Functional safety assessment and detection system and method for electronic circuits of smart kitchen electric heating appliances

Abstract

The present invention discloses a system and method for functional safety assessment of electronic circuits of intelligent kitchen electric heating appliances. The system and method obtain the type and actual coordinates of each circuit element in a circuit board of the tested kitchen electric heating appliance, and then generate a fault injection mode for detecting the circuit board of the tested kitchen electric heating appliance based on the obtained type and actual coordinates. A test plan is formed in combination with the test requirements of users, so that the system can automatically perform functional safety assessment on the circuit board of the tested kitchen electric heating appliance according to the test plan, including: performing weak link fault injection and NTC hardware fault mode injection under different power-on and power-off states and working states of the circuit board of the tested kitchen electric heating appliance; therefore, the present invention realizes the automated test of functional safety assessment of electronic circuits of intelligent kitchen electric heating appliances, and has the advantages of high test efficiency, high reliability, high accuracy, strong repeatability and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of functional safety assessment and detection of kitchen electric heating appliances, and in particular to a system and method for functional safety assessment and detection of electronic circuits of intelligent kitchen electric heating appliances. Background Art

[0002] With the rapid advancement of science and technology, the hardware circuit design of various home appliances has become increasingly complex, greatly enriching the functions and design methods of various home appliances, but also increasing the complexity of product safety and reliability evaluation. In particular, the stability and durability of the hardware circuit as the core of the appliance control are crucial to the operation of the entire product, and are directly related to the user experience and the safety of life and property.

[0003] At present, the detection and evaluation of hardware circuit safety and reliability is an important part of ensuring product safety. According to the current evaluation standards, testing agencies usually use artificial simulation of electronic circuit failures for testing. The main method is to manually implement the failure in a non-working state, and then enter the working state to test the impact of the failure. This method is inefficient, costly, and the failure consideration is relatively one-sided, and it cannot fully cover the occurrence of electronic circuit failures. In addition, due to the limitations of manual operation, the current test efficiency and test results are easily affected by the proficiency of manual operation. With the continuous development of electronic technology and computer technology, automated detection solutions have gradually emerged to improve detection efficiency and accuracy.

[0004] At present, most of the research and development on hardware circuit fault simulation detection in the industry are concentrated on specific application areas (such as automobiles, smart meters, integrated circuit design, etc.) or specific problems (such as fault diagnosis and troubleshooting, circuit fault simulation, etc.).

[0005] Currently, there are many technical solutions in the field of hardware fault detection and evaluation, but most of these solutions focus on specific industry applications or solutions to specific problems, such as the automotive industry, integrated circuit design industry, etc., as well as circuit fault diagnosis, fault simulation, etc., and do not fully consider the rich and diverse hardware circuit fault conditions of smart kitchen heating household appliances, and cannot be applied to the complex fault action monitoring of household appliances. Therefore, there is still a gap in the detection and evaluation of hardware circuit safety of smart kitchen heating household appliances. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a system and method for evaluating the functional safety of electronic circuits of intelligent kitchen electric heating appliances.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] A functional safety assessment and detection system for electronic circuits of intelligent kitchen electric heating appliances, which is applicable to the circuit board of the kitchen electric heating appliance under test with a thermistor detection device, is characterized in that it comprises: a host computer, a hardware fault injection unit, a product data monitoring unit and a product control unit;

[0009] The hardware fault injection unit is provided with an image acquisition module, a mechanical arm, a mechanical wiring device and an NTC hardware fault injection module; the image acquisition module can take a picture of the circuit board of the kitchen electric heating appliance under test to obtain the picture of the circuit board under test and transmit it to the host computer, and preferably adopts a wireless network to transmit the picture of the circuit board under test; the mechanical arm can move the wiring end of the mechanical wiring device under the control of the host computer; when the wiring end moves to a corresponding position, the mechanical wiring device can realize the electrical connection between any plurality of circuit element pins in the circuit board of the kitchen electric heating appliance under test, or realize the electrical connection between the thermistor port of the circuit board of the kitchen electric heating appliance under test and any fault port of the NTC hardware fault injection module;

[0010] The product control unit can set the power on / off state and working state of the circuit board of the tested kitchen electric heating appliance under the control of the host computer;

[0011] The product data monitoring unit can monitor various working status data of the circuit board of the kitchen electric heating appliance under test and transmit them to the host computer; wherein, the product data monitoring unit is connected to the host computer through a dedicated interface, and the product data monitoring unit generally includes a temperature sensor, a digital power meter, a buzzer detection device, etc., and each sensor of the product data monitoring unit is respectively connected to the corresponding status feedback port of the circuit board of the kitchen electric heating appliance under test.

[0012] Preferred: See Figure 2 The robotic arm grabs the electrical connection cable as the mechanical wiring device, and respectively contacts the two exposed wiring ends of the electrical connection cable with the corresponding circuit element pins in the circuit board of the kitchen electric heating appliance under test, so that the corresponding circuit element pins are disconnected, so as to realize the fault injection into the weak link of the circuit board of the kitchen electric heating appliance under test.

[0013] Preferred: See Figure 2 and Figure 3 , the NTC hardware fault injection module is provided with a fault injection controller U1, a resistance constant fault injection circuit, a short circuit fault injection circuit and a reset circuit;

[0014] The resistance-invariant fault injection circuit is provided with a first isolating switch circuit K1, a sliding rheostat RP1 and a resistance-invariant fault port J1, wherein the switch port of the first isolating switch circuit K1, the sliding rheostat RP1 and the resistance-invariant fault port J1 are connected in series;

[0015] The short-circuit fault injection circuit is provided with a second isolating switch circuit K2 and a short-circuit fault port J2, and the switch port of the second isolating switch circuit K2 and the short-circuit fault port J2 are connected in series;

[0016] The reset circuit is provided with a third isolation switch circuit K3, a thermistor NTC and a reset fault port J3, and the switch port of the third isolation switch circuit K3, the thermistor NTC and the reset fault port J3 are connected in series;

[0017] The fault injection controller U1 can receive control instructions from the host computer to control the on and off of the switch ports of the first isolation switch circuit K1, the second isolation switch circuit K2 and the third isolation switch circuit K3 respectively;

[0018] The robotic arm can move the wiring end of the mechanical wiring device to a corresponding position so that the mechanical wiring device can realize electrical connection between the thermistor port of the circuit board of the tested kitchen electric heating appliance and any one of the resistance unchanged fault port J1, the short circuit fault port J2 and the reset fault port J3 of the NTC hardware fault injection module; wherein the mechanical wiring device can be one or more electrical connection cables.

[0019] Preferred: See Figure 3 The circuit structures of the first isolating switch circuit K1, the second isolating switch circuit K2 and the third isolating switch circuit K3 are:

[0020] The base of the transistor is connected to the fault injection controller U1 as a control terminal, and the base of the transistor is connected to one end of the first resistor and the cathode of the freewheeling diode, the other end of the first resistor is connected to the DC power supply VCC2 and the emitter of the transistor, the anode of the freewheeling diode and the cathode of the photocoupler are both connected to the ground terminal GND, and the collector of the transistor is connected to the anode of the photocoupler through the second resistor; the collector and emitter of the photocoupler serve as switch ports. Therefore, the fault injection controller U1 can control the transistor to conduct by providing a low-level signal to the base of the transistor, so that the collector and emitter of the photocoupler serving as the switch port are conducted.

[0021] Among them, transistor Q1, resistor R9, freewheeling diode D3, photocoupler GD1, and resistor R10 constitute a first isolation switch circuit K1; transistor Q2, resistor R7, freewheeling diode D2, photocoupler GD2, and resistor R6 constitute a second isolation switch circuit K2; transistor Q3, resistor R5, freewheeling diode D1, photocoupler GD3, and resistor R4 constitute a third isolation switch circuit K3.

[0022] like Figures 1 to 4As shown, a method for functional safety assessment and detection of electronic circuits of intelligent kitchen electric heating appliances is characterized by: being implemented based on the functional safety assessment and detection system of electronic circuits of intelligent kitchen electric heating appliances;

[0023] include:

[0024] Step S1, importing the circuit board silk screen image of the circuit board of the kitchen electric heating appliance to be tested into the host computer;

[0025] Step S2, placing the circuit board of the kitchen electric heating appliance under test horizontally at a preset test position, and taking a picture of the circuit board of the kitchen electric heating appliance under test by using an image acquisition module of a host computer;

[0026] Step S3, the host computer identifies the circuit component features in the tested circuit board image obtained in step S2 by image recognition technology, and matches them with the known component types in the circuit board silk screen image obtained in step S1, so as to calibrate the type and image coordinates of each circuit component in the tested circuit board image, and convert them into the type and actual coordinates of each circuit component in the tested kitchen electric heating appliance circuit board;

[0027] Step S4, generating a fault injection mode capable of detecting the circuit board of the tested kitchen electric heating appliance according to the preset rules and the type and actual coordinates of the circuit element obtained in step S3, wherein each fault injection mode includes a corresponding fault injection coordinate determined by the actual coordinates obtained in step S3;

[0028] Step S5, through the host computer, select the fault injection mode to be executed from the fault injection modes obtained in step S4, and set: the execution order of various fault injection modes, the execution time and number of each fault injection mode, the power-on and power-off state and working state of the circuit board of the tested kitchen electric heating appliance in each fault injection mode; thereby, a test plan is formed;

[0029] Step S6, start executing the test plan formed in step S5;

[0030] Among them, during the test:

[0031] The host computer controls the mechanical arm to move the wiring end of the mechanical wiring device to a corresponding position, so that the mechanical wiring device realizes electrical connection between the pins of multiple circuit elements in the circuit board of the kitchen electric heating appliance under test, so as to realize fault injection into the weak link of the circuit board of the kitchen electric heating appliance under test;

[0032] The host computer controls the mechanical arm to move the wiring end of the mechanical wiring device to a corresponding position, so that the mechanical wiring device realizes electrical connection between the thermistor port of the circuit board of the kitchen electric heating appliance under test and any fault port of the NTC hardware fault injection module, so as to realize the NTC hardware fault injection module injection of the thermistor of the circuit board of the kitchen electric heating appliance under test;

[0033] The host computer is connected to the power supply circuit and the control circuit of the circuit board of the kitchen electric heating appliance under test respectively through the product control unit, so as to respectively set the power on and off state and the working state of the circuit board of the kitchen electric heating appliance under test, and can reset the circuit board of the kitchen electric heating appliance under test when an error is reported;

[0034] The host computer collects the working status data of the circuit board of the tested kitchen electric heating appliance at set time intervals through the product data monitoring unit.

[0035] Preferably: the smart kitchen electric heating appliance electronic circuit functional safety assessment and detection method further includes:

[0036] Step S7: After completing the test plan started in step S6, the host computer extracts the data during the test to form a test report.

[0037] Preferably, in step S4, the fault injection method includes a weak link fault injection method, and the preset rules for generating the weak link fault injection method include:

[0038] Rule 1: If the electrical clearance or creepage distance between two circuit elements is less than the corresponding preset minimum value, the fault injection is achieved by short-circuiting the functional insulation of the two circuit elements;

[0039] Rule 2: If the circuit element is a chip capacitor or a chip resistor, the fault injection is achieved by short-circuiting the circuit element;

[0040] Rule 3: If the circuit element is a non-integrated circuit electronic element, the fault injection is achieved by short-circuiting any two terminals of the circuit element;

[0041] Rule 4: If the circuit element is a triac, the fault injection is achieved by connecting the circuit element to a diode;

[0042] Rule 5: If the circuit element is an MCU chip, fault injection is achieved by connecting any pin of the circuit element to the GND pin and the VDD pin respectively to pull up and down the voltage.

[0043] Preferably, in step S4, the fault injection method includes an NTC hardware fault mode injection method, and the preset rule for generating the NTC hardware fault mode injection method is:

[0044] By adjusting the resistance of the sliding rheostat RP1, electrically connecting the resistance-invariant fault port J1 of the NTC hardware fault injection module to the thermistor port of the circuit board of the kitchen electric heating appliance under test, and controlling the switch port of the first isolation switch circuit K1 to be turned on by the fault injection controller U1, the NTC fixed resistance fault injection of the circuit board of the kitchen electric heating appliance under test is realized;

[0045] By electrically connecting the short-circuit fault port J2 of the NTC hardware fault injection module to the thermistor port of the circuit board of the kitchen electric heating appliance under test, and controlling the switch port of the second isolation switch circuit K2 to be turned on by the fault injection controller U1, the NTC short-circuit fault injection to the circuit board of the kitchen electric heating appliance under test is achieved;

[0046] By electrically connecting the reset fault port J3 of the NTC hardware fault injection module to the thermistor port of the circuit board of the kitchen electric heating appliance under test, and controlling the switch port of the third isolation switch circuit K3 to be turned on by the fault injection controller U1, the NTC fault circuit of the circuit board of the kitchen electric heating appliance under test is reset to solve the scenario of implementing multiple tests for one fault test. After the previous fault injection test is completed, the NTC fault circuit is reset before the next fault injection test is carried out.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] First, the present invention is implemented based on the functional safety assessment and detection system of the electronic circuit of the intelligent kitchen electric heating appliance. By obtaining the type and actual coordinates of each circuit element in the circuit board of the tested kitchen electric heating appliance, a fault injection mode that can be detected by the circuit board of the tested kitchen electric heating appliance is generated based on the obtained type and actual coordinates, thereby forming a test plan in combination with the test requirements of the user, so that the functional safety assessment and detection system of the electronic circuit of the intelligent kitchen electric heating appliance can automatically perform functional safety assessment and detection on the circuit board of the tested kitchen electric heating appliance according to the test plan, including: in different power-on and power-off states and working states of the circuit board of the tested kitchen electric heating appliance, weak link fault injection and NTC hardware fault model injection are performed to simulate different abnormal conditions of the circuit elements of the circuit board in the non-working state and the working state for a long time, automatically and efficiently, and repeatedly, and then the working state data of the circuit board of the tested kitchen electric heating appliance is automatically collected in a long period of time during the test process through the product data monitoring unit, so as to evaluate the processing ability of the electronic circuit to potential hardware fault risks and the execution ability of corresponding safety measures; therefore, the present invention realizes the automated test of the functional safety assessment of the electronic circuit of the intelligent kitchen electric heating appliance, and has the advantages of high test efficiency, high reliability, high accuracy, strong repeatability and low cost.

[0049] Second, the fault injection method of the present invention includes a weak link fault injection method and an NTC hardware fault model injection method, which can fully simulate the situations that the circuit board of the tested kitchen electric heating appliance may encounter in actual operation, and realize comprehensive fault simulation of the equipment at different operation stages.

[0050] Third, the present invention uses visual technology to achieve high-precision fault location, takes pictures with a camera and identifies circuit board components, and based on image processing, ensures extremely high accuracy of fault location. In addition, the robot arm is responsible for performing specific fault injection operations, such as simulating short circuits, and this process does not require human intervention, greatly improving the test efficiency and accuracy. This combination of technologies not only overcomes the shortcomings of inaccurate positioning and cumbersome operations in traditional fault injection methods, but also promotes the development of circuit fault injection test technology towards intelligence and automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0052] Figure 1 It is a circuit principle block diagram of the electronic circuit functional safety assessment and detection system of the intelligent kitchen electric heating appliance of the present invention;

[0053] Figure 2 It is a schematic diagram of the present invention performing fault injection on a circuit board of a kitchen electric heating appliance under test;

[0054] Figure 3 It is a circuit schematic diagram of the NTC hardware fault injection module in the present invention;

[0055] Figure 4 The present invention is a flow chart of the method for evaluating the functional safety of electronic circuits of smart kitchen electric heating appliances. DETAILED DESCRIPTION

[0056] The present invention is described in detail below in conjunction with the embodiments and the accompanying drawings to help those skilled in the art better understand the inventive concept of the present invention. However, the protection scope of the claims of the present invention is not limited to the following embodiments. For those skilled in the art, all other embodiments obtained without creative work without departing from the inventive concept of the present invention belong to the protection scope of the present invention.

[0057] Embodiment 1

[0058] like Figure 1 As shown, the present invention discloses a functional safety assessment and detection system for electronic circuits of intelligent kitchen electric heating appliances, which is applicable to the circuit board of the kitchen electric heating appliance under test with a thermistor detection device, and includes: a host computer, a hardware fault injection unit, a product data monitoring unit and a product control unit;

[0059] The hardware fault injection unit is provided with an image acquisition module, a mechanical arm, a mechanical wiring device and an NTC hardware fault injection module; the image acquisition module can take a picture of the circuit board of the kitchen electric heating appliance under test to obtain the picture of the circuit board under test and transmit it to the host computer, and preferably adopts a wireless network to transmit the picture of the circuit board under test; the mechanical arm can move the wiring end of the mechanical wiring device under the control of the host computer; when the wiring end moves to a corresponding position, the mechanical wiring device can realize the electrical connection between any plurality of circuit element pins in the circuit board of the kitchen electric heating appliance under test, or realize the electrical connection between the thermistor port of the circuit board of the kitchen electric heating appliance under test and any fault port of the NTC hardware fault injection module;

[0060] The product control unit can set the power on / off state and working state of the circuit board of the tested kitchen electric heating appliance under the control of the host computer;

[0061] The product data monitoring unit can monitor various working status data of the circuit board of the kitchen electric heating appliance under test and transmit them to the host computer; wherein, the product data monitoring unit is connected to the host computer through a dedicated interface, and the product data monitoring unit generally includes a temperature sensor, a digital power meter, a buzzer detection device, etc., and each sensor of the product data monitoring unit is respectively connected to the corresponding status feedback port of the circuit board of the kitchen electric heating appliance under test.

[0062] The above is a basic implementation of the first embodiment of the present invention, and further optimization, improvement and limitation can be made on the basis of the basic implementation:

[0063] Preferred: See Figure 2 The robotic arm grabs the electrical connection cable as the mechanical wiring device, and respectively contacts the two exposed wiring ends of the electrical connection cable with the corresponding circuit element pins in the circuit board of the kitchen electric heating appliance under test, so that the corresponding circuit element pins are disconnected, so as to realize the fault injection into the weak link of the circuit board of the kitchen electric heating appliance under test.

[0064] Preferred: See Figure 2 and Figure 3 , the NTC hardware fault injection module is provided with a fault injection controller U1, a resistance constant fault injection circuit, a short circuit fault injection circuit and a reset circuit;

[0065] The resistance-invariant fault injection circuit is provided with a first isolating switch circuit K1, a sliding rheostat RP1 and a resistance-invariant fault port J1, wherein the switch port of the first isolating switch circuit K1, the sliding rheostat RP1 and the resistance-invariant fault port J1 are connected in series;

[0066] The short-circuit fault injection circuit is provided with a second isolating switch circuit K2 and a short-circuit fault port J2, and the switch port of the second isolating switch circuit K2 and the short-circuit fault port J2 are connected in series;

[0067] The reset circuit is provided with a third isolation switch circuit K3, a thermistor NTC and a reset fault port J3, and the switch port of the third isolation switch circuit K3, the thermistor NTC and the reset fault port J3 are connected in series;

[0068] The fault injection controller U1 can receive control instructions from the host computer to control the on and off of the switch ports of the first isolation switch circuit K1, the second isolation switch circuit K2 and the third isolation switch circuit K3 respectively;

[0069] The robotic arm can move the wiring end of the mechanical wiring device to a corresponding position so that the mechanical wiring device can realize electrical connection between the thermistor port of the circuit board of the tested kitchen electric heating appliance and any one of the resistance unchanged fault port J1, the short circuit fault port J2 and the reset fault port J3 of the NTC hardware fault injection module; wherein the mechanical wiring device can be one or more electrical connection cables.

[0070] Preferred: See Figure 3 The circuit structures of the first isolating switch circuit K1, the second isolating switch circuit K2 and the third isolating switch circuit K3 are:

[0071] The base of the transistor is connected to the fault injection controller U1 as a control terminal, and the base of the transistor is connected to one end of the first resistor and the cathode of the freewheeling diode, the other end of the first resistor is connected to the DC power supply VCC2 and the emitter of the transistor, the anode of the freewheeling diode and the cathode of the photocoupler are both connected to the ground terminal GND, and the collector of the transistor is connected to the anode of the photocoupler through the second resistor; the collector and emitter of the photocoupler serve as switch ports. Therefore, the fault injection controller U1 can control the transistor to conduct by providing a low-level signal to the base of the transistor, so that the collector and emitter of the photocoupler serving as the switch port are conducted.

[0072] Among them, transistor Q1, resistor R9, freewheeling diode D3, photocoupler GD1, and resistor R10 constitute a first isolation switch circuit K1; transistor Q2, resistor R7, freewheeling diode D2, photocoupler GD2, and resistor R6 constitute a second isolation switch circuit K2; transistor Q3, resistor R5, freewheeling diode D1, photocoupler GD3, and resistor R4 constitute a third isolation switch circuit K3.

[0073] Embodiment 2

[0074] like Figures 1 to 4As shown, the present invention also discloses a method for evaluating and detecting the functional safety of electronic circuits of smart kitchen electric heating appliances, which is characterized by: implementing the method based on the functional safety evaluation and detection system for electronic circuits of smart kitchen electric heating appliances described in Embodiment 1;

[0075] include:

[0076] Step S1, importing the circuit board silk screen image of the circuit board of the kitchen electric heating appliance to be tested into the host computer;

[0077] Step S2, placing the circuit board of the kitchen electric heating appliance under test horizontally at a preset test position, and taking a picture of the circuit board of the kitchen electric heating appliance under test by using an image acquisition module of a host computer;

[0078] Step S3, the host computer identifies the circuit component features in the tested circuit board image obtained in step S2 by image recognition technology, and matches them with the known component types in the circuit board silk screen image obtained in step S1, so as to calibrate the type and image coordinates of each circuit component in the tested circuit board image, and convert them into the type and actual coordinates of each circuit component in the tested kitchen electric heating appliance circuit board;

[0079] Step S4, generating a fault injection mode capable of detecting the circuit board of the tested kitchen electric heating appliance according to the preset rules and the type and actual coordinates of the circuit element obtained in step S3, wherein each fault injection mode includes a corresponding fault injection coordinate determined by the actual coordinates obtained in step S3;

[0080] Step S5, through the host computer, select the fault injection mode to be executed from the fault injection modes obtained in step S4, and set: the execution order of various fault injection modes, the execution time and number of each fault injection mode, the power-on and power-off state and working state of the circuit board of the tested kitchen electric heating appliance in each fault injection mode; thereby, a test plan is formed;

[0081] Step S6, start executing the test plan formed in step S5;

[0082] Among them, during the test:

[0083] The host computer controls the mechanical arm to move the wiring end of the mechanical wiring device to a corresponding position, so that the mechanical wiring device realizes electrical connection between the pins of multiple circuit elements in the circuit board of the kitchen electric heating appliance under test, so as to realize fault injection into the weak link of the circuit board of the kitchen electric heating appliance under test;

[0084] The host computer controls the mechanical arm to move the wiring end of the mechanical wiring device to a corresponding position, so that the mechanical wiring device realizes electrical connection between the thermistor port of the circuit board of the kitchen electric heating appliance under test and any fault port of the NTC hardware fault injection module, so as to realize the NTC hardware fault injection module injection of the thermistor of the circuit board of the kitchen electric heating appliance under test;

[0085] The host computer is connected to the power supply circuit and the control circuit of the circuit board of the kitchen electric heating appliance under test respectively through the product control unit, so as to respectively set the power on and off state and the working state of the circuit board of the kitchen electric heating appliance under test, and can reset the circuit board of the kitchen electric heating appliance under test when an error is reported;

[0086] The host computer collects the working status data of the circuit board of the tested kitchen electric heating appliance at set time intervals through the product data monitoring unit.

[0087] The above is a basic implementation of the second embodiment, and further optimization, improvement and limitation can be made on the basis of the basic implementation:

[0088] Preferably: the smart kitchen electric heating appliance electronic circuit functional safety assessment and detection method further includes:

[0089] Step S7: After completing the test plan started in step S6, the host computer extracts the data during the test to form a test report.

[0090] Preferably, in step S4, the fault injection method includes a weak link fault injection method, and the preset rules for generating the weak link fault injection method include:

[0091] Rule 1: If the electrical clearance or creepage distance between two circuit elements is less than the corresponding preset minimum value, the fault injection is achieved by short-circuiting the functional insulation of the two circuit elements;

[0092] Rule 2: If the circuit element is a chip capacitor or a chip resistor, the fault injection is achieved by short-circuiting the circuit element;

[0093] Rule 3: If the circuit element is a non-integrated circuit electronic element, the fault injection is achieved by short-circuiting any two terminals of the circuit element;

[0094] Rule 4: If the circuit element is a triac, the fault injection is achieved by connecting the circuit element to a diode;

[0095] Rule 5: If the circuit element is an MCU chip, fault injection is achieved by connecting any pin of the circuit element to the GND pin and the VDD pin respectively to pull up and down the voltage.

[0096] Preferably, in step S4, the fault injection method includes an NTC hardware fault mode injection method, and the preset rule for generating the NTC hardware fault mode injection method is:

[0097] By adjusting the resistance of the sliding rheostat RP1, electrically connecting the resistance-invariant fault port J1 of the NTC hardware fault injection module to the thermistor port of the circuit board of the kitchen electric heating appliance under test, and controlling the switch port of the first isolation switch circuit K1 to be turned on by the fault injection controller U1, the NTC fixed resistance fault injection of the circuit board of the kitchen electric heating appliance under test is realized;

[0098] By electrically connecting the short-circuit fault port J2 of the NTC hardware fault injection module to the thermistor port of the circuit board of the kitchen electric heating appliance under test, and controlling the switch port of the second isolation switch circuit K2 to be turned on by the fault injection controller U1, the NTC short-circuit fault injection to the circuit board of the kitchen electric heating appliance under test is achieved;

[0099] By electrically connecting the reset fault port J3 of the NTC hardware fault injection module to the thermistor port of the circuit board of the kitchen electric heating appliance under test, and controlling the switch port of the third isolation switch circuit K3 to be turned on by the fault injection controller U1, the NTC fault circuit of the circuit board of the kitchen electric heating appliance under test is reset to solve the scenario of implementing multiple tests for one fault test. After the previous fault injection test is completed, the NTC fault circuit is reset before the next fault injection test is carried out.

[0100] The present invention is not limited to the above-mentioned specific implementation modes. According to the above-mentioned contents, in accordance with the common technical knowledge and customary means in the field, without departing from the above-mentioned basic technical ideas of the present invention, the present invention can also make other various forms of equivalent modifications, replacements or changes, all of which fall within the protection scope of the present invention.

Claims

1. A functional safety assessment and detection system for electronic circuits of intelligent kitchen electric heating appliances, suitable for the circuit board of the kitchen electric heating appliance under test with a thermistor detection device, characterized in that: include: Host computer, hardware fault injection unit, product data monitoring unit and product control unit; The hardware fault injection unit is provided with an image acquisition module, a mechanical arm, a mechanical wiring device and an NTC hardware fault injection module; the image acquisition module can take a picture of the circuit board of the kitchen electric heating appliance under test to obtain the picture of the circuit board under test and transmit it to the host computer; the mechanical arm can move the wiring end of the mechanical wiring device under the control of the host computer; when the wiring end moves to a corresponding position, the mechanical wiring device can realize the electrical connection between any plurality of circuit element pins in the circuit board of the kitchen electric heating appliance under test, or realize the electrical connection between the thermistor port of the circuit board of the kitchen electric heating appliance under test and any fault port of the NTC hardware fault injection module; The product control unit can set the power on / off state and working state of the circuit board of the tested kitchen electric heating appliance under the control of the host computer; The product data monitoring unit can monitor various working status data of the circuit board of the kitchen electric heating appliance under test and transmit the data to the host computer.

2. According to claim 1, the electronic circuit functional safety assessment and detection system for intelligent kitchen electric heating appliances is characterized by: The robotic arm grabs the electrical connection cable as the mechanical wiring device, and respectively contacts the two exposed wiring ends of the electrical connection cable with the corresponding circuit element pins in the circuit board of the kitchen electric heating appliance under test, so that the corresponding circuit element pins are disconnected, thereby realizing fault injection into the weak link of the circuit board of the kitchen electric heating appliance under test.

3. The intelligent kitchen electric heating appliance electronic circuit functional safety assessment and detection system according to claim 1 or 2, characterized in that: The NTC hardware fault injection module is provided with a fault injection controller (U1), a resistance constant fault injection circuit, a short circuit fault injection circuit and a reset circuit; The resistance-unchanged fault injection circuit is provided with a first isolating switch circuit (K1), a sliding rheostat (RP1) and a resistance-unchanged fault port (J1), wherein the switch port of the first isolating switch circuit (K1), the sliding rheostat (RP1) and the resistance-unchanged fault port (J1) are connected in series; The short-circuit fault injection circuit is provided with a second isolating switch circuit (K2) and a short-circuit fault port (J2), and the switch port of the second isolating switch circuit (K2) and the short-circuit fault port (J2) are connected in series; The reset circuit is provided with a third isolating switch circuit (K3), a thermistor (NTC) and a reset fault port (J3), and the switch port of the third isolating switch circuit (K3), the thermistor (NTC) and the reset fault port (J3) are connected in series; The fault injection controller (U1) is capable of receiving control instructions from a host computer and controlling the on and off of switch ports of the first isolating switch circuit (K1), the second isolating switch circuit (K2) and the third isolating switch circuit (K3); The mechanical arm can move the wiring end of the mechanical wiring device to a corresponding position, so that the mechanical wiring device realizes electrical connection between the thermistor port of the circuit board of the kitchen electric heating appliance under test and any one of the resistance unchanged fault port (J1), the short circuit fault port (J2) and the reset fault port (J3) of the NTC hardware fault injection module.

4. According to claim 3, the electronic circuit functional safety assessment and detection system for intelligent kitchen electric heating appliances is characterized in that: The circuit structures of the first isolating switch circuit (K1), the second isolating switch circuit (K2) and the third isolating switch circuit (K3) are: The base of the transistor is connected to the fault injection controller (U1) as a control end, and the base of the transistor is connected to one end of a first resistor and a cathode of a freewheeling diode, the other end of the first resistor is connected to a DC power supply (VCC2) and an emitter of the transistor, the anode of the freewheeling diode and the cathode of the photoelectric coupler are both connected to a ground terminal (GND), and the collector of the transistor is connected to the anode of the photoelectric coupler through a second resistor; the collector and emitter of the photoelectric coupler serve as switch ports.

5. A method for functional safety assessment of electronic circuits of smart kitchen electric heating appliances, characterized in that: Implementation based on the electronic circuit functional safety assessment and detection system of the smart kitchen electric heating appliance according to any one of claims 1 to 4; include: Step S1, importing the circuit board silk screen image of the circuit board of the kitchen electric heating appliance to be tested into the host computer; Step S2, placing the circuit board of the kitchen electric heating appliance under test horizontally at a preset test position, and taking a picture of the circuit board of the kitchen electric heating appliance under test by using an image acquisition module of a host computer; Step S3, the host computer identifies the circuit component features in the tested circuit board image obtained in step S2 by image recognition technology, and matches them with the known component types in the circuit board silk screen image obtained in step S1, so as to calibrate the type and image coordinates of each circuit component in the tested circuit board image, and convert them into the type and actual coordinates of each circuit component in the tested kitchen electric heating appliance circuit board; Step S4, generating a fault injection mode capable of detecting the circuit board of the tested kitchen electric heating appliance according to the preset rules and the type and actual coordinates of the circuit element obtained in step S3, wherein each fault injection mode includes a corresponding fault injection coordinate determined by the actual coordinates obtained in step S3; Step S5, through the host computer, select the fault injection mode to be executed from the fault injection modes obtained in step S4, and set: the execution order of various fault injection modes, the execution time and number of each fault injection mode, the power-on and power-off state and working state of the circuit board of the tested kitchen electric heating appliance in each fault injection mode; thereby, a test plan is formed; Step S6, start executing the test plan formed in step S5; Among them, during the test: The host computer controls the mechanical arm to move the wiring end of the mechanical wiring device to a corresponding position, so that the mechanical wiring device realizes electrical connection between the pins of multiple circuit elements in the circuit board of the kitchen electric heating appliance under test, so as to realize fault injection into the weak link of the circuit board of the kitchen electric heating appliance under test; The host computer controls the mechanical arm to move the wiring end of the mechanical wiring device to a corresponding position, so that the mechanical wiring device realizes electrical connection between the thermistor port of the circuit board of the kitchen electric heating appliance under test and any fault port of the NTC hardware fault injection module, so as to realize the NTC hardware fault injection module injection of the thermistor of the circuit board of the kitchen electric heating appliance under test; The host computer is connected to the power supply circuit and the control circuit of the circuit board of the kitchen electric heating appliance under test respectively through the product control unit to respectively set the power on / off state and the working state of the circuit board of the kitchen electric heating appliance under test; The host computer collects the working status data of the circuit board of the tested kitchen electric heating appliance at set time intervals through the product data monitoring unit.

6. The method for functional safety assessment of electronic circuits of smart kitchen electric heating appliances according to claim 5 is characterized in that: The functional safety assessment and detection method for the electronic circuit of the smart kitchen electric heating appliance also includes: Step S7: After completing the test plan started in step S6, the host computer extracts the data during the test to form a test report.

7. The method for functional safety assessment of electronic circuits of smart kitchen electric heating appliances according to claim 5 or 6, characterized in that: In step S4, the fault injection method includes a weak link fault injection method, and the preset rules for generating the weak link fault injection method include: Rule 1: If the electrical clearance or creepage distance between two circuit elements is less than the corresponding preset minimum value, the fault injection is achieved by short-circuiting the functional insulation of the two circuit elements; Rule 2: If the circuit element is a chip capacitor or a chip resistor, the fault injection is achieved by short-circuiting the circuit element; Rule 3: If the circuit element is a non-integrated circuit electronic element, the fault injection is achieved by short-circuiting any two terminals of the circuit element; Rule 4: If the circuit element is a triac, the fault injection is achieved by connecting the circuit element to a diode; Rule 5: If the circuit element is an MCU chip, fault injection is achieved by connecting any pin of the circuit element to the GND pin and the VDD pin respectively to pull up and down the voltage.

8. The method for functional safety assessment of electronic circuits of smart kitchen electric heating appliances according to claim 5 or 6, characterized in that: In step S4, the fault injection method includes an NTC hardware fault mode injection method, and the preset rule for generating the NTC hardware fault mode injection method is: By adjusting the resistance of a sliding rheostat (RP1), electrically connecting a resistance-invariant fault port (J1) of an NTC hardware fault injection module to a thermistor port of a circuit board of a kitchen electric heating appliance under test, and controlling the switching port of a first isolation switch circuit (K1) to be turned on through a fault injection controller (U1), an NTC fixed resistance fault injection into the circuit board of the kitchen electric heating appliance under test is achieved; By electrically connecting the short-circuit fault port (J2) of the NTC hardware fault injection module to the thermistor port of the circuit board of the kitchen electric heating appliance under test, and controlling the switch port of the second isolation switch circuit (K2) to be turned on through the fault injection controller (U1), the NTC short-circuit fault injection into the circuit board of the kitchen electric heating appliance under test is achieved; The NTC fault circuit of the kitchen electric heating appliance circuit board under test is reset by electrically connecting the reset fault port (J3) of the NTC hardware fault injection module to the thermistor port of the circuit board of the kitchen electric heating appliance under test, and controlling the switch port of the third isolation switch circuit (K3) to be turned on by the fault injection controller (U1).

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