Oxygen heating system

Abstract

The present invention provides an oxygen heating system integrated within an engine chip electrically connected to a main control chip. The system includes at least two oxygen heating modules, each of which comprises a heating control unit that outputs a drive control signal based on a parallel oxygen heating control signal, a serial oxygen heating control signal, and a fault detection signal; a drive unit that controls the operating state of the corresponding heating element based on the drive control signal; and a fault detection module that detects faults in the oxygen heating module. Thus, the present invention integrates multiple oxygen heating modules within the engine chip, enabling the chip to independently heat and detect faults for each oxygen sensor. This reduces peripheral circuitry while improving reliability and minimizing complexity.

Description

Technical Field

[0001] The present invention relates to the field of small engines, and in particular to an oxygen heating system. Background Art

[0002] With the continuous upgrading of environmental regulations, reducing motorcycle emissions has become an industry priority. Motorcycle fuel supply systems are gradually transitioning from carburetors to electronic fuel injection systems. Through precise ignition and injection control, these systems significantly reduce exhaust emissions and meet higher environmental standards.

[0003] In existing electronic fuel injection systems, oxygen sensor heating is crucial to meet environmental regulations requiring precise oxygen sensor monitoring. The oxygen sensor heater quickly heats the sensor to its optimal operating temperature, ensuring real-time monitoring of exhaust gas oxygen levels. However, common engine chips currently only feature a single oxygen sensor heater driver circuit. This circuit cannot independently heat multiple oxygen sensors, nor can it accommodate the heating requirements of both front and rear oxygen sensors in a single-cylinder engine. Furthermore, achieving multi-channel drive and diagnostic functionality requires the design of complex peripheral and diagnostic circuits, increasing hardware cost and design complexity while also reducing system reliability.

[0004] Therefore, how to ensure the independent driving of the oxygen heating system of the engine system with good reliability and low complexity has become a technical problem that the industry urgently needs to solve. Summary of the Invention

[0005] The present invention provides an oxygen heating system, which solves the technical problem of how to ensure independent driving of the oxygen heating system of an engine system with good reliability and low complexity.

[0006] According to a first aspect of the present invention, an embodiment of the present invention provides an oxygen heating system, the oxygen heating system being integrated within an engine chip. The system comprises N oxygen heating modules, each of which is configured to heat a corresponding oxygen sensor, where N is an integer greater than or equal to 2.

[0007] The engine chip is electrically connected to the main control chip, and the engine chip includes an SPI module, which is used to receive the SPI control signal sent by the main control chip and output corresponding serial oxygen heating control signals to each oxygen heating module based on the SPI control signal;

[0008] The main control chip also outputs corresponding parallel oxygen heating control signals to each oxygen heating module; wherein:

[0009] The oxygen heating module comprises:

[0010] a heating control unit, receiving the parallel oxygen heating control signal, the serial oxygen heating control signal, and the fault detection signal, and configured to output a drive control signal based on the parallel oxygen heating control signal, the serial oxygen heating control signal, and the fault detection signal;

[0011] A driving unit, comprising a high-side driver, a clamping sub-unit, and a first MOS transistor, wherein an input end of the high-side driver receives the driving control signal, and an output end thereof is respectively coupled to a first end of the clamping sub-unit and a control end of the first MOS transistor, a second end of the clamping sub-unit and a drain of the first MOS transistor are both coupled to a first node, the first node is further coupled to a first end of a corresponding heating element, and a source of the first MOS transistor is grounded;

[0012] a fault detection module having a first end coupled to the source of the first MOS transistor, a second end coupled to the first node, and an output end coupled to the heating control unit, for outputting the fault detection signal based on the current flowing through the source of the first MOS transistor and the voltage of the first node.

[0013] Optionally, the drive control signal includes an on-drive signal and an off-drive signal, and outputting the drive control signal based on the parallel oxygen heating control signal, the serial oxygen heating control signal, and the fault detection signal includes:

[0014] When the parallel oxygen heating control signal is characterized as being on and the serial oxygen heating control signal is characterized as being off, the heating control unit outputs the on drive signal;

[0015] When the parallel oxygen heating control signal is characterized as being off and the serial oxygen heating control signal is characterized as being on, the heating control unit outputs the on drive signal;

[0016] When the parallel oxygen heating control signal is characterized as being on and the serial oxygen heating control signal is characterized as being on, the heating control unit outputs the shutoff drive signal;

[0017] When the parallel oxygen heating control signal is characterized as off and the serial oxygen heating control signal is characterized as off, the heating control unit outputs the off drive signal;

[0018] When the fault detection signal indicates an abnormality, the heating control unit outputs the shutdown drive signal.

[0019] Optionally, the fault detection module is further configured to:

[0020] When the heating control unit outputs the turn-on drive signal, outputting the fault detection signal based on the current flowing through the source of the first MOS transistor;

[0021] When the heating control unit outputs the shutdown driving signal, the failure detection signal is output based on the voltage of the first node.

[0022] Optionally, the method of outputting the fault detection signal based on the current flowing through the source of the first MOS transistor and the voltage of the first node includes:

[0023] When the heating control unit outputs the turn-on drive signal, if the current flowing through the source of the first MOS transistor is greater than or equal to a first current threshold, outputting the fault detection signal indicating an abnormality;

[0024] When the heating control unit outputs the on-drive signal, if the current flowing through the source of the first MOS transistor is less than the first current threshold, the fault detection signal indicating normal operation is output;

[0025] When the heating control unit outputs the shutdown driving signal, if the voltage of the first node does not fall within a second threshold voltage range, outputting the fault detection signal indicating an abnormality;

[0026] When the heating control unit outputs the shutdown driving signal, if the voltage of the first node falls within the second threshold voltage range, the fault detection signal indicating normality is output.

[0027] Optionally, the fault detection signal includes an overcurrent detection signal, and the fault detection module includes an overcurrent detection unit; the overcurrent detection unit includes a first amplifier and a detection resistor;

[0028] A first end of the detection resistor is coupled to the source of the first MOS transistor, and a second end thereof is grounded;

[0029] The first input terminal of the first amplifier is coupled to the first terminal of the detection resistor, the second terminal thereof is coupled to the second terminal of the detection resistor, and the output terminal thereof is coupled to the heating control unit for outputting the overcurrent detection signal.

[0030] Optionally, the heating control unit is configured as:

[0031] Based on the overcurrent detection signal and the overcurrent filtering time, it is determined whether a circuit fault occurs, wherein:

[0032] If the overcurrent detection signal is characterized as abnormal and the duration is greater than the overcurrent filtering time, it is determined that the circuit has an overcurrent and the shutdown drive signal is output.

[0033] Optionally, the heating control unit is further coupled to a status indicator light, and the heating control unit is configured to:

[0034] When overcurrent occurs in the circuit, the status indicator light is controlled to turn off.

[0035] Optionally, the fault detection signal includes an open circuit detection signal and a short circuit detection signal; the maximum value of the second threshold voltage range is a first set voltage, and the minimum value thereof is a second set voltage; the fault detection module includes an open circuit detection unit, a short circuit detection unit, and a voltage setting unit;

[0036] The voltage setting unit includes a second amplifier and a first switch, wherein a first input terminal of the second amplifier receives the first setting voltage, a second input terminal of the second amplifier is coupled to an output terminal of the second amplifier, an output terminal of the second amplifier is coupled to a first terminal of the first switch, and a second terminal of the first switch is coupled to the first node;

[0037] The open circuit detection unit includes a third amplifier, a first input terminal of the third amplifier receives a third set voltage, a second input terminal of the third amplifier is coupled to the first terminal of the first switch, and an output terminal of the third amplifier is coupled to the heating control unit, wherein the third set voltage is greater than the first set voltage;

[0038] The short circuit detection unit includes a fourth amplifier, a first input terminal of the fourth amplifier receives the second set voltage, a second input terminal of the fourth amplifier is coupled to the first terminal of the first switch, and an output terminal of the fourth amplifier is coupled to the heating control unit.

[0039] Optionally, the heating control unit is further coupled to the control end of the first switch, and the heating control unit is configured as follows:

[0040] When the heating control unit outputs the shutdown driving signal, the first switch is controlled to be turned on.

[0041] Optionally, the heating control unit is configured as follows:

[0042] Based on the open circuit detection signal and the open circuit filtering time, it is determined whether a circuit fault occurs, wherein:

[0043] If the open circuit detection signal is abnormal and the duration is greater than the open circuit filtering time, it is determined that the circuit is open circuited and the shutdown drive signal is output; and

[0044] Based on the short-circuit detection signal and the short-circuit filtering time, it is determined whether a circuit fault occurs, wherein:

[0045] If the short-circuit detection signal is abnormal and lasts longer than the short-circuit filtering time, it is determined that a short circuit to ground occurs in the circuit, and the shutdown drive signal is output.

[0046] Optionally, the engine chip further includes:

[0047] a power supply module, configured to supply power to the engine chip and a sensor electrically connected to the engine chip;

[0048] a mode control module, receiving a key signal and configured to control the state of the engine chip to be an operating mode or a standby mode based on the key signal;

[0049] an injector driving module, coupled to the injector, for driving the injector when the engine chip is in a working mode;

[0050] a relay driving module, coupled to the relay, for driving the relay when the engine chip is in an operating mode;

[0051] a speed module, coupled to the tachometer, for outputting a speed signal when the engine chip is in an operating mode;

[0052] a fault light driving module, coupled to the fault indicator light, for driving the fault indicator light when the system is in a fault state;

[0053] an idle stepper motor driving module, coupled to the idle stepper motor, and configured to drive the idle stepper motor when the engine chip is in a working mode;

[0054] a magnetoelectric signal processing module, configured to convert crankshaft magnetoelectric signals when the engine chip is in an operating mode;

[0055] K-LINE communication module, used to implement OBD communication.

[0056] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0057] The oxygen heating system of the present invention is integrated within an engine chip, which is electrically connected to a main control chip. The system includes at least two oxygen heating modules, each of which comprises a heating control unit that outputs a drive control signal based on a parallel oxygen heating control signal, a serial oxygen heating control signal, and a fault detection signal; a drive unit that controls the operating state of the corresponding heating element based on the drive control signal; and a fault detection module that detects faults in the oxygen heating module. Thus, the present invention integrates multiple oxygen heating modules within the engine chip, enabling the chip to independently heat and detect faults for each oxygen sensor. This reduces peripheral circuitry while improving reliability and reducing complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0059] Figure 1 It is a structural diagram of an engine chip in the prior art;

[0060] Figure 2 This is a schematic structural diagram of an engine chip provided by one embodiment of the present invention;

[0061] Figure 3 This is a schematic diagram of the structure of the oxygen heating system provided by one embodiment of the present invention. Figure 1 ;

[0062] Figure 4 corresponds to Figure 3 Working waveform of oxygen heating system Figure 1 ;

[0063] Figure 5 This is a schematic diagram of the structure of the oxygen heating system provided by one embodiment of the present invention. Figure 2 ;

[0064] Figure 6 This is a schematic diagram of the structure of an oxygen heating system provided by an embodiment of the present invention. Figure 3 ;

[0065] Figure 7 corresponds to Figure 5 The working waveform of the engine chip Figure 4 .

[0066] Reference numerals:

[0067] 11-SPI module;

[0068] 12-Oxygen heating system;

[0069] 13-bus;

[0070] 121- oxygen heating module;

[0071] 1211-heating control unit;

[0072] 12121-high side driver;

[0073] 12122-clamp subunit;

[0074] 1213-Fault detection module;

[0075] 12131-first amplifier;

[0076] 12132-second amplifier;

[0077] S1-first switch;

[0078] 12133-third amplifier;

[0079] 12134-fourth amplifier;

[0080] R sense - Sense resistor;

[0081] 1214-heating element;

[0082] INO2Hx-parallel oxygen heating control signal;

[0083] M1-first MOS tube. DETAILED DESCRIPTION

[0084] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0085] The terms "first," "second," "third," "fourth," and the like (if any) in the description and claims of the present invention and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatus.

[0086] The technical solution of the present invention is described in detail below with reference to specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0087] As described in the background art, it is difficult to ensure that the oxygen heating system of the engine system is independently driven with good reliability and low complexity in the existing technology.

[0088] Figure 1 It is a schematic diagram of the structure of the engine chip in an embodiment.

[0089] As you can see, the chip includes:

[0090] VDD module, used to power the engine chip;

[0091] The VDD follower module is used to power external sensors. Its voltage output VDD_TR follows the voltage output VDD of the VDD module.

[0092] KEY module, used to power on the chip;

[0093] Specifically, when the KEY signal is high, the chip enters the working mode;

[0094] When the KEY signal is low, the chip enters standby mode.

[0095] The SPI module is used for communication between the main control chip and the engine chip to realize the opening of the ignition switch and read diagnostic information.

[0096] Stepper Driver: used to drive the engine's idle air stepper motor.

[0097] Injector driver module (INJ), used to drive the engine's injectors.

[0098] The O2H module is used to drive the oxygen sensor heater and provide the necessary preheating function for the oxygen sensor to quickly enter the working state. The oxygen sensor is used for exhaust gas detection.

[0099] The relay driver module (Relay Driver) is used to drive the oil pump relay and other relays to realize the start and stop control of external devices (such as oil pumps, fans, etc.).

[0100] The LSD module is used to drive the fault light. When a system fault (such as overcurrent or short circuit) is detected, the fault light will be turned on to alert the user.

[0101] The speed output drive module (TACH) is used to drive the speed output. Specifically, it can drive the tachometer display to output the real-time engine speed signal.

[0102] K-line is used for OBD (On-Board Diagnostics) communication, transmitting diagnostic information and system status.

[0103] It can be seen that in the engine system where this chip is located, the system can only heat one oxygen sensor. This makes this driving solution difficult to apply in the engine.

[0104] Specifically, in a single-cylinder engine, the exhaust system is usually equipped with front and rear oxygen sensors, which are used for air-fuel ratio control and emission monitoring respectively. Since the O2H module cannot achieve independent heating of the front and rear oxygen sensors, more engine chips are required for separate control.

[0105] In a two-cylinder, dual-oxygen engine, each cylinder needs to be equipped with an oxygen sensor. The existing single-channel drive solution is obviously unable to achieve independent heating of the oxygen sensor as needed.

[0106] Even if the system can heat all oxygen sensors simultaneously, actual implementation requires additional peripheral circuitry. This not only increases design and development costs but also places higher demands on hardware wiring and electrical reliability, leading to increased points of failure, reduced system reliability, and greater risk.

[0107] Not only that, in actual implementation, the engine chip also needs to add peripheral diagnostic circuits to achieve safe management of the O2H module, which has many unreliable factors and greater risks.

[0108] In light of this, the technical solution of the present invention provides an oxygen heating system integrated within an engine chip, which is electrically connected to a main control chip. The system includes at least two oxygen heating modules, each of which includes: a heating control unit that outputs a drive control signal based on a parallel oxygen heating control signal, a serial oxygen heating control signal, and a fault detection signal; a drive unit that controls the operating state of the corresponding heating element based on the drive control signal; and a fault detection module that detects faults in the oxygen heating module. Thus, the present invention integrates multiple oxygen heating modules within the engine chip, enabling the chip to independently heat and detect faults for each oxygen sensor. This reduces peripheral circuitry while improving reliability and reducing complexity.

[0109] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0110] In practical applications, the engine system may have multiple chips. The engine chip in the embodiment of the present invention is electrically connected to the main control chip, and the oxygen heating system provided by the embodiment of the present invention is integrated inside the engine chip.

[0111] In the embodiments of the present invention, please refer to Figure 2 The engine chip includes an SPI module 11, which is used to receive SPI control signals (CS, SCK, SI, SO) sent by the main control chip (not shown in the figure) and output corresponding serial oxygen heating control signals to the oxygen heating system 12 based on the SPI control signals;

[0112] The main control chip also outputs corresponding parallel oxygen heating control signals to the oxygen heating system 12 .

[0113] It can be seen that the oxygen heating system 12 of the present invention can be controlled by a parallel oxygen heating control signal or a serial oxygen heating control signal.

[0114] In actual use, the engine chip provided by the present invention can also be used to achieve other functions, please continue to refer to Figure 2 , the engine chip further includes:

[0115] A power supply module 13 is used to supply power to the engine chip 1 and sensors electrically connected to the engine chip 1;

[0116] A mode control module 14 receives a key signal KEY and is used to control the state of the engine chip to be an operating mode or a standby mode based on the key signal KEY;

[0117] an injector driving module 15 , coupled to the injector, for driving the injector when the engine chip 1 is in a working mode;

[0118] a relay driving module 16 , coupled to the relay, for driving the relay when the engine chip 1 is in a working mode;

[0119] a speed module 17 , coupled to a tachometer, for outputting a speed signal when the engine chip 1 is in a working mode;

[0120] a fault light driving module 18, coupled to the fault indicator light, for driving the fault indicator light when the system is in a fault state;

[0121] an idle stepper motor driving module 19, coupled to the idle stepper motor, for driving the idle stepper motor when the engine chip 1 is in working mode;

[0122] a magnetoelectric signal processing module 20 for converting crankshaft magnetoelectric signals when the engine chip 1 is in working mode;

[0123] The K-LINE communication module 21 is used to implement OBD communication.

[0124] Of course, the present invention does not limit the functions that the engine chip can provide. As long as it includes the oxygen heating system 12 provided by any of the above items of the present invention, it is within the protection scope of the present invention.

[0125] In one embodiment, the oxygen heating system 12 provided in an embodiment of the present invention includes N oxygen heating modules, each of which is used to heat a corresponding oxygen sensor, where N is an integer greater than or equal to 2.

[0126] In this case, the SPI module 11 is used to receive the SPI control signal sent by the main control chip, and output corresponding serial oxygen heating control signals to each oxygen heating module based on the SPI control signal.

[0127] In an embodiment of the present invention, the oxygen heating module communicates with the SPI module 11 via a bus 13 .

[0128] In practical applications, the SPI module 11 has a register, and each oxygen heating module in the register corresponds to two SPI bits, and the values ​​of the two SPI bits are controlled by the SPI control signal.

[0129] Table 1 Status table of two SPI bits corresponding to the xth oxygen heating module

[0130]

[0131] Table 1 shows the bit operations corresponding to the xth oxygen heating module in the register and the corresponding serial oxygen heating control signal status provided by an embodiment of the present invention. It can be seen that the operating status of each oxygen heating module is controlled independently. Here, x is an integer, and 1≤x≤N.

[0132] Furthermore, the configuration of the above-mentioned main control chip should be understood as outputting corresponding parallel oxygen heating control signals to each oxygen heating module.

[0133] In actual applications, those skilled in the art may choose to control ignition through the main control chip (i.e., parallel oxygen heating control signal drive) or through the SPI module 11 (i.e., serial oxygen heating control signal drive) according to actual usage requirements.

[0134] exist Figure 2 In the example, the oxygen heating system 12 includes two oxygen heating modules, each of which receives a corresponding parallel oxygen heating control signal (INO2Hx) and a serial oxygen heating control signal, and outputs a corresponding drive to a corresponding heating element (not shown in the figure).

[0135] The structure of a single oxygen heating module is now further explained.

[0136] Please refer to Figure 3 In a specific embodiment, the oxygen heating module 121 includes:

[0137] The heating control unit 1211 receives the parallel oxygen heating control signal INO2Hx, the serial oxygen heating control signal, and the fault detection signal, and is configured to output a driving control signal based on the parallel oxygen heating control signal INO2Hx, the serial oxygen heating control signal, and the fault detection signal;

[0138] a driving unit, comprising a high-side driver 12121, a clamping sub-unit 12122, and a first MOS transistor M1; an input end of the high-side driver 12121 receives the driving control signal, and an output end thereof is coupled to a first end of the clamping sub-unit 12122 and a control end of the first MOS transistor M1, respectively; a second end of the clamping sub-unit 12122 and a drain of the first MOS transistor M1 are both coupled to a first node, which is further coupled to a first end of a corresponding heating element 1214; and a source of the first MOS transistor M1 is grounded;

[0139] The fault detection module 1213 has a first end coupled to the source of the first MOS transistor M1, a second end coupled to the first node, and an output end coupled to the heating control unit 1211, and is configured to output the fault detection signal based on the current flowing through the source of the first MOS transistor M1 and the voltage of the first node.

[0140] exist Figure 3 In the example, the clamping subunit 12122 includes a clamping diode. It should be understood that the present invention is not limited to the specific structure of the clamping subunit 12122. As long as the circuit can achieve the clamping function, it is within the protection scope of the present invention.

[0141] As an example, in Figure 3 In the example, the first MOS transistor M1 may be an NDMOS transistor. Of course, the present invention is not limited to a specific type of MOS transistor, and may also be a BJT transistor, etc. Those skilled in the art may select a suitable component as needed.

[0142] Since the heating element 1214 needs to be placed near the oxygen sensor, generally, the heating element 1214 is placed outside the chip.

[0143] It can be seen that the present invention integrates a multi-channel oxygen heating module inside the engine chip, so that the engine chip can meet the independent heating and independent fault detection requirements of each oxygen sensor. While reducing peripheral circuits, it has good reliability and low complexity.

[0144] In a specific embodiment, the driving control signal includes an on-driving signal and an off-driving signal.

[0145] In this case, the method of outputting the driving control signal based on the parallel oxygen heating control signal INO2Hx, the serial oxygen heating control signal, and the fault detection signal includes:

[0146] When the parallel oxygen heating control signal INO2Hx is on and the serial oxygen heating control signal INO2Hx is off, the heating control unit 1211 outputs the on drive signal.

[0147] When the parallel oxygen heating control signal INO2Hx is characterized as off and the serial oxygen heating control signal is characterized as on, the heating control unit 1211 outputs the on drive signal;

[0148] When the parallel oxygen heating control signal INO2Hx is characterized as being on and the serial oxygen heating control signal is characterized as being on, the heating control unit 1211 outputs the shutoff drive signal;

[0149] When the parallel oxygen heating control signal INO2Hx is characterized as off and the serial oxygen heating control signal is characterized as off, the heating control unit 1211 outputs the off drive signal;

[0150] When the fault detection signal indicates an abnormality, the heating control unit 1211 outputs the shutdown driving signal.

[0151] The above control method should be understood as follows: for the convenience of customers, the heating control unit 1211 of the present invention is controlled in two ways: parallel control and serial control. In order to drive the heating control unit 1211 more conveniently, no additional register is added to the heating control unit to receive the parallel oxygen heating control signal INO2Hx and the serial oxygen heating control signal, but an exclusive OR method is used for control.

[0152] In practical applications, both the parallel oxygen heating control signal INO2Hx and the serial oxygen heating control signal can be represented as on and off by using high and low levels. In this case:

[0153] When the parallel oxygen heating control signal INO2Hx is at a fixed level (e.g., a low level), the on / off of the first switch S1 can be controlled via the serial SPI;

[0154] Similarly, when the serial SPI sends a fixed instruction, the on and off of the first switch S1 can be controlled in parallel.

[0155] Therefore, the present invention ensures that the first switch S1 is controlled to be on or off only when a valid command is received.

[0156] In practical applications, the heating control unit 1211 can be understood as outputting a driving control signal based on the parallel oxygen heating control signal INO2Hx and the serial oxygen heating control signal when the current fault detection signal indicates normal.

[0157] When the current fault detection signal is characterized as abnormal, the shutdown drive signal is output.

[0158] Now combined Figure 4 The change of the driving control signal is described. Figure 4 FIG. 1 shows a working waveform diagram of the heating control unit 1211, wherein:

[0159] INO2Hx can be understood as the parallel oxygen heating control signal corresponding to the xth oxygen heating module;

[0160] SPI, which can be understood as the serial oxygen heating control signal corresponding to the xth oxygen heating module;

[0161] O2Hx can be understood as the driving control signal corresponding to the xth oxygen heating module.

[0162] It can be seen that, for the heating control unit 1211, the parallel oxygen heating control signal INO2Hx and the serial oxygen heating control signal of the present invention are in an exclusive OR relationship, which ensures the safety of the oxygen heating module.

[0163] In one embodiment, the fault detection module 1213 performs different detections on the oxygen heating module when the heating control unit 1211 outputs different drive control signals.

[0164] In this case, in a specific implementation, the fault detection module 1213 is further configured to:

[0165] When the heating control unit 1211 outputs the turn-on driving signal, the fault detection signal is output based on the current flowing through the source of the first MOS transistor M1;

[0166] When the heating control unit 1211 outputs the shutdown driving signal, the fault detection signal is output based on the voltage of the first node.

[0167] On this basis, the method for outputting the fault detection signal based on the current flowing through the source of the first MOS transistor M1 and the voltage of the first node includes:

[0168] When the heating control unit 1211 outputs the on-drive signal, if the current flowing through the source of the first MOS transistor M1 is greater than or equal to the first current threshold, the fault detection signal indicating abnormality is output;

[0169] When the heating control unit 1211 outputs the on-driving signal, if the current flowing through the source of the first MOS transistor M1 is less than the first current threshold, the fault detection signal indicating normal operation is output;

[0170] When the heating control unit 1211 outputs the shutdown driving signal, if the voltage of the first node does not fall within the second threshold voltage range, the fault detection signal indicating abnormality is output;

[0171] When the heating control unit 1211 outputs the shutdown driving signal, if the voltage of the first node falls within the second threshold voltage range, the fault detection signal indicating normality is output.

[0172] In an embodiment of the present invention, the maximum value of the second threshold voltage range is the first set voltage, and the minimum value thereof is the second set voltage.

[0173] The structure of the fault detection module 1213 is now further described.

[0174] In one implementation, the fault detection signal includes an overcurrent detection signal.

[0175] Please refer to Figure 5 In a specific embodiment, the fault detection module 1213 includes an overcurrent detection unit; the overcurrent detection unit includes a first amplifier 12131 and a detection resistor R sense ;

[0176] The detection resistor R sense A first end of the transistor is coupled to the source of the first MOS transistor M1, and a second end of the transistor is grounded;

[0177] The first input terminal of the first amplifier 12131 is coupled to the detection resistor R sense The first end thereof is coupled to the detection resistor R sense The second end of the device has an output end coupled to the heating control unit 1211 for outputting the overcurrent detection signal.

[0178] In this case, the heating control unit 1211 is configured to:

[0179] Based on the overcurrent detection signal and the overcurrent filtering time, it is determined whether a circuit fault occurs, wherein:

[0180] If the overcurrent detection signal is characterized as abnormal and the duration is greater than the overcurrent filtering time, it is determined that the circuit has an overcurrent and the shutdown drive signal is output.

[0181] The overcurrent filtering time is used to avoid false alarms and ensure the reliability of fault detection.

[0182] In a preferred embodiment, please refer to Figure 6 The heating control unit 1211 is further coupled to a status indicator LED, and the heating control unit 1211 is configured to:

[0183] When overcurrent occurs in the circuit, the status indicator LED is controlled to turn off.

[0184] As an example, the status indicator light may also be an indicator light connected to the fault light driving module 18 , but the present invention is not limited thereto. The status indicator light may also be an indicator light in other peripheral circuits.

[0185] exist Figure 5 In the example, the fault detection signal also includes an open circuit detection signal and a short circuit detection signal.

[0186] The fault detection module 1213 includes an open circuit detection unit, a short circuit detection unit and a voltage setting unit;

[0187] The voltage setting unit includes a second amplifier 12132 and a first switch S1. The first input terminal of the second amplifier 12132 receives the first setting voltage, and the second input terminal of the second amplifier 12132 is coupled to the output terminal of the second amplifier 12132. The output terminal of the second amplifier 12132 is coupled to the first terminal of the first switch S1. The second terminal of the first switch S1 is coupled to the first node.

[0188] The open circuit detection unit includes a third amplifier 12133, wherein a first input terminal of the third amplifier 12133 receives a third set voltage, a second input terminal of the third amplifier 12133 is coupled to the first terminal of the first switch S1, and an output terminal of the third amplifier 12133 is coupled to the heating control unit 1211, wherein the third set voltage is greater than the first set voltage;

[0189] The short circuit detection unit includes a fourth amplifier 12134 , a first input terminal of the fourth amplifier 12134 receives the second set voltage, a second input terminal of the fourth amplifier 12134 is coupled to the first terminal of the first switch S1 , and an output terminal of the fourth amplifier 12134 is coupled to the heating control unit 1211 .

[0190] exist Figure 5 In the example, the first set voltage is 0.5VDD, the second set voltage is 0.4VDD, and the third set voltage is 0.6VDD. The VDD can be understood as the power supply voltage of the engine chip.

[0191] Of course, the present invention is not limited thereto, and those skilled in the art can set the first set voltage, the second set voltage, and the third set voltage as needed.

[0192] On this basis, the voltage of the first node is detected only when the heating control unit 1211 outputs the shutdown driving signal. In one embodiment, please refer to Figure 5 The heating control unit 1211 is further coupled to the control end of the first switch S1, and is configured as follows:

[0193] When the heating control unit 1211 outputs the shutdown driving signal, the first switch S1 is controlled to be turned on.

[0194] In a preferred embodiment, the heating control unit 1211 is further configured to:

[0195] Based on the open circuit detection signal and the open circuit filtering time, it is determined whether a circuit fault occurs, wherein:

[0196] If the open circuit detection signal is abnormal and the duration is greater than the open circuit filtering time, it is determined that the circuit is open circuited and the shutdown drive signal is output; and

[0197] Based on the short-circuit detection signal and the short-circuit filtering time, it is determined whether a circuit fault occurs, wherein:

[0198] If the short-circuit detection signal is abnormal and lasts longer than the short-circuit filtering time, it is determined that a short circuit to ground occurs in the circuit, and the shutdown drive signal is output.

[0199] The open-circuit filtering time and the short-circuit filtering time are used to avoid false alarms and ensure the reliability of fault detection.

[0200] Now combined Figure 7 The waveform of Figure 5 The working principle of the fault detection module 1213 of the present invention is described as follows. Figure 7 FIG1 shows a working waveform diagram of the fault detection module 1213, wherein:

[0201] V_O2Hx, which can be understood as the voltage of the first node;

[0202] I_O2Hx can be understood as the current flowing through the source of the first MOS transistor M1;

[0203] O2Hx can be understood as the actual driving control signal corresponding to the xth oxygen heating module.

[0204] It can be seen that during the time period t1 to t2, the xth oxygen heating module is in a normal working state, the heating control unit 1211 outputs the shutdown drive signal, the voltage of the first node is the system power supply voltage, and the current flowing through the source of the first MOS transistor M1 is the normal diagnostic current;

[0205] During the time period from t2 to t3, the heating control unit 1211 outputs the on-drive signal, and the current flowing through the source of the first MOS transistor M1 increases rapidly and is equal to the first current threshold at time t3, and the x-th oxygen heating module enters an overcurrent fault state;

[0206] During the time period t3 to t4, the xth oxygen heating module is continuously in an overcurrent fault state, and the duration is greater than the overcurrent filtering time, the heating control unit outputs the shutdown drive signal to control the xth oxygen heating module to stop working;

[0207] The time period from t4 to t5 can be understood as the mask time (Tmask time), which is used to ignore the noise signal during the transition period. At this time, the x-th oxygen heating module is in a stopped state, and the voltage of the first node is a clamping voltage. Until the voltage of the first node recovers to the system power supply voltage, the current flowing through the source of the first MOS transistor M1 is a normal diagnostic current.

[0208] During the time period from t5 to t6, the xth oxygen heating module is in a stopped working state, but the voltage of the first node drops to a third set voltage, and the xth oxygen heating module enters an open circuit fault state;

[0209] During the time period from t6 to t7, the xth oxygen heating module is continuously in an open circuit fault state, the voltage of the first node is continuously greater than 0.5 VDD, and the duration is greater than the open circuit filter time, the heating control unit determines that the circuit is in an open circuit fault state, and controls the xth oxygen heating module to stop working;

[0210] During the time period from t7 to t8, the voltage of the first node returns to the normal 0.5 VDD, and drops to 0.4 VDD at time t8, and the x-th oxygen heating module enters a short-circuit fault state to ground;

[0211] During the time period from t8 to t9, the xth oxygen heating module is continuously in a short-circuit fault state to ground, the voltage of the first node is continuously less than 0.4VDD, and the duration is greater than the short-circuit filter time. The heating control unit determines that the circuit is in a short-circuit fault state to ground and controls the xth oxygen heating module to stop working.

[0212] As can be seen from the above content, the fault detection signal in the present invention can inform the heating control unit of specific fault information, so that the heating control unit can output a corresponding drive control signal as needed.

[0213] In summary, the embodiments of the present invention integrate an oxygen heating system within an engine chip, which is electrically connected to a main control chip. The system includes at least two oxygen heating modules, each of which includes: a heating control unit that outputs a drive control signal based on a parallel oxygen heating control signal, a serial oxygen heating control signal, and a fault detection signal; a drive unit that controls the operating state of the corresponding heating element based on the drive control signal; and a fault detection module that performs fault detection on the oxygen heating module. Thus, the present invention integrates multiple oxygen heating modules within the engine chip, enabling the chip to independently heat and detect faults for each oxygen sensor. This reduces peripheral circuitry while improving reliability and reducing complexity.

[0214] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. An oxygen heating system, characterized in that: The oxygen heating system is integrated into the engine chip. The system includes N oxygen heating modules, each of which is used to heat a corresponding oxygen sensor, where N is an integer greater than or equal to 2. The engine chip is electrically connected to the main control chip, and the engine chip includes an SPI module, which is used to receive the SPI control signal sent by the main control chip and output corresponding serial oxygen heating control signals to each oxygen heating module based on the SPI control signal; The main control chip also outputs corresponding parallel oxygen heating control signals to each oxygen heating module; wherein: The oxygen heating module comprises: a heating control unit, receiving the parallel oxygen heating control signal, the serial oxygen heating control signal, and the fault detection signal, and configured to output a drive control signal based on the parallel oxygen heating control signal, the serial oxygen heating control signal, and the fault detection signal; A driving unit, comprising a high-side driver, a clamping sub-unit, and a first MOS transistor, wherein an input end of the high-side driver receives the driving control signal, and an output end thereof is respectively coupled to a first end of the clamping sub-unit and a control end of the first MOS transistor, a second end of the clamping sub-unit and a drain of the first MOS transistor are both coupled to a first node, the first node is further coupled to a first end of a corresponding heating element, and a source of the first MOS transistor is grounded; a fault detection module having a first end coupled to the source of the first MOS transistor, a second end coupled to the first node, and an output end coupled to the heating control unit, for outputting the fault detection signal based on the current flowing through the source of the first MOS transistor and the voltage of the first node.

2. The oxygen heating system according to claim 1, wherein: The drive control signal includes an on-drive signal and an off-drive signal, and outputting a drive control signal based on the parallel oxygen heating control signal, the serial oxygen heating control signal, and the fault detection signal includes: When the parallel oxygen heating control signal is characterized as being on and the serial oxygen heating control signal is characterized as being off, the heating control unit outputs the on drive signal; When the parallel oxygen heating control signal is characterized as being off and the serial oxygen heating control signal is characterized as being on, the heating control unit outputs the on drive signal; When the parallel oxygen heating control signal is characterized as being on and the serial oxygen heating control signal is characterized as being on, the heating control unit outputs the shutoff drive signal; When the parallel oxygen heating control signal is characterized as off and the serial oxygen heating control signal is characterized as off, the heating control unit outputs the off drive signal; When the fault detection signal indicates an abnormality, the heating control unit outputs the shutdown drive signal.

3. The oxygen heating system according to claim 2, wherein: The fault detection module is further configured to: When the heating control unit outputs the turn-on drive signal, outputting the fault detection signal based on the current flowing through the source of the first MOS transistor; When the heating control unit outputs the shutdown driving signal, the failure detection signal is output based on the voltage of the first node.

4. The oxygen heating system according to claim 3, wherein: The method for outputting the fault detection signal based on the current flowing through the source of the first MOS transistor and the voltage of the first node includes: When the heating control unit outputs the turn-on drive signal, if the current flowing through the source of the first MOS transistor is greater than or equal to a first current threshold, outputting the fault detection signal indicating an abnormality; When the heating control unit outputs the on-drive signal, if the current flowing through the source of the first MOS transistor is less than the first current threshold, the fault detection signal indicating normal operation is output; When the heating control unit outputs the shutdown driving signal, if the voltage of the first node does not fall within a second threshold voltage range, outputting the fault detection signal indicating an abnormality; When the heating control unit outputs the shutdown driving signal, if the voltage of the first node falls within the second threshold voltage range, the fault detection signal indicating normality is output.

5. The oxygen heating system according to claim 4, wherein: The fault detection signal includes an overcurrent detection signal, and the fault detection module includes an overcurrent detection unit; the overcurrent detection unit includes a first amplifier and a detection resistor; A first end of the detection resistor is coupled to the source of the first MOS transistor, and a second end thereof is grounded; The first input terminal of the first amplifier is coupled to the first terminal of the detection resistor, the second terminal thereof is coupled to the second terminal of the detection resistor, and the output terminal thereof is coupled to the heating control unit for outputting the overcurrent detection signal.

6. The oxygen heating system according to claim 5, wherein: The heating control unit is configured to determine whether a circuit fault occurs based on the overcurrent detection signal and the overcurrent filtering time, wherein: If the overcurrent detection signal is characterized as abnormal and the duration is greater than the overcurrent filtering time, it is determined that the circuit has an overcurrent and the shutdown drive signal is output.

7. The oxygen heating system according to claim 6, wherein: The heating control unit is further coupled to a status indicator light, and the heating control unit is configured to: When overcurrent occurs in the circuit, the status indicator light is controlled to turn off.

8. The oxygen heating system according to claim 4, wherein: The fault detection signal includes an open circuit detection signal and a short circuit detection signal; the maximum value of the second threshold voltage range is a first set voltage, and the minimum value thereof is a second set voltage; the fault detection module includes an open circuit detection unit, a short circuit detection unit, and a voltage setting unit; The voltage setting unit includes a second amplifier and a first switch, wherein a first input terminal of the second amplifier receives the first setting voltage, a second input terminal of the second amplifier is coupled to an output terminal of the second amplifier, an output terminal of the second amplifier is coupled to a first terminal of the first switch, and a second terminal of the first switch is coupled to the first node; The open circuit detection unit includes a third amplifier, a first input terminal of the third amplifier receives a third set voltage, a second input terminal of the third amplifier is coupled to the first terminal of the first switch, and an output terminal of the third amplifier is coupled to the heating control unit, wherein the third set voltage is greater than the first set voltage; The short circuit detection unit includes a fourth amplifier, a first input terminal of the fourth amplifier receives the second set voltage, a second input terminal of the fourth amplifier is coupled to the first terminal of the first switch, and an output terminal of the fourth amplifier is coupled to the heating control unit.

9. The oxygen heating system according to claim 8, wherein: The heating control unit is further coupled to the control terminal of the first switch, and is configured as follows: When the heating control unit outputs the shutdown driving signal, the first switch is controlled to be turned on.

10. The oxygen heating system according to claim 8, wherein: The heating control unit is configured to determine whether a circuit fault occurs based on the open circuit detection signal and the open circuit filtering time, wherein: If the open circuit detection signal is abnormal and the duration is greater than the open circuit filtering time, it is determined that the circuit is open circuited and the shutdown drive signal is output; and Based on the short-circuit detection signal and the short-circuit filtering time, it is determined whether a circuit fault occurs, wherein: If the short-circuit detection signal is abnormal and lasts longer than the short-circuit filtering time, it is determined that a short circuit to ground occurs in the circuit, and the shutdown drive signal is output.

11. The oxygen heating system according to any one of claims 1 to 10, characterized in that: The engine chip further includes: a power supply module, configured to supply power to the engine chip and a sensor electrically connected to the engine chip; a mode control module, receiving a key signal and configured to control the state of the engine chip to be an operating mode or a standby mode based on the key signal; an injector driving module, coupled to the injector, for driving the injector when the engine chip is in a working mode; a relay driving module, coupled to the relay, for driving the relay when the engine chip is in an operating mode; a speed module, coupled to the tachometer, for outputting a speed signal when the engine chip is in an operating mode; a fault light driving module, coupled to the fault indicator light, for driving the fault indicator light when the system is in a fault state; an idle stepper motor driving module, coupled to the idle stepper motor, and configured to drive the idle stepper motor when the engine chip is in a working mode; a magnetoelectric signal processing module, configured to convert crankshaft magnetoelectric signals when the engine chip is in an operating mode; K-LINE communication module, used to implement OBD communication.

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