmission 10. Thereby, even if current fluctuations such as overshoot and current ripple occur due to driving based on the target current value, this current fluctuation can be suppressed.

[0085] In a configuration that transmits messages at a fixed period, in order to reflect all the instruction contents, all the instruction messages must be transmitted in accordance with the earliest transmission period. In this case, the communication volume increases. Further, since the number of messages with an early transmission period increases, the noise increases. On the other hand, the control device 30 of the present embodiment does not transmit all the instruction messages in accordance with the earliest transmission period, but transmits each of the instruction messages at the timing required for control. Therefore, the communication volume between the control device 30 and the drive device 40 can be reduced.

[0086] In particular, the load drive system 14 of the present embodiment controls the driving of a plurality of solenoids 13 in the automatic transmission 10. In order to control the driving of a plurality of loads, the communication volume between the control device 30 and the drive device 40 is large. However, since each of the instruction messages is transmitted at the timing required for control, the communication volume can be reduced.

[0087] The communication method is not particularly limited as long as the control device 30 can transmit two types of instruction messages with different transmission periods to the drive device 40 via the communication bus 20. For example, a time-triggered method such as TTCAN or FlexRay (registered trademark) can also be adopted. Additionally, Ethernet (registered trademark) may be adopted. In the present embodiment, the control device 30 and the drive device 40 are configured to be able to transmit and receive messages via the in-vehicle network communication bus 20 compliant with the CAN protocol.

[0088] In the present embodiment, the PWM output circuit 413 of the drive circuit 41 generates PWM signals of a plurality of solenoid drive circuits 411 (drive switches 4111) according to the instruction of a single message transmitted from the control device 30. The PWM output circuit 413 converts the data of a single instruction message (frame) into a plurality of drive instructions without using a microcomputer. Since a plurality of solenoids 13 can be driven by a single instruction message, the communication volume can be reduced. Note that a single message transmitted by the control device 30 may include drive instructions for all the solenoids 13. The drive instructions for all the solenoids 13 may be divided into fewer messages than the number of solenoids 13.

[0089] In the present embodiment, the microcomputer 31 of the control device 30 determines whether an abnormality has occurred in the automatic transmission 10 based on the state of the automatic transmission 10 acquired from the drive device 40. When it is determined that an abnormality has occurred, the CAN controller 34 of the control device 30 transmits an aperiodic message instructing processing corresponding to the abnormality to the drive device 40 via the communication bus 20. The aperiodic message corresponds to an abnormality processing message.

[0090] The aperiodic message has a higher priority of the ID code than the first periodic message and the second periodic message which are instruction messages. Thereby, the aperiodic message can be transmitted according to the timing of the occurrence of an abnormality (event) without being transmitted at the transmission period of the periodic message, that is, at a determined timing.

[0091] In particular, in this embodiment, as an irregular message, an emergency instruction message for setting energization to all solenoids 13 to a predetermined abnormal treatment state is transmitted. The drive device 40 executes abnormal processing such as turning off the power supply switch 15 in accordance with the received irregular message. The drive device 40 does not execute the operation of the microcomputer (CPU). The drive device 40 can execute the abnormal treatment speedily because the time required for the operation process can be eliminated.

[0092] The control device 30 and the object for transmitting the state of the automatic transmission 10 to the control device 30 may be directly connected by a communication line, a so-called JICA line. For example, the control device 30 and the sensor 16 may be directly connected by a JICA line. The control device 30 and the drive device 40 may be directly connected by a JICA line. In such a configuration, a signal indicating the state of the automatic transmission 10 is transmitted to the control device 30 through the JICA line.

[0093] In this embodiment, the CAN controller 45 of the drive device 40 transmits a first periodic message indicating the state of the automatic transmission 10 to the control device 30 via the communication bus 20 (CAN bus). Thereby, compared with the configuration using a JICA line, the noise immunity can be improved and the communication reliability can be enhanced. Also, since bidirectional communication becomes possible, the JICA line for acquiring the state of the automatic transmission 10 can be eliminated. Therefore, the number of communication lines (wiring) can be reduced.

[0094] The arrangement of the control device 30 and the drive device 40 that constitute the load drive system 14 is not particularly limited. In the present embodiment, the drive device 40 is arranged on the valve body 11 that constitutes the automatic transmission 10. That is, the drive device 40 forms an electromechanical integrated device together with the automatic transmission 10. On the other hand, the control device 30 is mechanically separated from the automatic transmission 10. In this way, the control device 30 including the microcomputer 31 is kept away from the heat and vibration of the automatic transmission 10 (load). Thereby, the costs for heat countermeasures and vibration countermeasures for the control device 30 can be reduced. Further, the drive device 40 does not include a microcomputer and does not malfunction variously due to calculation. Therefore, the drive device 40 can dispense with an operation monitoring circuit. Thereby, the costs for heat countermeasures and vibration countermeasures can be reduced.

[0095] (Second Embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be incorporated. In the preceding embodiment, messages were sequentially stored in the message box. Instead of this, message boxes may be individually provided according to the ID code.

[0096] FIG. 10 shows a schematic configuration of the drive device 40 in the load drive system 14 of the present embodiment. In FIG. 10, some elements of the drive circuit 41 are omitted. Although not shown, in the present embodiment, the automatic transmission 10 has three solenoids 13. Therefore, as shown in FIG. 10, the solenoid drive circuit 411 has three drive switches 4111. In FIG. 10, each drive switch 4111 is denoted as Dr1, Dr2, and Dr3. Also, in the sensor detection circuit 43, the detection units of the respective sensors 16 are denoted as sensor 1, sensor 2, and sensor 3.

[0097] As shown in FIG. 10, the CAN controller 45 of the drive device 40 has message boxes 451 and 452 according to ID codes (priority information). The message box 451 for transmission is divided for each ID code. Therefore, the information to be transmitted is determined for each message box 451. The CAN controller 45 stores, for example, the data transmitted from the sensor detection circuit 43 in the message box 451 with the ID corresponding to the data.

[0098] In the example of FIG. 10, the CAN controller 45 stores the output of sensor 1 in the message box 451 with ID4. The outputs of sensor 2 and sensor 3 are combined. The CAN controller 45 stores the combined data in the message box 451 with ID5. The CAN controller 45 executes transmission processing according to the priorities of ID4 and ID5. In this way, the data of sensors 2 and 3 are transmitted to the control device 30 as a single message (frame).

[0099] The message box 452 for reception is divided for each ID code. Therefore, the information to be received is determined for each message box 452. The CAN controller 45 stores, for example, the data transmitted from the sensor detection circuit 43 in the message box 451 with the ID corresponding to the data.

[0100] In the example of FIG. 10, the data instructing the driving of Dr1 and Dr2 among the driving switches 4111 of the solenoid driving circuit 411 is stored in the message box 452 with ID1. The CAN controller 45 outputs the data stored in the message box 451 with ID1 to Dr1 and Dr2. The data of ID1 is input to a PWM output circuit 413 (not shown) after being divided. Thereby, the PWM output circuit 413 generates PWM signals corresponding to Dr1 and Dr2 respectively and outputs them to the gates of Dr1 and Dr2. In this way, the data of a single message (frame) is converted into drive instructions for a plurality of Dr1 and Dr2 without using a microcomputer.

[0101] In the message box 452 of ID2, data for instructing the drive of Dr3 among the drive switches 4111 of the solenoid drive circuit 411 is stored. The CAN controller 45 outputs the data stored in the message box 451 of ID2 to Dr3. The PWM output circuit 413 generates a PWM signal corresponding to Dr3 based on the data of ID2 and outputs it to the gate of Dr3.

[0102] In the message box 452 of ID3, an aperiodic message is stored. When the data of the aperiodic message is, for example, data for instructing the turn-off of the power supply switch 15, the CAN controller 45 outputs the emergency instruction data stored in the message box 451 of ID3 to the cutoff circuit 42. As a result, the cutoff circuit 42 turns off the power supply switch 15. For configurations other than the above, they are the same as the configurations described in the previous embodiment.

[0103] <Summary of the Second Embodiment> According to the present embodiment, the CAN controller 45 of the drive device 40 includes message boxes 451 and 452 corresponding to the ID code, and executes input / output processing corresponding to the message boxes 451 and 452. Thereby, overwriting of incorrect messages (data) can be prevented. Also, in the drive device 40, a plurality of processes with different ID codes can be executed in parallel.

[0104] Furthermore, by adopting independent message boxes 451 and 452 for each control group, it is possible to suppress the influence on other control systems in the event of a failure. For example, a control group is set for each solenoid 13. The control group is set according to the process executed by the microcomputer 31.

[0105] Note that, also for the control device 30, the message boxes 341 and 342 of the CAN controller 34 may be separated according to the ID code.

[0106] The division and combination of data are not particularly limited to the above-described examples. The number of message boxes 451 and 452 is also not particularly limited to the above-described examples. It suffices to have a number corresponding to the ID code.

[0107] (Other embodiments) The disclosure in this specification, drawings, etc. is not limited to the illustrated embodiments. The disclosure includes the illustrated embodiments and modifications by those skilled in the art based thereon. For example, the disclosure is not limited to the combination of parts and / or elements shown in the embodiments. The disclosure can be implemented by various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes those in which parts and / or elements of the embodiments are omitted. The disclosure includes the replacement or combination of parts and / or elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. Some of the disclosed technical scopes should be understood to be indicated by the description of the claims and to include all modifications within the meaning and scope equivalent to the description of the claims.

[0108] The disclosure in the specification, drawings, etc. is not limited by the description of the claims. The disclosure in the specification, drawings, etc. includes the technical idea described in the claims and extends to more diverse and extensive technical ideas than the technical idea described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification, drawings, etc. without being restricted by the description of the claims.

[0109] In the drive device 40, although the configuration in which the cutoff circuit 42 is provided separately from the drive circuit 41 is shown, it is not limited thereto. The cutoff circuit 42 may be configured as a part of the drive circuit 41.

[0110] For example, it may be configured not to include the cutoff circuit 42 and the power supply switch 15.

[0111] The number of the solenoid 13 as the load is not particularly limited. The load is not limited to the automatic transmission 10 (solenoid 13). The load is not limited to those mounted on the vehicle. The above-described load driving system 14 is suitable for controlling the driving states of a plurality of actuators.

Explanation of Signs

[0112] 10…Automatic transmission, 11…Valve body, 12…Solenoid valve, 13…Solenoid, 14…Load driving system, 15…Power supply switch, 16…Sensor, 161…Hydraulic pressure sensor, 162…Rotation sensor, 163…Oil temperature sensor, 20…Communication bus, 30…Control device, 31, 35…Microcomputer, 32…CAN transceiver, 33…CPU, 34…CAN controller, 341, 342…Message box, 40…Driving device, 41…Driving circuit, 411…Solenoid driving circuit, 411…Driving switch, 412…Current detection circuit, 4121…Resistor, 4122…Operational amplifier, 4123…A / D converter, 413…PWM output circuit, 42…Cut-off circuit, 43…Sensor detection circuit, 44…CAN transceiver, 45…CAN controller, 451, 452…Message box

Claims

1. A communication bus (20), A control-side communication unit (32, 34) that transmits an instruction message indicating the driving state of a load (10) via the communication bus, wherein the control-side communication unit transmits a first instruction message in a first cycle and a second instruction message in a second cycle different from the first cycle as the instruction message, and a control device (30); A drive-side communication unit (44, 45) that receives the instruction message via the communication bus, and a drive circuit (41) that drives the load according to the received instruction message, and a drive device (40); The control device includes a microcomputer. The drive device does not include a microcomputer, receives the instruction message indicating the calculation result of the microcomputer included in the control device via the communication bus, and drives the load according to the calculation result. The control device has a determination unit (S40) that determines whether an abnormality has occurred in the load based on the state of the load acquired from the outside. The control-side communication unit transmits the instruction message according to a pre-associated priority order. When the determination unit determines that an abnormality has occurred, the control-side communication unit transmits an abnormality processing message having a higher priority than the instruction message to the drive device via the communication bus. A load drive system.

2. The drive device has a plurality of drive units (411) for individually driving a plurality of the loads. The plurality of drive units operate according to an instruction of a single instruction message transmitted from the control device. The load drive system according to claim 1.

3. When the drive-side communication unit receives the abnormality processing message, the drive device sets the energization to the load in an abnormal treatment state according to the abnormality processing message. The load drive system according to claim 1 or claim 2.

4. The drive-side communication unit transmits a state message indicating the state of the load to the control device via the communication bus. The control-side communication unit receives the state message via the communication bus. The load drive system according to any one of claims 1 to 3.

5. The drive-side communication unit has message boxes (451, 452) divided according to a pre-associated priority order. The load drive system according to any one of claims 1 to 4.

6. The drive device forms an electromechanical integrated device together with the load, The control device is separated from the electromechanical integrated device. The load drive system according to any one of claims 1 to 5.

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