CN110553783A - Pressure sensor for vehicle and pressure measuring method - Google Patents

Abstract

The invention provides a pressure sensor for vehicles and a pressure measurement method, which have low measurement cost and high measurement accuracy. The pressure sensor includes a housing and a base located in the housing, first and second sensing elements and a pressure signal processing device, the first and second sensing elements and the pressure signal processing device are all arranged on the base, and the pressure signal The processing device is respectively connected to the first and second sensing elements, and the pressure measurement method includes: sensing the pressure difference between the upstream and downstream of the engine particle trap through the first sensing element, and feeding back the pressure difference information of the gas to Pressure signal processing device; sense the absolute pressure of the gas at the downstream of the engine particulate trap through the second sensing element, and feed back the absolute pressure information to the pressure signal processing device; the pressure signal processing device will receive the pressure difference information of the gas Process with the absolute pressure information, so that the pressure difference information and the absolute pressure information can be output through one signal.

Description

Pressure sensor for vehicle and pressure measurement method

technical field

The invention relates to the technical field of automobiles, in particular to a pressure sensor and a pressure measurement method.

Background technique

With the continuous increase of the number of domestic automobiles, the environmental pollution caused by exhaust gas is becoming more and more serious. Therefore, the national standards for automobile exhaust emissions are constantly updated and stricter. "National VI" has been officially announced and will be fully implemented from 2020. In order to meet the PM (particulate matter emission) limit requirements of the new emission regulations, the currently known technical solution is to install a gasoline engine particulate filter (GPF: Gasoline Particulate Filter for short) on the exhaust pipe of the gasoline engine.

Although GPF can effectively trap particulate matter in automobile exhaust, with the increase of captured particulate matter, the pressure of exhaust gas will increase, which will affect the power and economy of the engine. Therefore, when the particles in the GPF accumulate to a certain extent, it is necessary to increase the exhaust temperature of the engine to oxidize and burn the particles in the GPF, that is, to regenerate the GPF. Furthermore, in order to trigger the regeneration of the GPF and meet the requirements of the on-board diagnostic system (OBD), it is necessary to accurately measure the pressure difference between the upstream and downstream of the GPF. In addition, in order to monitor the state of the GPF connection pipeline and meet the OBD diagnostic requirements, it is also necessary to measure the absolute pressure downstream of the GPF.

In order to meet the above measurement requirements, one of the currently known solutions is to use two pressure sensors, one of which measures the pressure difference upstream and downstream of the GPF, and the other measures the absolute pressure downstream of the GPF, but the disadvantage of this solution is that two sets of pressure sensors are required And multiple connecting pipelines, and it also needs to occupy two ECU interfaces, which significantly increases the system cost. Another solution is to use two pressure sensing modules in the same pressure sensor to measure the absolute pressure upstream and downstream of the GPF respectively, and feed back the two absolute pressure signals to the ECU. Obviously, in the second scheme, the ECU needs to do additional calculations to obtain the desired pressure difference between the upstream and downstream of the GPF, and the error of this calculation is the accumulation of the individual measurement errors of the two pressure sensing modules. Therefore, the pressure difference The accuracy is low and cannot meet the requirements of OBD diagnosis.

Contents of the invention

In view of this, the present invention provides a pressure sensor and a pressure measurement method for a vehicle, which can directly measure the pressure difference between the upper and lower reaches of the engine particle trap without calculation, and do not need to configure too many connecting pipelines, and at the same time only need It only needs to occupy one ECU interface, so the system cost is low and the measurement accuracy is high.

According to one aspect of the present invention, a pressure sensor for a vehicle is provided, including a housing, a base disposed in the housing, a first sensing element, a second sensing element and a pressure signal processing device, the The first sensing element, the second sensing element and the pressure signal processing device are all arranged on the base, and the pressure signal processing device is respectively connected to the first sensing element and the second sensing element;

Wherein, the first sensing element is used to sense the pressure difference of the gas between the upstream and downstream of the engine particle trap, and feed back the information of the pressure difference of the gas to the pressure signal processing device; the second sensing element It is used to sense the absolute pressure of the gas downstream of the engine particle trap, and feed back the absolute pressure information to the pressure signal processing device; the pressure signal processing device is used to compare the received pressure difference information of the gas with the absolute pressure The pressure information is processed so that the pressure difference information and absolute pressure information can be output through one signal.

Further, the housing is provided with a first chamber and a second chamber which are isolated from each other, and a third chamber communicated with the second chamber; the first sensing element and the Each of the second sensing elements has two opposite surfaces;

Wherein, one surface of the first sensing element is in the first chamber, and the other surface is in the third chamber; one surface of the second sensing element is in the second chamber, And the other surface is in a vacuum environment.

Further, a fourth chamber isolated from other chambers is provided in the housing, and the pressure signal processing device is disposed in the fourth chamber.

Further, the first chamber and the third chamber are arranged opposite to each other and are arranged on the same side of the base as the second chamber, and the third chamber and the fourth chamber are arranged on the same side of the base. the other side of the base.

Further, one side of the housing is provided with a first pipeline and a second pipeline, the first pipeline is used to introduce the gas upstream of the engine particle trap, and the second pipeline is used to Gases downstream of introduction into the engine particulate trap.

Further, the housing has a first side and a second side oppositely arranged, the first side is provided with a mounting flange for fixing the pressure sensor on the vehicle, and the second side is provided with a mounting flange for connecting with an external mechanism The connection port for the connection.

Further, the first side and the second side are arranged on the bottom of the casing, and the bottom is provided with a positioning bar for positioning the pressure sensor on the vehicle.

Further, the housing includes a body and a cover plate arranged at the opening of the body.

Further, the base is connected to the body and the cover through a silicone seal.

Further, the pressure signal processing device includes a circuit board and a digital application-specific integrated circuit provided on the circuit board;

The digital ASIC is used to simultaneously perform nonlinear and temperature drift compensation processing on the pressure difference information input by the first sensing element and the absolute pressure information input by the second sensing element, and process The subsequent pressure difference information and absolute pressure information are encoded, so that the pressure difference information and absolute pressure information can realize one-way signal output with a unilateral nibble digital communication protocol.

Further, both the first sensing element and the second sensing element include a strain gauge and a Wheatstone bridge arranged on the strain gauge; wherein, the first sensing element and the second sensing element The measuring elements are respectively connected to four pins through gold binding wires, and the four pins are connected to the pressure signal processing device.

Further, the gold binding wire is provided with a protective gel, and the protective gel is a fluorine-containing gel.

Further, both the first sensing element and the second sensing element are MEMS sensing elements.

Further, the pressure signal processing device is connected to the outside through three pins, one of which is used to transmit the one signal.

Further, the surface of the contact pin is gold-plated.

Further, the material of the base is epoxy resin modified material.

According to another aspect of the present invention, there is provided a pressure measurement method for a vehicle, comprising:

A housing, a base disposed in the housing, a first sensing element, a second sensing element, and a pressure signal processing device are provided, and the first sensing element, the second sensing element, and the pressure signal processing device are all Located on the base, the pressure signal processing device is respectively connected to the first sensing element and the second sensing element;

The pressure measurement method also includes:

Sensing the gas pressure difference between the upstream and downstream of the engine particulate trap through the first sensing element, and feeding back the gas pressure difference information to the pressure signal processing device;

sensing the absolute pressure of the gas downstream of the engine particulate trap through the second sensing element, and feeding back absolute pressure information to the pressure signal processing device; and

The pressure signal processing device processes the received pressure difference information and absolute pressure information of the gas, so that the pressure difference information and absolute pressure information can be output through one signal.

Further, the pressure signal processing device includes a circuit board and a digital application-specific integrated circuit arranged on the circuit board, and its operation steps include:

The digital ASIC simultaneously performs nonlinear and temperature drift compensation processing on the pressure difference information input by the first sensing element and the absolute pressure information input by the second sensing element, and converts the processed pressure The difference information and the absolute pressure information are encoded, so that the pressure difference information and the absolute pressure information realize one signal output with a single nibble digital communication protocol.

Further, the housing is provided with a first chamber and a second chamber which are isolated from each other, and a third chamber communicated with the second chamber, wherein the first sensing element senses The step of differential pressure of the gas upstream and downstream of the engine particulate trap includes:

The first sensing element senses the pressure of the gas in the first chamber through one surface, senses the pressure of the gas in the third chamber through the other surface, and senses the pressure of the gas in the first chamber according to the pressure of the gas in the first chamber and The pressure of the gas in the third chamber obtains the pressure above and downstream of the engine particulate trap;

And the step of sensing the absolute pressure of the gas downstream of the engine particulate trap by the second sensing element comprises:

The second sensing element senses the pressure of the gas in the second chamber through one surface, and senses the vacuum degree of a vacuum environment through the other surface, and according to the pressure of the gas in the second chamber and the vacuum degrees to obtain the absolute pressure downstream of the engine particulate trap.

To sum up, in the pressure sensor and pressure measurement method for vehicles provided by the present invention, only two sensing elements and a small number of connecting pipelines are needed to realize the pressure difference between the upper and lower reaches of the engine particle trap and the absolute pressure at the lower end. The measurement of the pressure signal processing device can process the information output by the two sensing elements into a signal suitable for one electrical output, and then the electrical output can be transmitted to the outside (such as the vehicle controller). Therefore, the electrical output of the electrical only takes up An external one-way interface, the system cost is low, and the desired pressure difference between the upstream and downstream of the engine particle trap is directly measured through the first sensing element, so there is no need to do additional calculations externally, the measurement error is small, and the measurement accuracy is high. High, which can more precisely control the regeneration of the engine particulate filter.

Description of drawings

The accompanying drawings are used to better understand the present invention, and do not constitute improper limitations to the present invention. in:

Fig. 1 is an exploded schematic diagram of a pressure sensor in an embodiment of the present invention;

2 is a schematic diagram of the assembly of the pressure sensor in the embodiment of the present invention;

3 is a schematic diagram of the assembly of the pressure measurement unit in the embodiment of the present invention;

Fig. 4 is a schematic diagram of the assembly of the pressure measurement unit shown in Fig. 3 after being turned over 180°;

Fig. 5 is a top view of the body of the housing in the embodiment of the present invention;

6 is a longitudinal sectional view of the pressure sensor at a first viewing angle when the cover plate is removed in the embodiment of the present invention;

FIG. 7 is a longitudinal cross-sectional view of the pressure sensor at a second viewing angle when the cover plate is provided in the embodiment of the present invention.

In the picture:

1-housing; 11-body; 110-first side; 120-second side; 130-bottom, 140-third side; 111-installation flange; 112-connection port; 113-first pipeline; 114 - second pipeline; 115-first chamber; 116-second chamber; 117-third chamber; 118-fourth chamber; 12-cover plate; 2-base; 3-first sensing Component; 4-second sensing element; 5-pressure signal processing device; 51-circuit board; 52-digital application-specific integrated circuit.

Detailed ways

In order to make the purpose and features of the present invention more obvious and easy to understand, the following will further describe the specific embodiments of the present invention in conjunction with the accompanying drawings. However, the present invention can be realized in different forms, and should not be considered as being limited to the described embodiments . As used in this specification, the singular forms "a", "an" and "the" include plural referents unless the content clearly dictates otherwise.

Fig. 1 is an exploded schematic diagram of a pressure sensor in an embodiment of the present invention, Fig. 2 is a schematic diagram of an assembly of a pressure sensor in an embodiment of the present invention, and Fig. 3 is a schematic diagram of an assembly of a pressure measurement unit in an embodiment of the present invention,

FIG. 4 is a schematic assembly diagram of the pressure measurement unit shown in FIG. 3 turned over by 180°, and it should be known that parts that are not visible in FIG. 3 and FIG. 4 are indicated by dotted lines.

As shown in FIGS. 1 to 4 , a pressure sensor includes a housing 1 and a pressure measurement unit packaged in the housing 1 . The pressure measurement unit includes a base 2, a first sensing element 3, a second sensing element 4 and a pressure signal processing device 5 arranged on the base 2, and the pressure signal processing device 5 is connected with the first sensing element respectively. The sensing element 3 is connected to the second sensing element 4. The pressure measurement method of the pressure sensor includes:

Sensing the gas pressure difference between the upstream and downstream of the gasoline engine particulate filter (GPF) through the first sensing element 3, and feeding back the pressure difference information of the gas to the pressure signal processing device 5;

Sensing the absolute pressure of the gas downstream of the gasoline engine particulate trap through the second sensing element 4, and feeding back the absolute pressure information of the gas to the pressure signal processing device 5;

The pressure signal processing device 5 processes the received absolute pressure information and pressure difference information of the gas, so that the two pieces of information can be output through one piece of signal.

Here, the pressure sensor is not limited to be used in a gasoline engine particulate trap, and may also be a diesel engine particulate trap. For this reason, the pressure sensor of the present invention is mainly used for the measurement of the pressure difference above and downstream of the particulate trap on the vehicle engine exhaust pipeline and the measurement of the downstream pressure. It is used to control the regeneration of the engine particle filter, and on the other hand, by obtaining the absolute pressure downstream of the engine particle filter, it can be used to monitor the state of the connecting pipeline on the engine particle filter, so as to meet the requirements of the on-board diagnostic system (OBD), etc. specific requirements.

Obviously, the pressure sensor of the present invention only needs two pressure sensing elements and a small amount of connecting pipelines to realize the measurement of the pressure difference between the upper and lower reaches of the engine particle trap and the measurement of the absolute pressure downstream, and the pressure signal processing device 5 can combine the two The two-way pressure information output by each sensing element is processed to be able to be output through one signal, and then the one-way signal can be transmitted to the outside, for example, to the vehicle controller (Electronic Control Unit: ECU, electronic control unit). Therefore, the one-way information Only one external interface is occupied, and the system cost is low. Moreover, the desired pressure difference between the upstream and downstream of the engine particulate filter can be directly measured through the first sensing element 3. Therefore, no additional calculations need to be performed externally, the measurement error is small, the measurement accuracy is high, and it can be more accurate Controls the regeneration of the engine particulate filter.

In this embodiment, the housing 1 may include a main body 11 and a cover plate 12 disposed at the opening of the main body 11 . The cover plate 12 and the body 11 jointly define an installation space for accommodating the pressure measurement unit. In a preferred connection manner, the cover plate 12, the body 11 and the base 2 are connected by glue, so as to achieve a good sealing effect and facilitate assembly. Further, considering the exhaust gas environment in which the pressure sensor works, the glue is preferably a high-temperature-resistant material, such as silica gel, and the material of the body 11 is also selected from a high-temperature-resistant material, such as polyphenylene sulfide (PPS) or polyethylene terephthalic acid Butylene glycol ester (PBT) glass fiber reinforcement.

Further, the body 11 has a first side 110 and a second side 120 opposite to the first side 110, wherein the first side 110 is provided with a mounting flange 111, which can fix the pressure sensor on the vehicle Above, the second side 120 can be provided with a connection port 112 for electrical output, so as to facilitate connection with the outside, such as an ECU. Preferably, the bottom 130 of the body 11 is further provided with a positioning rod S, referring to FIG. 6 and FIG. 7 , the first side 110 and the second side 120 are disposed on the bottom 130 . The positioning rod S and the mounting flange 111 can be used in cooperation to position and fix the pressure sensor on the vehicle.

The body 11 also has a third side 140 adjacent to the first side 110 and the second side 120, the third side 140 is also arranged on the bottom 130, preferably, the third side 140 A first pipeline 113 and a second pipeline 114 are arranged on it. The first pipeline 113 is used to connect with the corresponding pipeline upstream of the engine particulate trap, so as to introduce the gas upstream of the engine particulate trap into the casing 1 . The second pipeline 114 is used to connect with the corresponding pipeline downstream of the engine particulate trap, so as to introduce the gas downstream of the engine particulate trap into the casing 1 . Further, the housing 1 is provided with different chambers for storing the gas introduced by the aforementioned pipeline.

Fig. 5 is a top view of the body of the housing in the embodiment of the present invention. As shown in Fig. 5, the body 11 of the housing 1 is provided with a first chamber 115 and a second chamber 116 which are isolated, wherein the The first chamber 115 is connected to the first pipeline 113 to introduce the gas upstream of the engine particulate trap into the first chamber 115, while the second chamber 116 is connected to the second pipeline 114 to Gas downstream of the engine particulate trap is introduced into the second chamber 116 .

6 is a longitudinal sectional view of the pressure sensor in the embodiment of the present invention when the cover plate is removed at a first viewing angle. As shown in FIG. 6, the first sensing element 3 and the second sensing element 4 have opposite front faces and the back, and the front of the first sensing element 3 is set in the first chamber 115, the pressure P1 of the gas in the first chamber 115 (that is, the pressure at the upstream of the engine particulate trap) can be sensed, and simultaneously the The front of the second sensing element 4 is disposed in the second chamber 116 and can also sense the pressure P2 of the gas in the second chamber 116 (ie, the pressure downstream of the engine particulate trap). Preferably, the first chamber 115 and the second chamber 116 are arranged on the same side of the base 2 to simplify the structure and reduce the size.

In a preferred embodiment, a third chamber 117 is also provided in the housing 1, which communicates with and is opposite to the second chamber 116, for example, it can be preset between the base 2 and the body 11. Leave a channel to connect the two. Furthermore, the back surface of the first sensing element 3 is disposed in the third chamber 117 , so that the pressure P2 of the gas in the third chamber 117 can be sensed. In this way, the pressure P1 of the gas in the first chamber 115 is sensed through the front of the first sensing element 3, while the pressure P2 of the gas in the third chamber 117 is sensed from the back of the first sensing element 3, and finally according to the Two pressures, the pressure difference between the upstream and downstream of the engine particulate filter can be obtained. In this embodiment, the third chamber 117 can allow gas to flow into the back of the first sensing element 3 through a through hole. Here, through the communication of the chamber, the two sensing elements can simultaneously sense the pressure of the gas downstream of the engine particle filter, the structure is simple, easy to measure, and it can ensure that the condensed water can flow out smoothly without accumulating inside the sensor.

In addition, in this embodiment, the first sensing element 3 and the second sensing element 4 are preferably MEMS sensing elements, more preferably the second sensing element 4 itself is provided with a vacuum chamber, therefore, the The second sensing element 4 can directly sense the vacuum degree (vacuum pressure) of its vacuum chamber, so it can also directly sense the absolute pressure downstream of the engine particle trap.

Fig. 7 is a longitudinal sectional view of the pressure sensor in the embodiment of the present invention when the cover plate is installed at a second viewing angle, the second viewing angle forms an angle of 90° with the aforementioned first viewing angle, for example, the first viewing angle is the left end of the pressure sensor viewing angle, the second viewing angle is the front viewing angle of the pressure sensor. As shown in FIG. 7 , a fourth chamber 118 is further provided in the housing 1 , which is located on the same side of the base 2 as the third chamber 117 and is separated from each other. In this embodiment, the third chamber 117 and the fourth chamber 118 can be jointly defined by the body 11 and the cover plate 12, and the third chamber 17 and the fourth chamber 118 are connected by the cover plate 12 Quarantine settings. Therefore, installing the pressure signal processing device 5 in the fourth chamber 118 can realize the isolation of the measured gas from the pressure signal processing device 5, so as to prevent the pressure signal processing device 5 from being corroded by the measured gas and affecting its use. .

In this embodiment, the pressure signal processing device 5 includes a circuit board 51 and a digital application-specific integrated circuit (AISC) 52 arranged on the circuit board 51, and also includes a number of passive components arranged on the circuit board 51, such as resistors , capacitors and other auxiliary devices. Wherein, the digital ASIC 52 is used for performing nonlinear and temperature drift compensation processing on the pressure difference information input by the first sensing element 3 and the absolute pressure information input by the second sensing element 4, and processing The last two channels of information are converted into information suitable for output through one signal.

Referring to FIG. 3 and FIG. 4 , both the first sensing element 3 and the second sensing element 4 include strain gauges and a Wheatstone bridge disposed on the strain gauges. Wherein, the strain gauge is used to obtain the strain information generated by the gas pressure acting on it, and the Wheatstone bridge is used to convert the strain information into an electrical signal for output, and then the digital ASIC 52 is used for the two The electrical signal output by the Wheatstone bridge is processed for nonlinearity and temperature drift compensation, and the processed two-way electrical signal is encoded into a single-sided nibble (SENT) digital communication protocol, through which the two-way electrical signal can be The signal is transmitted to the outside through a pin, including but not limited to the ECU. In a preferred solution, the digital ASIC 52 can be an integration of multiple existing digital ASIC devices, and those skilled in the art should know how to implement a digital ASIC on the basis of the disclosure of this application document. 52 processes the two electrical signals into a signal suitable for one electrical output.

Furthermore, in order to transmit the electrical signal output by the sensing element to the digital ASIC 52 , a Wheatstone bridge needs to be connected to the circuit board 51 . In a non-limiting operation method: any sensing element is connected to multiple pins through multiple gold bonding wires (Au Bonding wires), and the multiple pins are connected to the circuit board 51 . Among them, in order to prevent the gold binding wire from being corroded by the measured gas, it is preferable to set a protective gel on the gold binding wire. The gel is preferably fluorine-containing silica gel. On the one hand, the fluorine-containing silica gel is soft and will not affect the normal pressure. On the other hand, fluorine-containing silicone has good medium resistance, which can protect the sensing element to work normally and stably in the exhaust gas environment.

Further, for any sensing element, it has four output leads, and each lead wire is connected to a pin through a gold binding wire. Measuring component connection. During actual assembly, eight pins are fixed on the base 2, and one end of each pin passes through the base 2 and is connected to the lead wire of the sensing element through a gold binding wire, and the other end also passes through the base 2 and Further inserted into the via holes on the circuit board 51 , and the connection between these pins and the circuit board 51 can be manual soldering, automatic soldering or laser soldering.

Further, as shown in Figures 3 and 4, the base 2 is also provided with three other pins, specifically, eight pins form a group and are arranged on one side of the base 2, and three pins form another group It is located on the other side of the base 2, and one end of the three pins is connected to the circuit board 51, and the connection method can also be manual soldering, automatic soldering or laser soldering. In practice, the three pins are used to integrate with the aforementioned connection port 112 to form an electrical output port. Specifically, the connection port 112 includes a cover and three contact pins disposed in the cover, and each contact pin is provided with a flat insertion piece, which can be connected to the contact pin by welding. In addition, both pins and flat inserts can be made of copper-tin alloy, and the surface is preferably gold-plated to avoid corrosion by the measuring medium. Then, in practical applications, through the single-sided nibble (SENT) digital communication protocol, two signals can be output to the outside through one of the pins, while the other pin is used for grounding, and the remaining pin is used for circuit board power supply.

Further, preferably, the material of the base 2 is selected from epoxy resin modified materials, and can be molded by injection molding. Since the epoxy resin modified material not only has a low thermal expansion coefficient, but also has good medium resistance, it can ensure the long-term stable operation of the pressure measurement unit under harsh conditions such as engine exhaust. In particular, this material and silicon-based MEMS sensor The coefficient of thermal expansion is relatively close, which can ensure that the connection of the MEMS sensor element has a small thermal stress. Therefore, in this embodiment, the first sensing element 3 and the second sensing element 4 are preferably MEMS sensing elements, which are small in size and can save space, and preferably the base 2 is provided with corresponding grooves to The first sensing element 3 and the second sensing element 4 are accommodated, and the sensing element can be fixed with the base 2 by glue, and the protective gel can be prevented from being lost through the groove.

Further, the assembly process of the pressure sensor of this embodiment preferably includes the following steps:

First, glue is dispensed inside the body 11, such as in a glue tank; the glue and the glue bonded in the pressure measurement unit are preferably the same;

Then, put the pressure measurement unit into the body 11; in order to seal the pressure measurement unit and the housing 1 well, it is preferable that the periphery of the base 2 is provided with edges, which can enhance the glue bonding strength between the pressure measurement unit and the housing 1 ;

After that, the three pins can be welded together with the three flat inserts fixed on the body 11 by resistance welding;

Subsequently, glue dispensing can be continued, and the cover plate 12 can be installed;

Next, the glue is cured at high temperature, so that the pressure measurement unit is fixed to the body 11 and the cover plate 12;

Finally, air tightness and function tests are performed.

Thus, by obtaining the pressure sensor of the present embodiment, the following benefits can be obtained:

First, the pressure sensor only needs two sensing elements and a small number of connecting pipelines to realize the measurement of the pressure difference above and downstream of the engine particulate trap and the measurement of the absolute pressure downstream, and the two sensing elements can be integrated through a digital application-specific integrated circuit. The signal output by the test element is processed into a signal suitable for one electrical output, and then the electrical output can be transmitted to the outside. Therefore, this electrical only occupies an external interface, and the system cost is low;

Second, the pressure sensor directly measures the desired pressure difference between the upper and lower reaches of the engine particle trap through the first sensing element, therefore, no additional calculations need to be performed externally, the measurement error is small, the measurement accuracy is high, and it can be more accurate. For precise control of engine particulate filter regeneration;

Third, the pressure sensor sets two sensing elements and a digital ASIC on the same base, which can realize calibration and testing at the module level, and is convenient for early stage development and testing;

Fourth, the pressure sensor forms isolated chambers and pipelines for introducing gas through the shell structure, so as to ensure that the condensed water can flow out smoothly and not accumulate inside the sensor, ensuring that the pressure sensor can be used stably for a long time;

Fifth, the assembly process of the pressure sensor is simpler, the production efficiency is improved, and the production cost is lower.

Finally, it should be noted that the preferred embodiments of the present invention are as described above, but are not limited to the scope disclosed in the above embodiments. For example, the layout of each chamber in the housing is not particularly limited. In addition, the two pipelines can also be Self-contained or provided externally. In addition, the pressure signal processing device 5 can use existing PLC and other control devices. Those skilled in the art should know how to realize the control device and the sensing element on the basis of the content disclosed in this application. and external communication connections.

Obviously, those skilled in the art can make various changes and modifications to the invention without departing from the spirit and scope of the invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (19)

1. A pressure sensor for a vehicle, characterized in that it comprises a housing and a base disposed in the housing, a first sensing element, a second sensing element and a pressure signal processing device, the first The sensing element, the second sensing element and the pressure signal processing device are all arranged on the base, and the pressure signal processing device is respectively connected to the first sensing element and the second sensing element; Wherein, the first sensing element is used to sense the pressure difference of the gas between the upstream and downstream of the engine particle trap, and feed back the information of the pressure difference of the gas to the pressure signal processing device; the second sensing element It is used to sense the absolute pressure of the gas downstream of the engine particle trap, and feed back the absolute pressure information to the pressure signal processing device; the pressure signal processing device is used to compare the received pressure difference information of the gas with the absolute pressure The pressure information is processed so that the pressure difference information and absolute pressure information can be output through one signal. 2. The pressure sensor for a vehicle according to claim 1, wherein a first chamber and a second chamber which are isolated from each other are provided in the housing, and a chamber connected to the second chamber is also provided. a communicating third chamber; the first sensing element and the second sensing element each have two opposing surfaces; Wherein, one surface of the first sensing element is in the first chamber, and the other surface is in the third chamber; one surface of the second sensing element is in the second chamber, And the other surface is in a vacuum environment. 3. The pressure sensor for vehicles according to claim 2, characterized in that, a fourth chamber isolated from other chambers is also provided in the housing, and the pressure sensor is provided in the fourth chamber. Signal processing device. 4 . The pressure sensor for vehicles according to claim 3 , wherein the first chamber is disposed opposite to the third chamber and is disposed on the same side of the base as the second chamber , the third chamber and the fourth chamber are disposed on the other side of the base. 5. The pressure sensor for vehicles according to claim 1, wherein a first pipeline and a second pipeline are provided on one side of the housing, and the first pipeline is used to introduce the Gas upstream of the engine particulate trap, the second conduit for introducing gas downstream of the engine particulate trap. 6. The pressure sensor for a vehicle according to claim 1, wherein the housing has a first side and a second side oppositely disposed, and the first side is provided with a wall for fixing the pressure sensor to the vehicle. On the mounting flange, the second side is provided with a connection port for connecting with an external mechanism. 7. The pressure sensor for vehicles according to claim 6, wherein the first side and the second side are disposed on the bottom of the housing, and the bottom is provided with a Position the pressure sensor on the positioning bar above the vehicle. 8 . The pressure sensor for a vehicle according to claim 1 , wherein the housing comprises a body and a cover disposed at an opening of the body. 9 . 9 . The pressure sensor for vehicles according to claim 8 , wherein the base is connected to the body and the cover through a silicone seal. 10. The pressure sensor for a vehicle according to claim 1, wherein the pressure signal processing device comprises a circuit board and a digital application-specific integrated circuit disposed on the circuit board; The digital ASIC is used to simultaneously perform nonlinear and temperature drift compensation processing on the pressure difference information input by the first sensing element and the absolute pressure information input by the second sensing element, and process the processed The pressure difference information and the absolute pressure information are encoded, so that the pressure difference information and the absolute pressure information can realize one signal output with a unilateral nibble digital communication protocol. 11. The pressure sensor for vehicles according to claim 1, characterized in that, both the first sensing element and the second sensing element comprise strain gauges and Wheatstone electrodes arranged on the strain gauges Bridge; wherein, the first sensing element and the second sensing element are respectively connected to four pins through gold binding wires, and the four pins are connected to the pressure signal processing device. 12 . The pressure sensor for vehicles according to claim 11 , wherein a protective gel is provided on the gold binding wire, and the protective gel is a fluorine-containing gel. 13 . 13. The pressure sensor according to claim 11, wherein the first sensing element and the second sensing element are both MEMS sensing elements. 14 . The pressure sensor for a vehicle according to claim 1 , wherein the pressure signal processing device is connected to the outside through three pins, one of which is used to transmit the one-way signal. 15. The pressure sensor for vehicles according to claim 11 or 14, characterized in that the surface of the pin is gold-plated. 16 . The pressure sensor for vehicles according to claim 1 , wherein the base is made of epoxy resin modified material. 17. A pressure measurement method for a vehicle, comprising: A housing, a base disposed in the housing, a first sensing element, a second sensing element, and a pressure signal processing device are provided, and the first sensing element, the second sensing element, and the pressure signal processing device are all Located on the base, the pressure signal processing device is respectively connected to the first sensing element and the second sensing element; The pressure measurement method also includes: Sensing the gas pressure difference between the upstream and downstream of the engine particulate trap through the first sensing element, and feeding back the gas pressure difference information to the pressure signal processing device; sensing the absolute pressure of the gas downstream of the engine particulate trap through the second sensing element, and feeding back absolute pressure information to the pressure signal processing device; and The pressure signal processing device processes the received pressure difference information and absolute pressure information of the gas, so that the pressure difference information and absolute pressure information can be output through one signal. 18. The pressure measurement method for a vehicle according to claim 17, wherein the pressure signal processing device comprises a circuit board and a digital application-specific integrated circuit disposed on the circuit board, and its operating steps include: The digital ASIC simultaneously performs nonlinear and temperature drift compensation processing on the pressure difference information input by the first sensing element and the absolute pressure information input by the second sensing element, and converts the processed pressure The difference information and the absolute pressure information are encoded, so that the pressure difference information and the absolute pressure information can realize one signal output with a unilateral nibble digital communication protocol. 19. The pressure measurement method for a vehicle according to claim 17, wherein a first chamber and a second chamber that are isolated from each other are provided in the housing, and a chamber that is connected to the second chamber is also provided. The third chamber communicated with the chamber, wherein the step of sensing the pressure difference of the gas upstream and downstream of the engine particulate trap by the first sensing element comprises: The first sensing element senses the pressure of the gas in the first chamber through one surface, senses the pressure of the gas in the third chamber through the other surface, and senses the pressure of the gas in the first chamber according to the pressure of the gas in the first chamber and the pressure of the gas in the third chamber, obtaining the pressure difference above and downstream of the engine particulate trap; And the step of sensing the absolute pressure of the gas downstream of the engine particulate trap by the second sensing element comprises: The second sensing element senses the pressure of the gas in the second chamber through one surface, and senses the vacuum degree of a vacuum environment through the other surface, and according to the pressure of the gas in the second chamber and the vacuum degrees to obtain the absolute pressure downstream of the engine particulate trap.