Load Drive 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 herein relates to a load driving system. [Background technology]

[0002] Patent Document 1 discloses a load drive system including a control device and a drive device. The contents of the prior art document are incorporated by reference as explanations of technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-24080 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the drive device has a decoder to which a drive instruction for the load is input from a control device, and a drive circuit that drives the load according to the signal converted by the decoder. In such a configuration, the control device transmits a drive instruction at a constant cycle. Therefore, if multiple drive instructions are to be transmitted, there is a risk that the amount of communication will increase. In the above-mentioned respects, or in other respects not mentioned, further improvements are required in the load drive system.

[0005] One disclosed object is to provide a load driving system capable of reducing the amount of communication. [Means for solving the problem]

[0006] The load drive system disclosed herein comprises: A communication bus (20); a control device (30) having a control side communication unit (32, 34) that transmits an instruction message instructing a drive state of a load (10) via a communication bus, the control side communication unit transmitting, as the instruction messages, a first instruction message in a first period and a second instruction message in a second period different from the first period; 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 in accordance with the received instruction message; The control device includes a microcomputer. The drive-side communication unit receives an instruction message indicating a calculation result of the microcomputer included in the control device via the communication bus, The drive circuit drives the load according to the output of the drive-side communication unit. death, The control device has 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 an external source; The control 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, which has a higher priority than an instruction message, to the drive device via the communication bus.

[0007] In the disclosed load driving system, the control device transmits a first instruction message in a first period, which causes the driving device to drive the load according to the first instruction message. The control device transmits a second instruction message in a second period different from the first period, which causes the driving device to drive the load according to the second instruction message. The control device does not transmit all instruction messages in, for example, the shortest transmission period, but transmits each instruction message at a timing required for control. As a result, a load driving system capable of reducing communication volume can be provided.

[0008] The various aspects disclosed in this specification adopt different technical means to achieve their respective objectives. The claims and the parenthetical symbols described in this section are merely illustrative of the corresponding relationship with the embodiments described below, and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer with reference to the following detailed description and the accompanying drawings. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing a schematic configuration of an automatic transmission to which a load drive system according to a first embodiment is applied. [Diagram 2] FIG. 1 illustrates a load driving system. [Diagram 3] FIG. 2 is a diagram showing a schematic configuration of a drive circuit. [Figure 4] 4 is a timing chart showing the relationship between various messages transmitted over time in the load driving system. [Diagram 5] 13 is a flowchart showing a reference message transmission process executed by a control device. [Figure 6] 6 is a flowchart showing a first periodic message transmission process executed by a control device and a driving device. [Figure 7] 13 is a flowchart showing a second periodic message transmission process executed by the control device. [Figure 8] 4 is a flowchart showing a process executed by a control device in response to the occurrence of a predetermined event. [Figure 9] 5 is a flowchart showing a message transmission / reception process executed by a control device and a drive device. [Figure 10] FIG. 11 is a diagram showing a configuration of a drive device in a load drive system according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, several embodiments will be described with reference to the drawings. In addition, by assigning the same reference numerals to corresponding components in each embodiment, duplicated explanations may be omitted. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other parts of the configuration. In addition to the combination of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0011] (First embodiment) The load drive system according to the present embodiment can be applied to a load mounted on a vehicle, for example. In the following, an example in which the load drive system is applied to an automatic transmission of a vehicle will be described.

[0012] <Automatic transmission> First, the schematic configuration of an automatic transmission will be described with reference to Fig. 1. Fig. 1 shows an automatic transmission to which a load drive system according to this embodiment is applied. In Fig. 1, the automatic transmission is indicated as T / M and the valve body is indicated as V / B.

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

[0014] A hydraulic circuit that adjusts the pressure of hydraulic oil supplied to the transmission mechanism is formed inside the valve body 11. The valve body 11 has a plurality of solenoid valves 12 that adjust the pressure of hydraulic oil pumped from an oil pump and supply it to the friction elements. For convenience, only one solenoid valve 12 is shown in FIG. 1. The solenoid valve 12 has a solenoid 13. The solenoid 13 is sometimes called a coil. The hydraulic oil is adjusted by controlling the supply of electricity to the solenoid 13.

[0015] <Load drive system> Next, a schematic configuration of the load drive system will be described with reference to Figs. 1, 2, and 3. Fig. 2 is a diagram showing the load drive system. For convenience, the illustration of a monitoring microcomputer is omitted in Fig. 2. Also, the current 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 a drive circuit of the drive device. For convenience, only the solenoid drive circuit and current detection circuit corresponding to one solenoid 13 are shown in Fig. 3 out of the solenoid drive circuits and current detection circuits.

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

[0017] As shown in Fig. 1 and Fig. 2, the load drive system 14 includes at least a communication bus 20, a control device 30, and a drive device 40. The load drive system 14 controls the drive of a load. The load to be controlled is an automatic transmission 10 including a solenoid 13 and a valve body 11. In the load drive system 14, the drive device 40 is disposed on the valve body 11. In other words, the drive device 40 and the automatic transmission 10 have a mechanically and electrically integrated structure. 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) other than the control device 30 and the drive device 40 may be connected to the communication bus 20. In this 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 that complies with the CAN protocol. The communication bus is sometimes referred to as a CAN bus. CAN is an abbreviation for Controller Area Network. CAN is a registered trademark.

[0019] In the load driving system 14 of this embodiment, messages transmitted by the control device 30 and the driving device 40 are assigned a predetermined priority according to the importance and type of the message. When each message is transmitted, priority information (ID code) indicating the priority of the message is transmitted first. If there is a conflict between the transmission of priority information for multiple messages, arbitration is performed between the priority information, and the priority information with the higher priority acquires the right to transmit.

[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, and a ROM, RAM, registers, etc. (not shown). In the microcomputer 31, the CPU 33 executes various controls according to a control program pre-stored in the ROM while utilizing the temporary storage functions of the RAM and registers. The CPU 33 executes controls using data acquired from outside the control device 30, such as a detection signal from a sensor. The CPU 33 in this embodiment executes controls of the solenoid 13 and, ultimately, 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 a current value to be passed through the solenoid 13 to bring the solenoid 13 into a target state. The microcomputer 31 acquires the state of the automatic transmission 10 and calculates a target hydraulic pressure, which is a required value for the output hydraulic pressure of the solenoid 13. The microcomputer 31 calculates the target hydraulic pressure based on, for example, the input side rotation speed and the output side rotation speed of the automatic transmission 10. The microcomputer 31 sets a target current value based on the calculated target hydraulic pressure. The relationship between the target hydraulic pressure and the target current value is determined in advance, 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 ripples at the beginning of shifting. The duty ratio is the duty ratio of a PWM signal output to a gate of a drive switch 4111, which will be described later. The microcomputer 31 sets the duty ratio based on at least one of the pressure of hydraulic oil in the hydraulic circuit, the temperature of hydraulic oil, and the actual current value flowing through the solenoid 13, for example. The control device 30 indicates the duty ratio to the drive device 40. The control device 30 may indicate the duty ratio during a period when the power of the control device 30 is turned on, or may indicate the duty ratio only during a temporary period such as the beginning of shifting.

[0023] The CPU 33 of the microcomputer 31 judges whether or not an abnormality has occurred based on the state of the automatic transmission 10. The microcomputer 31, for example, compares the pressure of the hydraulic oil with a hydraulic pressure threshold value to judge whether or not an abnormality has occurred. The microcomputer 31, for example, compares the temperature of the hydraulic oil with a temperature threshold value to judge whether or not an abnormality has occurred. If it is judged that an abnormality has occurred, the control device 30 outputs an emergency instruction to the drive device 40 to set the energization of all solenoids 13 to a predetermined abnormality treatment state. The control device 30 of this embodiment outputs an emergency cutoff instruction to the drive device 40 as an emergency instruction to cut off the energization of all solenoids 13.

[0024] The microcomputer 31 has a built-in CAN controller 34 for transmitting and receiving messages via the communication bus 20. The CAN controller 34 executes communication control in accordance with 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 to the communication bus 20. The CAN transceiver 32 converts electrical characteristics between the communication bus 20 and the CAN controller 34, thereby enabling communication messages to be transmitted in both directions between the communication bus 20 and the CAN controller 34. For example, the CAN transceiver 32 converts bus-level signals of the communication bus 20 into digital signals that the CAN controller 34 can handle, thereby enabling it to recognize dominants and recessives. In other words, the CAN controller 34 is connected to the communication bus 20 via the CAN transceiver 32, thereby enabling it to transmit and receive communication messages to and from the communication bus 20.

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

[0027] The CAN controller 34 receives frames from the communication bus 20 via the CAN transceiver 32, extracts messages, etc., and stores them sequentially in a message box 342. The CAN controller 34 outputs the received messages to the transmission target according to the priority order of the ID code. The CAN controller 34 arbitrates the transmission right when frames collide on the communication bus 20 (bit-by-bit non-destructive arbitration). The CAN controller 34 also detects and notifies errors that occur in relation 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 may be called a main microcomputer, and the microcomputer 35 may be called a monitoring microcomputer. The microcomputer 35 monitors, for example, whether there is a watchdog abnormality, a communication abnormality, or an abnormality in the calculation function of the microcomputer 31. In addition to the above-mentioned monitoring function, the microcomputer 35 may have a function of assisting the control executed by the microcomputer 31. The microcomputer 35 may execute a control different from that of the load driving system 14. The microcomputer 35 may also have a built-in CAN controller (not shown) and be configured to be able to send and receive 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 monitor each other to see if they are operating normally. The monitoring means of the microcomputer 31 is not limited to the microcomputer 35. A monitoring IC may be provided instead of the microcomputer 35. The control device 30 may be configured without including a 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 shutoff circuit 42, a sensor detection circuit 43, a CAN transceiver 44, and a CAN controller 45. The drive circuit 41 drives the solenoid 13 in accordance with an instruction from the control device 30. As shown in Figs. 2 and 3, the drive circuit 41 includes 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 driving circuit 411 has a driving switch 4111 connected in series to the corresponding solenoid 13. The driving switch 4111 is provided individually for each solenoid 13. The driving switch 4111 is provided on the current path of the corresponding solenoid 13. The driving switch 4111 repeatedly turns on and off in response to a PWM signal output from a PWM output circuit 413, and connects or disconnects the solenoid 13 and the power source. The solenoid driving circuit 411 has a plurality of driving switches 4111 to control the current supply to the plurality of solenoids 13. The solenoid driving circuit 411 corresponds to a driving unit that drives the load 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 this embodiment is provided on the power supply side with respect to the solenoid 13. In this embodiment, a MOSFET is used 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 each solenoid 13.

[0034] The resistor 4121 is connected in series to the corresponding solenoid 13. The resistor 4121 in this embodiment is provided on the ground side of the solenoid 13. One end of the resistor 4121 is connected to the downstream terminal of the solenoid 13, and the other end is grounded. In this manner, the resistor 4121 is provided so that the voltage generated across both ends corresponds 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 the output of the operational amplifier 4122, that is, the actual current value, and outputs the converted value.

[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 the multiple drive switches 4111 according to a single instruction message transmitted from the control device 30. The PWM output circuit 413 has a circuit that executes feedback control and a circuit that sets a duty ratio 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.

[0038] The feedback control circuit has a circuit for calculating the deviation (current deviation) between the target current value and the actual current value, and a circuit for calculating a 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 for calculating a duty ratio proportional to the deviation, a circuit for calculating a duty ratio proportional to an integral value of the deviation, a circuit for calculating a duty ratio proportional to a differential value of the deviation, and a circuit for calculating 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 receives an instruction for the duty ratio from the control device 30 via the communication bus 20, it sets the obtained duty ratio in the register. The duty ratio setting circuit generates a PWM signal of the duty ratio set in the register at a predetermined drive 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 current path of the solenoid 13. A single (common) power supply switch 15 is provided for the multiple solenoids 13. The power supply switch 15 controls the current supply 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 on either the power supply side or the ground side of the solenoid 13. In this embodiment, the power supply switch 15 is disposed on the power supply side. The power supply switch 15 is provided on the power supply side (upstream side) of the connection point of each solenoid 13.

[0042] The cutoff circuit 42 drives the power supply switch 15 in accordance with an 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. In this embodiment, 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 being input.

[0043] The sensor detection circuit 43 detects a signal from the sensor 16. The sensor detection circuit 43 performs predetermined processing, such as waveform detection and A / D conversion, on the input signal from the sensor 16. The sensor 16 detects the load state, i.e., the state of the automatic transmission 10 including the valve body 11. The sensor 16 in this embodiment has an oil pressure sensor 161, a rotation sensor 162, and an oil temperature sensor 163. The oil pressure sensor 161 detects the pressure of the hydraulic oil in the hydraulic circuit. The rotation sensor 162 detects the rotation speed of the automatic transmission 10. The rotation sensor 162 includes, for example, a sensor that detects the rotation speed on the input side of the automatic transmission 10 and a sensor that detects the rotation 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 also to the communication bus 20. The CAN transceiver 44 converts electrical characteristics between the communication bus 20 and the CAN controller 45, thereby enabling communication messages to be transmitted in both directions between the communication bus 20 and the CAN controller 45. The CAN controller 45 is connected to the communication bus 20 via the CAN transceiver 44, thereby enabling transmission and reception of communication messages between the communication bus 20 and the CAN controller 45.

[0045] The CAN controller 45 has a message box for storing messages. The CAN controller 45 has a message box 451 for transmission and a message box 452 for reception. The CAN controller 45 sequentially stores messages for transmission acquired via the communication interface in the message box 451. The CAN controller 45 transmits the stored messages according to the priority of the ID code. 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 frames from the communication bus 20 via the CAN transceiver 44, extracts messages, etc., and stores them sequentially in a message box 452. The CAN controller 45 outputs the received messages to the transmission target according to the priority order of the ID code. 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 that occur in relation 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 and the drive circuit 41, the interruption circuit 42, and the sensor detection circuit 43. SPI is an abbreviation for Serial Peripheral Interface.

[0048] The load driving system 14 may further include at least one of the above-mentioned power supply switch 15 and the sensor 16. For example, the load driving system 14 may include both the power supply switch 15 and the sensor 16. The load driving system 14 may not include the power supply switch 15 and the sensor 16, and the power supply switch 15 and the sensor 16 may be disposed outside the load driving system 14.

[0049] <Load drive system operation> Next, the operation of the load driving system 14 will be described with reference to Figs. 4 to 9. 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 reference message transmission process executed by the control device 30. Fig. 6 is a flowchart showing the first regular message transmission process executed by the control device 30 and the driving device 40. Fig. 7 is a flowchart showing the second regular message transmission process 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 message transmission and reception process executed by the control device 30 and the driving device 40. In Figs. 5 to 9, the message box is indicated as MB.

[0050] First, the reference message transmission process executed by the control device 30 will be described with reference to FIGS.

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

[0052] Next, the microcomputer 31 starts counting the time that has elapsed since the transmission of the reference message was actually started, using the built-in timer (step S11).

[0053] Next, the microcomputer 31 determines whether the elapsed time reaches 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] If it is determined in step S12 that the 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 that started in step S11 (step S14), and ends the 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 allows all messages that need to be transmitted periodically in the load driving system 14 to be transmitted. Specifically, the first period T1 is set to a length that allows the control device 30 and the driving device 40 to transmit all first periodic messages once each, and allows the control device 30 to transmit the second periodic message a predetermined number of times. The predetermined number of times is determined by T1 / T2.

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

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

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

[0060] Next, the CAN controllers 34, 45 store a first periodic message to be transmitted in response to the reference message in the message boxes 341, 451 (step S22). The CAN controller 34 stores a message of the target current value calculated by the CPU 33 as the first periodic message 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, a message of the actual current value in the message box 451. The CAN controller 45 stores, as the first periodic message, a message of the detection value acquired from the sensor detection circuit 43 in the message box 451.

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

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

[0064] Next, a process that the control device 30 periodically performs, regardless of the reference message, will be described with reference to FIG.

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

[0066] Next, the microcomputer 31 starts counting the time that has elapsed since the second periodic message was set in the message box 341 (step S31).

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

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

[0069] As shown in Fig. 4, the control device 30 transmits a second regular message at every second period T2. The second regular message has a higher priority of ID code than the reference message and the first regular message. The second regular message with a shorter transmission period can be transmitted in preference to the first regular message with a longer transmission period.

[0070] Next, FIG. 8 is a flowchart showing a process 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 phenomenon 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 regular message transmitted by the drive unit 40. The first regular message transmitted by the drive unit 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 the non-periodic message to be transmitted in response to the event in the message box 341 (step S41), and ends the series of processes. The control device 30 repeatedly executes the above processes while the power is on.

[0073] The non-periodic message is an emergency instruction message for setting the power supply to all solenoids 13 to a specified abnormality handling state. The non-periodic message corresponds to an abnormality handling message. The non-periodic message has a higher ID code priority than the reference message, the first periodic message, and the second periodic message. This allows the non-periodic message to be transmitted in priority over other messages when an event occurs. The non-periodic message is sometimes referred to as an event transmission message.

[0074] Although an example of the non-periodic message is a message for turning off the power supply switch 15 in order to put the power supply to all solenoids 13 into an abnormality handling state, the non-periodic message is not limited to this. The non-periodic message may be a message for turning off all drive switches 4111 in order to put the power supply to all solenoids 13 into an abnormality handling state. The non-periodic message may be a message instructing an energization pattern for fixing the power supply to a predetermined gear position (for example, third gear) in order to put the power supply to all solenoids 13 into an abnormality handling state.

[0075] Next, a message transmission / reception process executed by the control device 30 and the drive device 40 will be described with reference to FIG.

[0076] First, the CAN controllers 34, 45 determine whether or not there is a message stored in the corresponding transmission message box 341, 451 (step S50).

[0077] If it is determined in step S50 that a message is present, then the CAN controllers 34, 45 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, 45 determine whether or not the transmitted ID code has won the arbitration (step S52).

[0079] If it is determined in step S52 that the arbitration has been won, then the CAN controllers 34, 45 transmit the arbitration-winning message (step S53). When the message transmission is completed (step S54), the CAN controllers 34, 45 wait for a predetermined time, for example, a time for 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 to receive a message (step S56). When message reception is completed (step S57), the process of step S55 is executed, and then the series of processes is terminated.

[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.

[0082] <Summary of the First Embodiment> In the load driving system 14 of the present embodiment, the control device 30 transmits two types of instruction messages for instructing the driving state of the solenoid 13 to the communication bus 20 at 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 a 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 indicating 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 indicates the duty ratio at a period shorter than the first period T1. The control device 30, which includes a microcomputer 31, minutely changes (corrects) the drive setting of the solenoid 13 according to the state of the automatic transmission 10. As a result, even if current fluctuations such as overshoot and current ripple occur due to drive based on the target current value, the current fluctuations can be suppressed.

[0085] In a configuration in which messages are transmitted at a fixed period, in order to reflect all instruction contents, all instruction messages must be transmitted in accordance with the shortest transmission period. In this case, the amount of communication increases. Also, since the number of messages with short transmission periods increases, noise increases. In contrast, the control device 30 of this embodiment does not transmit all instruction messages in accordance with the shortest transmission period, but transmits each instruction message at the timing required for control. Therefore, the amount of communication between the control device 30 and the drive device 40 can be reduced.

[0086] In particular, the load drive system 14 of this embodiment controls the drive of multiple solenoids 13 in the automatic transmission 10. Since the drive of multiple loads is controlled, the amount of communication between the control device 30 and the drive device 40 is large. However, since each instruction message is transmitted at a timing required for control, the amount of communication 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 cycles to the drive device 40 via the communication bus 20. For example, a time trigger method such as TTCAN or FlexRay (registered trademark) can be adopted. Ethernet (registered trademark) may also be adopted. In this embodiment, the control device 30 and the drive device 40 are configured to be able to transmit and receive messages via the communication bus 20 of an in-vehicle network that complies with the CAN protocol.

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

[0089] In this embodiment, the microcomputer 31 of the control device 30 determines whether or not an abnormality has occurred in the automatic transmission 10 based on the state of the automatic transmission 10 acquired from the drive device 40. If it is determined that an abnormality has occurred, the CAN controller 34 of the control device 30 transmits a non-periodic message instructing a process corresponding to the abnormality to the drive device 40 via the communication bus 20. The non-periodic message corresponds to an abnormality process message.

[0090] Non-periodic messages have a higher priority in terms of ID code than the first and second periodic messages, which are instruction messages. This makes it possible to send non-periodic messages according to the timing of an abnormality (event) occurrence, rather than at the transmission cycle of periodic messages, i.e., at a set timing.

[0091] Particularly in this embodiment, an emergency instruction message for setting the power supply to all solenoids 13 to a predetermined abnormality handling state is transmitted as the non-periodic message. The driving device 40 executes abnormality handling, such as turning off the power supply switch 15, in accordance with the received non-periodic message. The driving device 40 does not execute calculations in a microcomputer (CPU). By eliminating the time required for calculation processing, the driving device 40 can quickly handle the abnormality.

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

[0093] In this embodiment, the CAN controller 45 of the drive unit 40 transmits a first periodic message indicating the state of the automatic transmission 10 to the control unit 30 via the communication bus 20 (CAN bus). This improves noise resistance and increases the reliability of communication compared to a configuration using direct wiring. In addition, since bidirectional communication is possible, the direct wiring 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 constituting the load drive system 14 is not particularly limited. In this embodiment, the drive device 40 is arranged on the valve body 11 constituting the automatic transmission 10. That is, the drive device 40 and the automatic transmission 10 form an electromechanical integrated device. 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). This makes it possible to reduce the cost of taking measures against heat and vibration for the control device 30. In addition, the drive device 40 does not include a microcomputer, and does not cause various malfunctions due to calculations. Therefore, the drive device 40 can eliminate the need for a calculation monitoring circuit. This makes it possible to reduce the cost of taking measures against heat and vibration.

[0095] Second embodiment This embodiment is a modified example based on the preceding embodiment, and the description of the preceding embodiment can be used. In the preceding embodiment, messages are stored in the message box in sequence. Instead of this, a message box may be provided separately according to the ID code.

[0096] FIG. 10 shows a schematic configuration of the drive device 40 in the load drive system 14 of this embodiment. In FIG. 10, some elements of the drive circuit 41 are omitted. Although not shown, in this 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, the drive switches 4111 are indicated as Dr1, Dr2, and Dr3. Also, in the sensor detection circuit 43, the detection units of the sensors 16 are indicated as sensor 1, sensor 2, and sensor 3.

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

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

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

[0100] In the example of FIG. 10, 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 of ID1. The CAN controller 45 outputs the data stored in the message box 451 of ID1 to Dr1 and Dr2. The data of ID1 is divided and then input to the PWM output circuit 413 (not shown). As a result, 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 driving instructions for a plurality of Dr1 and Dr2 without using a microcomputer.

[0101] Data instructing the driving of Dr3 among the driving switches 4111 of the solenoid driving circuit 411 is stored in the message box 452 of ID2. 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] An aperiodic message is stored in the message box 452 of ID3. If the data of the aperiodic message is, for example, data instructing to turn off 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. The configuration other than the above is the same as the configuration described in the preceding embodiment.

[0103] <Summary of the second embodiment> According to this embodiment, the CAN controller 45 of the drive device 40 is provided with message boxes 451, 452 corresponding to the ID codes, and executes input / output processing corresponding to the message boxes 451, 452. This makes it possible to prevent overwriting of erroneous messages (data). Also, in the drive device 40, it is possible to execute multiple processes with different ID codes in parallel.

[0104] Furthermore, by using independent message boxes 451, 452 for each control group, it is possible to prevent a failure from affecting other control systems. 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] Incidentally, in the control device 30 as well, the message boxes 341, 342 of the CAN controller 34 may be divided according to the ID code.

[0106] The division and joining of data is not particularly limited to the above example. The number of message boxes 451, 452 is also not particularly limited to the above example. It is sufficient to provide the number according to the ID code.

[0107] (Other embodiments) The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure includes the exemplified 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 the omission of parts and / or elements of the embodiments. The disclosure includes the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are indicated by the description of the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the description of the claims.

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

[0109] In the above embodiment, the cutoff circuit 42 is provided separately from the drive circuit 41 in the drive device 40. However, the present invention is not limited to this. The cutoff circuit 42 may be configured as a part of the drive circuit 41.

[0110] For example, the interrupter circuit 42 and the power supply switch 15 may be omitted.

[0111] The number of solenoids 13, which are the loads, is not particularly limited. The load is not limited to the automatic transmission 10 (solenoids 13). The load is not limited to a load mounted on a vehicle. The load drive system 14 described above is suitable for controlling the drive state of a plurality of actuators. [Explanation of symbols]

[0112] 10...automatic transmission, 11...valve body, 12...solenoid valve, 13...solenoid, 14...load drive system, 15...power supply switch, 16...sensor, 161...oil 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...drive device, 41...drive circuit, 411...solenoid drive circuit, 411...drive switch, 412...current detection circuit, 4121...resistor, 4122...operational amplifier, 4123...A / D converter, 413...PWM output circuit, 42...shutdown circuit, 43...sensor detection circuit, 44...CAN transceiver, 45...CAN controller, 451, 452...message box

Claims

1. A communication bus (20); a control device (30) having a control side communication unit (32, 34) that transmits an instruction message instructing a drive state of a load (10) via the communication bus, the control side communication unit transmitting, as the instruction message, a first instruction message in a first period and a second instruction message in a second period different from the first period; a driving device (40) including a driving side communication unit (44, 45) that receives the instruction message via the communication bus, and a driving circuit (41) that drives the load in accordance with the received instruction message; The control device includes a microcomputer. the driving-side communication unit receives the instruction message indicating a calculation result of the microcomputer included in the control device via the communication bus; the drive circuit drives the load in accordance with an output of the drive-side communication unit; The control device has a determination unit (S40) that determines whether or not an abnormality has occurred in the load based on a state of the load acquired from an external device, The control side communication unit transmits the instruction message in accordance with a pre-associated priority order; A load driving system in which, when the judgment 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 driving device via the communication bus.

2. The driving device has a plurality of driving units (411) for individually driving a plurality of the loads, 2. The load driving system according to claim 1, wherein the plurality of driving units operate in accordance with one of the instruction messages transmitted from the control device and including a plurality of driving instructions for the plurality of loads.

3. 3. The load driving system according to claim 1, wherein when the drive-side communication unit receives the abnormality processing message, the drive device brings the power supply to the load into an abnormality processing state in accordance with the abnormality processing message.

4. the drive-side communication unit transmits a status message indicating a status of the load to the control device via the communication bus; 4. The load driving system according to claim 1, wherein the control side communication section receives the status message via the communication bus.

5. 5. The load driving system according to claim 1, wherein the driving side communication section has message boxes (451, 452) separated according to pre-associated priorities.

6. The drive device and the load form an electromechanical integrated device, 6. The load driving system according to claim 1, wherein the control device is separate from the electro-mechanical integrated device.

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