Fluid control equipment and PWM communication method

Abstract

The invention discloses fluid control equipment and a communication method. The fluid control equipment comprises a rotor for controlling fluid, a controller and a PWM (Pulse Width Modulation) communication interface, the controller is also connected with the PWM communication interface, and the PWM communication interface comprises a three-wire system PWM; the controller can feed back the rotating speed gear of the rotor to the PWM communication interface through a PWM input and output multiplexing line in the three-wire system PWM; signals transmitted by the PWM input and output multiplexing line comprise a first interval and a second interval, the first interval represents a rotating speed command through a PWM signal, the second interval represents rotating speed gears of the rotor through high and low levels, and different combinations of the high and low levels represent rotating speeds of different gears. According to the technical scheme, the rotating speed information can be fed back by utilizing the PWM input and output multiplexing line in the three-wire system PWM.

Description

Technical Field

[0001] This application relates to the field of PWM communication control technology, specifically to a fluid control device and a PWM communication method. Background Technology

[0002] In related technologies, fluid control equipment communicates via a three-wire PWM (Pulse Width Modulation) system. This three-wire system consists of three wires: a power line, a ground line, and a PWM input / output multiplexed line. The PWM input / output multiplexed line is a single wire used to carry speed commands and fault diagnosis information. The speed command serves as the input information, and the fault diagnosis information serves as the output information. However, the output information can only reflect the fault diagnosis status and cannot provide speed information. Summary of the Invention

[0003] In view of this, this application provides a fluid control device and a PWM communication method, which can use a single PWM to feed back speed information so that the host computer can keep track of the speed of the fluid control device in a timely manner.

[0004] This application provides a fluid control device.

[0005] In view of this, this application provides a fluid control device and a PWM communication method that can utilize the data feedback capability of PWM input / output multiplexing lines.

[0006] Embodiments of this application provide a fluid control device, including: a rotor, a controller, and a PWM communication interface;

[0007] The controller is connected to the PWM communication interface, which includes a three-wire PWM.

[0008] The controller can feed back the rotor's speed range to the PWM communication interface through the PWM input / output multiplexed line in the three-wire PWM. The signal transmitted by the PWM input / output multiplexed line includes a first interval and a second interval. The first interval represents the speed command through the PWM signal, and the second interval can use high and low levels to represent the rotor's speed range. Different combinations of high and low levels represent different speed ranges.

[0009] In the fluid control device provided in this application embodiment, speed commands and speed levels can be carried and fed back to the host computer via PWM input / output multiplexing lines. This configuration improves the data feedback capability of the PWM input / output multiplexing lines.

[0010] This application also provides a PWM communication method for a fluid control device, the method comprising:

[0011] Receive the speed command on the PWM input / output multiplex line in the three-wire PWM system, and control the rotor to rotate according to the speed command.

[0012] The speed range of the rotor controlling the fluid is represented on the PWM input / output multiplexed line; the signal transmitted by the PWM input / output multiplexed line includes a first interval and a second interval. The first interval represents the speed command through the PWM signal, and the second interval can sample high and low levels to represent the speed range of the rotor. Different combinations of high and low levels represent different speed ranges.

[0013] The rotor speed range is represented on the PWM input / output multiplexed line; the signal transmitted on the PWM input / output multiplexed line includes a first interval and a second interval. The first interval represents the speed command through the PWM signal, and the second interval can sample high and low levels to represent the rotor speed range. Different combinations of high and low levels represent different speed ranges.

[0014] In the PWM communication method for fluid control equipment provided in this application, speed commands and speed gears can be carried through PWM input / output multiplexing lines and fed back to the host computer. This setting improves the data feedback capability of the PWM input / output multiplexing lines. Attached Figure Description

[0015] Figure 1 A schematic diagram of a fluid control device provided in an embodiment of this application;

[0016] Figure 2 This is a schematic diagram illustrating how a traditional PWM input / output multiplexer line carries speed commands and fault diagnosis information.

[0017] Figure 3 A signal diagram of a PWM input / output multiplexed line provided in an embodiment of this application;

[0018] Figure 4 A signal diagram of a PWM input / output multiplexed line provided in an embodiment of this application;

[0019] Figure 5 A schematic diagram of yet another speed range provided in an embodiment of this application;

[0020] Figure 6 A schematic diagram of another speed range provided in an embodiment of this application;

[0021] Figure 7 A schematic diagram illustrating another speed range provided in an embodiment of this application;

[0022] Figure 8A flowchart illustrating a PWM communication method for a fluid control device provided in an embodiment of this application. Detailed Implementation

[0023] To facilitate understanding of the fluid control device provided in the embodiments of this application, the following description uses an electronic water pump as an example. It should be understood that the fluid control device can also be an electronic oil pump, etc. As long as it uses PWM communication and includes a rotor that controls the fluid, and the fluid control device needs to provide feedback on the speed level through the PWM communication interface, the technical solution provided in the embodiments of this application can be used.

[0024] For example, electric water pumps can be used in vehicles to cool the vehicle. Specifically, the fluid control device is an electric water pump; the electric water pump is used to cool the vehicle; the electric water pump connects to the vehicle controller via a PWM communication interface.

[0025] In related technologies, PWM communication interfaces include four-wire and three-wire systems. The four-wire system consists of four wires: a power line, a ground line, a PWM input line, and a PWM output line. In this four-wire PWM communication, the PWM input line is used for speed input control and fault diagnosis feedback, while the PWM output line is used to provide feedback on the current speed range of the electric water pump. For example, for speed control, the duty cycle or frequency of the PWM signal can be adjusted to represent different speeds. Similarly, fault diagnosis feedback can also be represented using the PWM signal's duty cycle or frequency; different duty cycles can represent different faults. However, three-wire PWM cannot provide feedback on the rotor's current speed.

[0026] The fluid control device provided in this application embodiment carries rotor speed information on the PWM input / output multiplexing line.

[0027] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0028] See Figure 1 The figure is a schematic diagram of a fluid control device provided in an embodiment of this application.

[0029] The following section will use an electronic water pump as an example of a fluid control device.

[0030] The fluid control device with PWM communication provided in this application includes: a rotor for controlling fluid, a controller 100, and a PWM communication interface 300;

[0031] The controller 100 is used to control the rotor M; this application does not specifically limit the specific type of the controller 100, such as it can be a microprocessor or a single-chip microcomputer.

[0032] The controller 100 is also connected to the PWM communication interface 300, which is a three-wire PWM; the three-wire PWM includes: a power line, a ground line, and a PWM input / output multiplexed line;

[0033] The controller 100 is used to feed back the rotor speed level to the PWM communication interface 300 through the PWM input-output multiplexed line in the three-wire PWM; the signal transmitted by the PWM input-output multiplexed line includes a first interval and a second interval. The first interval represents the speed command through the PWM signal, and the second interval represents the rotor speed level through high and low levels. Different combinations of high and low levels represent different speed levels.

[0034] It should be understood that the PWM signal included in the first interval refers to a PWM signal with a fixed duty cycle and frequency. The PWM signal is used to represent the speed command issued by the host computer. Since the PWM input / output multiplexer multiplexes the input and output, the input signal is the speed command.

[0035] One possible implementation involves an electronic water pump equipped with a device to measure the rotational speed of rotor M, thus obtaining the current rotational speed of rotor M. Specifically, the controller, when the rotor is operating normally, obtains the rotor's rotational speed, determines the corresponding speed range based on this speed, and transmits the speed range on the PWM input / output multiplexed line. It should be understood that when the rotor is in any one or more of the following states: over-temperature, dry running, locked rotor, overcurrent, over / undervoltage, etc., the rotor stops operating, and these conditions do not require feedback on the speed range. Generally, feedback on the speed range is only needed when the rotor is operating normally. For example, the host computer sends a speed command to make the rotor run at 100 RPM, but whether the rotor is actually running at 100 RPM requires feedback from the rotor to the host computer. In this case, although PWM communication cannot provide feedback on the specific rotor speed, it can provide feedback on the current rotational speed range. For example, if 100 RPM corresponds to the sixth speed range, then the electronic water pump will report the rotor's rotational speed range as the sixth speed range to the host computer, and the host computer will consider the rotor to be operating normally according to the speed command.

[0036] The fluid control device provided in this application embodiment, when the PWM communication interface is a three-wire PWM, can carry speed commands and speed gears through PWM input-output multiplexing lines, enriching the function of PWM input-output multiplexing lines. It also facilitates the electronic device to feed back the speed gear to the host computer, so that the host computer can better control the operation of the electronic device, and facilitates timely intervention and adjustment when the electronic device encounters problems during operation.

[0037] For easier understanding, please refer to Figure 2 This diagram illustrates how a traditional PWM input / output multiplexer carries speed commands and fault diagnosis information.

[0038] Figure 2 This is a normal life beat signal for an electronic water pump.

[0039] Among them, T LOW The interval corresponds to the low-level region, that is, T. LOW The interval corresponds to the first interval of the second interval; T HIGH The interval corresponds to the first interval. From Figure 2 It can be seen that the duty cycle or frequency in the first interval can represent the speed command; different duty cycles or frequencies represent different speed commands. These are combined as feature combinations, which can represent fault diagnosis information. The electronic water pump can then feed this fault diagnosis information back to the host computer. Figure 2 China-Israel T LOW The time interval is 0.5s, T HIGH Taking a time interval of 4.5 seconds as an example.

[0040] In this embodiment, to carry speed ranges on the PWM input / output multiplexed line, high and low voltage levels are used within the specified range to represent the speed range. This embodiment does not specifically limit the number of speed ranges; for example, it can be any number greater than or equal to two. For ease of understanding, the following embodiment uses an electronic water pump that can feed back eight speed ranges to a host computer as an example. The host computer can be a vehicle controller.

[0041] In one possible implementation, the fluid control device provided in this application embodiment includes a start signal, a gear signal, and a stop signal in the non-PWM range; both the start signal and the stop signal are low-level; the gear signal includes a combination of high and low levels. The start signal and stop signal are set in this application embodiment to distinguish between the speed signal and the PWM signal; both the start and stop signals of the speed signal are identified by a low level.

[0042] This application does not specifically limit the number of bits in the gear signal; it can be set according to actual needs. The gear signal includes at least two high and low levels, and different combinations of the two high and low levels represent at least four speed gears. For example, 2, 3, 4, or even more bits can be used. It should be understood that the more bits, the more speed gears it represents.

[0043] To facilitate signal identification and subsequent signal processing by the controller, each bit of the signal occupies the same amount of time. For example, the gear signal includes N bits; N is an integer greater than or equal to 2. The start signal, the stop signal, and one of the N bits occupy the same amount of time in the PWM communication cycle. It should be understood that the start signal and the stop signal can have the same duration, but the duration of the start signal may not be equal to the duration of the gear signal. To represent multiple speed levels, the gear signal generally includes multiple bits, and the multi-bit gear signal uses binary to represent the speed level.

[0044] See Figure 3 The figure is a signal diagram of a PWM input / output multiplexing line provided in an embodiment of this application.

[0045] Figure 3 Only two cycles of characteristic combinations are shown, namely T LOW +T HIGH As a combination of features.

[0046] from Figure 3 It can be seen that, Figure 3 T in HIGH interval and Figure 2 T in HIGH Similar intervals exist, with the PWM signal representing the speed command.

[0047] Figure 3 T in LOW The range includes the speed settings indicated by high and low voltage levels.

[0048] To make it easier to understand, the following example will be used, continuing with T. LOW Taking a time interval of 0.5 seconds as an example, 0.5 seconds can be divided into 5 equal parts, each of which is 0.1 seconds. The first 0.1 seconds and the last 0.1 seconds are used to represent the start signal and the end signal, respectively. The three 0.1 seconds in the middle can represent eight speed gears. For example, in this embodiment, the start signal and the end signal are both at a low level for illustration.

[0049] T LOW The signal for this range is 00000, corresponding to the eighth gear speed. T LOW The signal for this interval is 00010, corresponding to the first gear speed. T LOW The signal for this interval is 00100, corresponding to the second gear speed. T LOW The signal for this interval is 00110, corresponding to the third gear speed. T LOW The signal for this range is 01000, corresponding to the fourth gear speed. T LOW The signal for this interval is 01010, corresponding to the fifth gear speed. T LOW The signal for this range is 01100, corresponding to the sixth gear speed. TLOW The signal for the interval is 01110, corresponding to the seventh gear speed.

[0050] Please refer to Table 1 below for details.

[0051] RPM gear 0.1s (first position) 0.1s 0.1s 0.1s 0.1s (tail position) 1 0 0 0 1 0 2 0 0 1 0 0 3 0 0 1 1 0 4 0 1 0 0 0 5 0 1 0 1 0 6 0 1 1 0 0 7 0 1 1 1 0 8 0 0 0 0 0

[0052] Figure 3 This is just one example, for instance. Figure 3 China T LOW The signal for the interval is 00010. After deducting the first and last bits, the three middle bits of 001 represent the speed gear, corresponding to the first speed gear.

[0053] Similarly, the embodiments provided in this application Figure 3 In this configuration, the PWM signal in the first interval is used to represent the speed command issued by the host computer; the combination of the first interval and the non-PWM interval is used to provide feedback on the rotor's fault diagnosis information.

[0054] For ease of understanding, the following explanation will use a single-cycle signal as an example.

[0055] See Figure 4 This figure is a schematic diagram of another speed range provided in an embodiment of this application.

[0056] Figure 4 T in LOW The signal in the interval is 00100. After deducting the first and last digits, the three middle digits of 010 represent the speed gear, corresponding to the second speed gear.

[0057] See Figure 5 This figure is a schematic diagram of another speed range provided in an embodiment of this application.

[0058] Figure 5 T in LOW The signal in the interval is 01000. After deducting the first and last digits, the three middle digits of 100 represent the speed gear, corresponding to the fourth speed gear.

[0059] See Figure 6 This figure is a schematic diagram of another speed gear provided in an embodiment of this application.

[0060] Figure 6 T in LOW The signal for the interval is 01110. After deducting the first and last digits, the three middle digits of 111 represent the speed gear, corresponding to the seventh speed gear.

[0061] See Figure 7 This figure is a schematic diagram of another speed range provided in an embodiment of this application.

[0062] Figure 7 T in LOWThe signal in the interval is 01100. After deducting the first and last digits, the three middle digits of 110 represent the speed gear, corresponding to the sixth speed gear.

[0063] The above are just examples of how to represent several gear positions. Other gear positions will not be described in detail. Please refer to Table 1 for the high and low level combinations.

[0064] In addition, in the embodiments of this application Figures 3-7 The example uses a three-bit gear signal to correspond to eight RPM gears. It should be understood that more bits of the gear signal can be used to represent more RPM gears. For example, the 0.5s time interval can be divided into finer time granularities, such as eight parts. The example above divides the 0.5s time interval into five equal parts. Furthermore, it should be understood that the first and last bits of the time interval do not have to be 0.1s; other values ​​can be used, such as 0.05s, with 0.4s of that time divided into three parts to represent the RPM gears.

[0065] The fluid control device with PWM communication provided in this application embodiment, when the PWM communication interface is a three-wire PWM, can carry speed commands and speed gears through the PWM input / output multiplexed line. The three different types of information enrich the function of the PWM input / output multiplexed line, and facilitate the fluid control device to feed back the speed gear to the host computer, so that the host computer can better control the operation of the fluid control device, and also facilitate the fluid control device to intervene and make adjustments in a timely manner when problems occur during operation.

[0066] The fluid control device provided in this application embodiment further includes a power supply module, a temperature acquisition module, and a current acquisition module. Figure 1 The parameters are not shown in the diagram. For example, a temperature acquisition module can detect whether the rotor is overheating, and a current acquisition module can detect whether the rotor is overcurrent. The power supply module is used to supply power to the rotor and the controller.

[0067] Based on the fluid control device provided in the above embodiments, this application also provides a PWM communication method for the fluid control device, which will be described in detail below with reference to the accompanying drawings.

[0068] See Figure 8 The figure is a flowchart of a PWM communication method for a fluid control device provided in an embodiment of this application.

[0069] The PWM communication method for a fluid control device provided in this application embodiment includes a rotor, a drive circuit, and a PWM communication interface; the rotor is connected to the drive circuit; the rotor is connected to the PWM communication interface, which is a three-wire PWM; the three-wire PWM includes a power line, a ground line, and a PWM input / output multiplexed line;

[0070] The methods include:

[0071] S801: Receives speed commands from the host computer via PWM input / output multiplexing lines;

[0072] The PWM communication method provided in this application embodiment allows the fluid control device to respond with speed gear information based on speed requests sent from the host computer. First, it receives the speed command from the host computer; only after the rotor speed has increased can speed information be collected. That is, in addition to receiving speed commands from the host computer, the fluid control device can also receive speed gear request information sent by the host computer.

[0073] S802: Feeds back the rotor speed range to the PWM communication interface through the PWM input / output multiplexed line; the signal transmitted by the PWM input / output multiplexed line includes a first interval and a second interval. In the first interval, the speed range is carried in the non-PWM interval. In the second interval, the first interval uses high and low levels to represent the rotor speed range. Different combinations of high and low levels represent different speed ranges.

[0074] It should be understood that when the rotor is in any one or more of the following states: overheating, dry running, locked rotor, overcurrent, overvoltage, or undervoltage, the rotor will stop operating, and speed feedback is not required under these conditions. Speed ​​feedback is generally only needed when the rotor is operating normally. For example, the host computer sends a speed command to make the rotor run at 100 RPM. However, whether the rotor is actually running at 100 RPM requires feedback from the rotor to the host computer. While PWM communication cannot provide the specific rotor speed, it can provide the current speed gear. For example, if 100 RPM corresponds to the sixth speed gear, then the electronic water pump will report the rotor's speed gear to the host computer as the sixth gear, and the host computer will consider the rotor to be operating normally according to the speed command.

[0075] In this embodiment, to carry speed ranges on the PWM input / output multiplexed line, high and low voltage levels are used within the specified range to represent the speed range. This embodiment does not specifically limit the number of speed ranges; for example, it can be any number greater than or equal to two. For ease of understanding, the following embodiment uses an electronic water pump that can feed back eight speed ranges to a host computer as an example. The host computer can be a vehicle controller.

[0076] The PWM communication method provided in this application embodiment, when the PWM communication interface is a three-wire PWM, can carry speed commands and speed gears through PWM input-output multiplexing lines, enriching the function of PWM input-output multiplexing lines. It also facilitates the fluid control equipment to feed back the speed gear to the host computer, so that the host computer can better control the operation of the fluid control equipment. It also facilitates the timely intervention and adjustment of the fluid control equipment when problems occur during operation.

[0077] One possible implementation is that the non-PWM range includes a start signal, a gear signal, and a stop signal; the start signal and the stop signal are both low level; the gear signal includes a combination of high and low levels.

[0078] To facilitate signal identification, the gear position signal includes N-bit signals; N is an integer greater than or equal to 2. The start signal, the stop signal, and one of the N bits occupy the same time length in the PWM communication cycle. It should be understood that the time lengths of the start signal and the stop signal can be equal, but the time length of the start signal can be different from the time length of the gear position signal.

[0079] One possible implementation involves an electronic water pump as the fluid control device; the electronic water pump is used to cool the vehicle; the host computer is the vehicle controller; and the electronic water pump is connected to the vehicle controller via a PWM communication interface.

[0080] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Regarding the methods disclosed in the embodiments, since they correspond to the devices disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the device section description.

[0081] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fluid control device, characterized in that, include: It has a rotor, controller, and PWM communication interface that can control fluid. The controller is connected to the PWM communication interface, which includes a three-wire PWM. The controller can feed back the rotor's speed range to the PWM communication interface through the PWM input / output multiplexed line in the three-wire PWM. The signal transmitted by the PWM input / output multiplexed line includes a first interval and a second interval. The first interval represents the speed command through the PWM signal, and the second interval represents the rotor's speed range through high and low levels. Different combinations of high and low levels represent different speed ranges.

2. The fluid control device according to claim 1, characterized in that, The second interval includes the start signal, gear signal, and end signal; Both the start signal and the stop signal are at a low level; The gear position signal includes a combination of high and low levels.

3. The fluid control device according to claim 1, characterized in that, The gear signal includes at least two high and low levels, and different combinations of the at least two high and low levels represent at least four speed gears.

4. The fluid control device according to claim 1, characterized in that, The gear position signal includes an N-bit signal; N is an integer greater than or equal to 2; At least one of the start signal, the stop signal, and the N-bit gear signal occupies an equal amount of time in the PWM communication cycle.

5. The fluid control device according to any one of claims 1-4, characterized in that, The combination of the first interval and the second interval can provide feedback on the fault diagnosis information of the rotor.

6. A PWM communication method for a fluid control device, characterized in that, The method includes: Obtain the speed command on the PWM input / output multiplex line in the three-wire PWM system, and control the rotor to rotate according to the speed command. The speed range of the rotor controlling the fluid is represented on the PWM input / output multiplexed line; the signal transmitted on the PWM input / output multiplexed line includes a first interval and a second interval. The first interval represents the speed command through the PWM signal, and the second interval uses high and low levels to represent the speed range of the rotor. Different combinations of high and low levels represent different speed ranges. The speed range of the rotor controlling the fluid is represented on the PWM input / output multiplexed line; the signal transmitted on the PWM input / output multiplexed line includes a first interval and a second interval. The first interval represents the speed command through the PWM signal, and the second interval uses high and low levels to represent the speed range of the rotor. Different combinations of high and low levels represent different speed ranges.

7. The PWM communication method for fluid control equipment according to claim 6, characterized in that, The second interval includes the start signal, gear signal, and end signal; Both the start signal and the stop signal are at a low level; The gear position signal includes a combination of high and low levels.

8. The PWM communication method for a fluid control device according to claim 6, characterized in that, Also includes: Fault diagnosis information is fed back through the PWM input / output multiplex line, and the combination of the first interval and the second interval is used to characterize the fault diagnosis information of the rotor.

9. The PWM communication method for a fluid control device according to claim 6, characterized in that, The gear signal includes at least two high and low levels, and different combinations of the two high and low levels represent at least four speed gears.

10. The PWM communication method for a fluid control device according to claim 6, characterized in that, The gear position signal includes an N-bit signal; N is an integer greater than or equal to 2; The start signal, the stop signal, and one of the N bits occupy the same amount of time in the PWM communication cycle.

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