A CAN bus lighting control method for forklift

Abstract

The invention discloses a CAN bus lighting control method for a forklift, and relates to the technical field of forklift lighting control. The invention constructs a historical evaluation database, takes historical overcurrent faults and overheating faults as reference data, analyzes an overcurrent evaluation set and an overheating evaluation set in a set time window before the fault occurs as reference data, collects the current value and temperature value of a mosfet output module in real time, calculates the overcurrent evaluation set and the overheating evaluation set, compares the current trend index with the historical data to calculate the similarity index ratio, screens out similar reference sets, and further determines the degree of similarity by calculating the Euclidean distance. When the Euclidean distance is lower than the set reference distance value, a corresponding overcurrent or overheating early warning signal is triggered, and the most similar reference historical fault can be found, thereby providing a clear direction and detailed reference information for technicians to trace the root cause of the fault, facilitating the maintenance and troubleshooting of the forklift, and reducing the maintenance cost and downtime.

Description

Technical Field

[0001] The invention relates to the technical field of forklift lighting control, in particular to a CAN bus lighting control method for a forklift. Background Art

[0002] In the existing forklift lighting control field, there are mainly two common methods: first, directly control the on and off of the lights through various function switches; second, use the function switch to control the relay, and use the closing and opening of the relay contacts to achieve the turning on and off of the lights.

[0003] However, both of the above methods have significant disadvantages:

[0004] In the process of mechanical contact control, the sudden current change caused by the closing and opening of the contacts will generate arcs, causing contact erosion. When the load current is large and the contact is working for a long time, heat will accumulate due to the contact resistance between the contacts, causing the switch and relay structural parts to deform, and eventually causing the contacts to fail to conduct normally or increase the conduction resistance;

[0005] In addition, traditional control methods make it difficult to achieve centralized monitoring and management of lighting systems, and lack effective protection against abnormal conditions such as overcurrent and overheating, which can easily lead to damage to lamps and circuits. Once a fault occurs, troubleshooting and repair work is time-consuming and labor-intensive, increasing the maintenance cost and downtime of the forklift.

[0006] Therefore, a CAN bus lighting control method for forklift is introduced. Summary of the invention

[0007] The purpose of the present invention is to solve the problems mentioned in the background technology and to provide a CAN bus lighting control method for a forklift.

[0008] The purpose of the present invention can be achieved through the following technical solutions: A CAN bus lighting control method for a forklift:

[0009] S1: Receive the lighting control command from the external device corresponding to the forklift through the pre-built CAN bus, and transmit it to the single-chip microcomputer. The single-chip microcomputer parses and processes the lighting control command according to the pre-set program, calculates the control signal and sends it to the mosfet output module. The mosfet output module adjusts the lamp current according to the control signal sent by the single-chip microcomputer control unit;

[0010] S2: The current value and temperature value of the mosfet output module are collected in real time through the pre-deployed sensors; and the real-time collected current value and temperature value are converted into electrical signals and transmitted to the single-chip microcomputer, and the single-chip microcomputer reads the converted electrical signals through the internal analog-to-digital converter, sets the evaluation time window, reads the current value and temperature value of the mosfet output module within the set time window, and performs comprehensive evaluation respectively, so as to obtain the overcurrent evaluation set and overheating evaluation set of the mosfet output module within the set time window; the overcurrent evaluation set includes an overcurrent trend graph and an overcurrent trend index, and the overheating evaluation set includes an overheating trend graph and an overheating trend index;

[0011] S3: Based on the overcurrent assessment set and overheat assessment set of the mosfet output module within the set time window, a corresponding warning signal is output, wherein the warning signal includes an overcurrent warning signal and an overheat warning signal.

[0012] As a preferred implementation of the present invention, the specific process of calculating the control signal is:

[0013] When the CAN bus receives the data frame corresponding to the lighting control instruction, it is sent to the microcontroller. The microcontroller first verifies and parses the data frame to extract the lighting control information. Then, based on the lighting control information, the microcontroller generates the corresponding control signal through the internal timer and counter resources, and sends it to the mosfet output module for operation.

[0014] As a preferred embodiment of the present invention, an overcurrent trend graph and an overheating trend graph of the mosfet output module within a set time window are obtained, specifically:

[0015] S2-1: extracting the current value at each time point within the set time window, and sorting them in chronological order to obtain a current sorting set within the set time window;

[0016] Set the reference threshold value corresponding to the current value;

[0017] Label the current sorted set as ; Where y represents the total number of time points, and x represents the current value;

[0018] The difference between each group of current values ​​in the current sorting set and the set reference threshold is calculated one by one, that is, ;in Indicates the reference threshold value set by the current value;

[0019] If the difference between the current value at a certain time point in the set time window and the reference threshold is a negative value, the negative value is taken as the absolute value and marked as the construction of a decreasing index; if the difference between the current value at a certain time point in the set time window and the reference threshold is a positive value, it is marked as the construction of an increasing index;

[0020] After sorting the calculated groups of differences in chronological order, starting from a group of pre-constructed starting points, if the first group of differences is to construct an ascending index, a line segment is constructed horizontally to the right from the starting point, and the length of the line segment is equal to the value of the first group of differences; if the first group of differences is to construct a descending index, a line segment is constructed vertically downward from the starting point, and the length of the line segment is equal to the value of the first group of differences;

[0021] After the line segment is constructed, the end of the constructed line segment is used as the starting point again, the next group of differences are extracted and the line segment is constructed again, until the line segments of each group of differences are constructed, and the overcurrent trend graph corresponding to the current value in the current set time window is formed;

[0022] S2-2: Similarly to step S2-1, the overheating trend graph corresponding to the temperature value in the current set time window is obtained.

[0023] As a preferred embodiment of the present invention, the overcurrent trend index and overheating trend index of the mosfet output module within the set time window are obtained, specifically:

[0024] S2-3: After calculating the average of each group of current values ​​within the set time window, the ratio between the calculated average and the reference threshold corresponding to the current value is calculated, that is, the average / reference threshold, to obtain the overcurrent trend index;

[0025] S2-4: Similarly, step S2-3 obtains the overheating trend index.

[0026] As a preferred embodiment of the present invention, the specific process of outputting the overcurrent warning signal and the overheating warning signal is as follows:

[0027] S3-2: firstly, extract the overcurrent trend index in the overcurrent evaluation set of the mosfet output module within the set time window, and extract the reference overcurrent trend index of each group of reference overcurrent evaluation sets from the historical evaluation database, and calculate the ratio between the overcurrent trend index in the overcurrent evaluation set of the mosfet output module within the set time window and the reference overcurrent trend index of each group of reference overcurrent evaluation sets, that is, overcurrent trend index / reference overcurrent trend index; calculate the difference between the calculated ratio of each group and the integer one and take the absolute value to obtain the similarity index ratio of each group of reference overcurrent evaluation sets;

[0028] The maximum allowable ratio corresponding to the similarity index ratio is set, each group of similarity index ratios is compared with the maximum allowable ratio, and a reference overcurrent evaluation set having a similarity index ratio lower than the maximum allowable ratio is retained as a screening overcurrent evaluation set;

[0029] Extract the reference overcurrent trend graph in the filtered overcurrent evaluation set, and calculate the Euclidean distance with the overcurrent trend graph of the mosfet output module within the set time window one by one;

[0030] A reference distance value corresponding to the Euclidean distance is set. If the Euclidean distance calculated by a certain group of screening overcurrent evaluation sets is lower than the set reference distance value, an overcurrent warning signal is triggered. If there is more than one group of screening overcurrent evaluation sets that are lower than the set reference distance value, the screening overcurrent evaluation set with the smallest Euclidean distance is selected from the Euclidean distances calculated by each group of screening overcurrent evaluation sets as the reference historical overcurrent fault corresponding to the current triggering of the overcurrent warning signal.

[0031] S3-3: Similarly, step S3-2 triggers an overheating warning signal, and determines a reference historical overheating fault.

[0032] As a preferred embodiment of the present invention, the specific process of constructing the historical evaluation database is as follows:

[0033] S3-1: Taking each historical overcurrent fault and overheating fault as reference data, analyze the overcurrent evaluation set and overheating evaluation set in the set time window before the occurrence time point of each group of overcurrent fault and overheating fault, as the reference overcurrent evaluation set and the reference overheating evaluation set, and construct a historical evaluation database; the reference overcurrent evaluation set includes a reference overcurrent trend graph and a reference overcurrent trend index; the reference overheating evaluation set includes a reference overheating trend graph and a reference overheating trend index.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention uses embedded single-chip microcomputer technology to communicate with the CAN bus, greatly simplifying the vehicle body wiring harness structure, making the configuration and control of the lights more convenient and flexible. The contactless control method of the MOSFET output module avoids the problems of arcing, ablation and heating caused by mechanical contacts, effectively improving reliability and stability.

[0036] The present invention uses embedded single-chip microcomputer technology to communicate with the CAN bus to receive light control instructions from external equipment of the forklift. The single-chip microcomputer parses and processes the instructions, and generates corresponding control signals based on the light control information using internal timer and counter resources to realize functions such as turning on and off, flashing, and dimming of the light, making the configuration and control of the light more convenient and flexible, while simplifying the vehicle body wiring harness structure.

[0037] The present invention constructs a historical evaluation database, takes historical overcurrent faults and overheating faults as reference data, analyzes the overcurrent evaluation set and the overheating evaluation set in a set time window before the fault occurs as reference data, collects the current value and temperature value of the MOSFET output module in real time, calculates the overcurrent evaluation set and the overheating evaluation set, compares the current trend index with the historical data to calculate the similarity index ratio, screens out similar reference sets, and further determines the degree of similarity by calculating the Euclidean distance. When the Euclidean distance is lower than the set reference distance value, the corresponding overcurrent or overheating warning signal is triggered, and the most similar reference historical fault can be found, providing a clear direction and detailed reference information for technicians to trace the root cause of the fault, facilitating the maintenance and troubleshooting of forklifts, and reducing maintenance costs and downtime. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0039] Figure 1 is a flow chart of the present invention;

[0040] Figure 2 A schematic diagram of an overcurrent trend graph in the present invention;

[0041] Figure 3 This is a schematic diagram of the lighting control principle of the present invention. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] See also Figure 1-Figure 3 As shown, a CAN bus lighting control method for a forklift includes:

[0044] S1: Receive the lighting control command from the external device corresponding to the forklift through the pre-built CAN bus, and transmit it to the single-chip microcomputer. The single-chip microcomputer parses and processes the lighting control command according to the pre-set program, calculates the control signal and sends it to the mosfet output module. The mosfet output module adjusts the lamp current according to the control signal sent by the single-chip microcomputer control unit, so as to achieve the functions of turning on, off, flashing and dimming the light;

[0045] The MCU initializes the CAN bus, including baud rate configuration, data frame format setting, etc. At the same time, it initializes the internal timer, counter and related registers to prepare for subsequent command parsing and control signal generation;

[0046] The specific process of calculating the control signal is:

[0047] When the CAN bus receives the data frame corresponding to the lighting control command, it is sent to the MCU. The MCU first verifies and parses the data frame to extract the lighting control information, such as the lighting operation type (on, off, flashing frequency, dimming level, etc.) and the corresponding lamp number. Then, based on the lighting control information, the MCU generates the corresponding control signal through the internal timer and counter resources; the control signal is a pulse width modulation (PWM) signal or a digital control signal, and is sent to the MOSFET output module for operation.

[0048] For example, in the dimming function implementation process, the MCU adjusts the duty cycle of the output PWM signal according to the dimming level information in the instruction; the larger the duty cycle, the greater the average current of the lamp and the brighter the light; vice versa, the dimmer it is; for the flickering function, the MCU controls the lamp to turn on and off alternately within a certain time interval according to the set flickering frequency, and achieves a stable flickering effect through precise timer interrupt settings;

[0049] When the CAN bus receives a data frame, the MCU receives the data frame according to the preset CAN communication protocol; then, the data frame is checked, such as by using cyclic redundancy check (CRC) to ensure the accuracy of data transmission;

[0050] Parse the data frame and extract the lighting control information, such as the lighting operation type (on, off, flashing frequency, dimming level, etc.) and the corresponding lighting fixture number;

[0051] If the operation type is "on", the microcontroller outputs a high-level digital signal; if it is "off", it outputs a low-level digital signal. These signals directly act on the control end of the mosfet output module to control the conduction and cutoff of the mosfet, and then control the on and off of the lamp;

[0052] The flicker frequency refers to how fast the light flickers, usually expressed in the number of flickers per second (Hz). The microcontroller uses the internal timer to set the flickering time interval based on the received flickering frequency parameters. For example, if the flickering frequency is 2Hz, that is, 2 flickers per second, then the time interval between each flicker is 0.5 seconds.

[0053] Dimming levels are usually expressed as percentages, ranging from 0% (totally dark) to 100% (brightest). The microcontroller converts the dimming level parameters into the corresponding PWM signal duty cycle. The duty cycle refers to the ratio of the duration of the high level of the PWM signal to the total time of one cycle. For example, if the dimming level is 50%, the corresponding PWM signal duty cycle is also 50%;

[0054] S2: The current value and temperature value of the mosfet output module are collected in real time through the pre-deployed sensors; that is, the current value and temperature value collected in real time are collected through the pre-deployed temperature sensor and current sensor; and the real-time collected current value and temperature value are converted into electrical signals and transmitted to the single-chip microcomputer, and the single-chip microcomputer reads the converted electrical signals through the internal analog-to-digital converter, sets the evaluation time window, reads the current value and temperature value of the mosfet output module within the set time window, and performs comprehensive evaluation respectively, so as to obtain the overcurrent evaluation set and overheating evaluation set of the mosfet output module within the set time window; the overcurrent evaluation set includes an overcurrent trend graph and an overcurrent trend index, and the overheating evaluation set includes an overheating trend graph and an overheating trend index;

[0055] Specifically:

[0056] S2-1: extracting the current value at each time point within the set time window, and sorting them in chronological order to obtain a current sorting set within the set time window;

[0057] Set the reference threshold corresponding to the current value; it is set by the technicians and can be dynamically adjusted according to the actual situation;

[0058] Label the current sorted set as ; Where y represents the total number of time points, and x represents the current value;

[0059] The difference between each group of current values ​​in the current sorting set and the set reference threshold is calculated one by one, that is, ;in Indicates the reference threshold value set by the current value;

[0060] If the difference between the current value at a certain time point in the set time window and the reference threshold is a negative value, the negative value is taken as the absolute value and marked as the construction of a decreasing index; if the difference between the current value at a certain time point in the set time window and the reference threshold is a positive value, it is marked as the construction of an increasing index;

[0061] After sorting the calculated groups of differences in chronological order, starting from a group of pre-constructed starting points, if the first group of differences is to construct an ascending index, a line segment is constructed horizontally to the right from the starting point, and the length of the line segment is equal to the value of the first group of differences; if the first group of differences is to construct a descending index, a line segment is constructed vertically downward from the starting point, and the length of the line segment is equal to the value of the first group of differences;

[0062] After the line segment is constructed, the end of the constructed line segment is used as the starting point again, the next group of differences are extracted and the line segment is constructed again, until the line segments of each group of differences are constructed, and the overcurrent trend graph corresponding to the current value in the current set time window is formed;

[0063] It should be noted that, assuming that the time window is set to 5 time points, the current values ​​collected at each time point are: [12A, 8A, 15A, 9A, 13A]; the current sorting set is obtained in chronological order. Here y=5 (the total number of time points), the corresponding current values ​​are x1=12A, x2=8A, x3=15A, x4=9A, x5=13A; the set is represented as {(1,12), (2,8), (3,15), (4,9), (5,13)}, the first number in the brackets represents the time point number, and the second number represents the current value at that time point;

[0064] The technical personnel set the reference threshold corresponding to the current value to 10A;

[0065] The difference between each current value in the current sorting set and the set reference threshold 10A is calculated:

[0066] For time point 1, the current value x1=12A, and the difference is 12-10=2A (positive value);

[0067] At time point 2, the current value is x2=8A, the difference is 8-10=-2A (negative value), and the absolute value is 2A;

[0068] For time point 3, the current value is x3=15A, and the difference is 15-10=5A (positive value);

[0069] At time point 4, the current value is x4=9A, the difference is 9-10=-1A (negative value), and the absolute value is 1A;

[0070] At time point 5, the current value is x5=13A, and the difference is 13-10=3A (positive value);

[0071] The difference 2A at time point 1 is positive and is marked as constructing an ascending index;

[0072] The absolute value of the difference at time point 2 is 2A, which is marked as the constructed decline index;

[0073] The difference 5A at time point 3 is positive and is marked as constructing an ascending index;

[0074] The absolute value of the difference at time point 4 is 1A, which is marked as the constructed decline index;

[0075] The difference 3A at time point 5 is positive and is marked as constructing an ascending index;

[0076] Assume that the pre-built starting point is the coordinate origin (0,0):

[0077] The first set of differences (time point 1) is used to construct the rising index. Starting from the starting point (0,0), a line segment is constructed horizontally to the right. The length of the line segment is 2 units (corresponding to the difference 2A), and the point is reached (2,0).

[0078] The second set of differences (time point 2) is used to construct a descending index. A line segment is constructed from point (2,0) vertically downward. The length of the line segment is 2 units (corresponding to the absolute value of the difference 2A), and the line segment reaches point (2,-2).

[0079] The third set of differences (time point 3) is used to construct the rising index. Starting from point (2, -2), a line segment is constructed horizontally to the right. The length of the line segment is 5 units (corresponding to the difference 5A), and the line segment reaches point (7, -2).

[0080] The fourth set of differences (time point 4) is used to construct a descending index. A line segment is constructed from point (7, -2) downward in the vertical direction. The length of the line segment is 1 unit (corresponding to the absolute value of the difference 1A), and the line segment reaches point (7, -3).

[0081] The fifth set of differences (time point 5) is to construct an ascending index. Starting from point (7, -3), a line segment is constructed horizontally to the right. The length of the line segment is 3 units (corresponding to the difference 3A), and the line segment reaches point (10, -3).

[0082] Finally, these points are connected in sequence to form an overcurrent trend graph corresponding to the current value in the current set time window.

[0083] S2-2: extract the temperature values ​​at each time point within the set time window, and sort them in chronological order to obtain a temperature sorting set within the set time window;

[0084] The reference threshold corresponding to the set temperature value is set by the technical staff and can be dynamically adjusted according to the actual situation later;

[0085] Label the sorted set of temperatures as ; Where j represents the total number of time points, and z is the current value;

[0086] The difference between each temperature value in the temperature sorting set and the set reference threshold is calculated one by one, that is, ;in Indicates the reference threshold value set by the temperature value;

[0087] If the difference between the temperature value at a certain time point in the set time window and the reference threshold is a negative value, the negative value is taken as the absolute value and marked as the construction of the descending index; if the difference between the temperature value at a certain time point in the set time window and the reference threshold is a positive value, it is marked as the construction of the ascending index;

[0088] After sorting the calculated groups of differences in chronological order, starting from a group of pre-constructed starting points, if the first group of differences is to construct an ascending index, a line segment is constructed horizontally to the right from the starting point, and the length of the line segment is equal to the value of the first group of differences; if the first group of differences is to construct a descending index, a line segment is constructed vertically downward from the starting point, and the length of the line segment is equal to the value of the first group of differences;

[0089] After the line segment is constructed, the end of the constructed line segment is used as the starting point again, the next group of differences are extracted and the line segment is constructed again, until the line segments of each group of differences are constructed, and the overheating trend graph corresponding to the temperature value in the current set time window is formed;

[0090] S2-3: After calculating the average of each group of current values ​​within the set time window, the ratio between the calculated average and the reference threshold corresponding to the current value is calculated, that is, the average / reference threshold, to obtain the overcurrent trend index;

[0091] S2-4: After calculating the average of each group of temperature values ​​within the set time window, the ratio between the calculated average and the reference threshold corresponding to the temperature value is calculated, that is, the average / reference threshold, to obtain the overheating trend index;

[0092] S3: Based on the overcurrent evaluation set and overheating evaluation set of the mosfet output module within the set time window, output a corresponding warning signal, wherein the warning signal includes an overcurrent warning signal and an overheating warning signal;

[0093] Specifically:

[0094] S3-1: Taking each historical overcurrent fault and overheating fault as reference data, analyze the overcurrent evaluation set and overheating evaluation set in the set time window before the occurrence time point of each group of overcurrent fault and overheating fault, as the reference overcurrent evaluation set and the reference overheating evaluation set, and construct a historical evaluation database; the reference overcurrent evaluation set includes a reference overcurrent trend graph and a reference overcurrent trend index; the reference overheating evaluation set includes a reference overheating trend graph and a reference overheating trend index;

[0095] S3-2: First, extract the overcurrent trend index in the overcurrent evaluation set of the mosfet output module within the set time window, and extract the reference overcurrent trend index of each group of reference overcurrent evaluation sets from the historical evaluation database, and calculate the ratio between the overcurrent trend index in the overcurrent evaluation set of the mosfet output module within the set time window and the reference overcurrent trend index of each group of reference overcurrent evaluation sets, that is, overcurrent trend index / reference overcurrent trend index; calculate the difference between the calculated ratio of each group and the integer one and take the absolute value to obtain the similarity index ratio of each group of reference overcurrent evaluation sets; the smaller the similarity index ratio, the closer the two groups of indexes are;

[0096] The maximum allowable ratio corresponding to the similarity index ratio is set, each group of similarity index ratios is compared with the maximum allowable ratio, and a reference overcurrent evaluation set having a similarity index ratio lower than the maximum allowable ratio is retained as a screening overcurrent evaluation set;

[0097] Extract the reference overcurrent trend graph in the filtered overcurrent evaluation set, and calculate the Euclidean distance with the overcurrent trend graph of the MOSFET output module in the set time window one by one; the smaller the Euclidean distance, the higher the similarity;

[0098] A reference distance value corresponding to the Euclidean distance is set. If the Euclidean distance calculated by a certain group of screening overcurrent evaluation sets is lower than the set reference distance value, an overcurrent warning signal is triggered. If there is more than one group of screening overcurrent evaluation sets that are lower than the set reference distance value, the screening overcurrent evaluation set with the smallest Euclidean distance is selected from the Euclidean distances calculated by each group of screening overcurrent evaluation sets as the reference historical overcurrent fault corresponding to the current triggering of the overcurrent warning signal.

[0099] S3-3: firstly, extract the overheating trend index in the overheating evaluation set of the mosfet output module within the set time window, and extract the reference overheating trend index of each group of reference overheating evaluation sets from the historical evaluation database, and calculate the ratio between the overheating trend index in the overheating evaluation set of the mosfet output module within the set time window and the reference overheating trend index of each group of reference overheating evaluation sets, that is, overheating trend index / reference overheating trend index; calculate the difference between the calculated ratio of each group and the integer one and take the absolute value to obtain the similarity index ratio of each group of reference overheating evaluation sets; the smaller the similarity index ratio is, the closer the two groups of indexes are;

[0100] The maximum allowable ratio corresponding to the similarity index ratio is set, each group of similarity index ratios is compared with the maximum allowable ratio, and a reference overheating assessment set whose similarity index ratio is lower than the maximum allowable ratio is retained as a screening overheating assessment set;

[0101] Extract the reference overheating trend graph in the filtered overheating assessment set, and calculate the Euclidean distance with the overheating trend graph of the mosfet output module in the set time window one by one; the smaller the Euclidean distance, the higher the similarity;

[0102] A reference distance value corresponding to the Euclidean distance is set. If the Euclidean distance calculated by a certain group of screening overheating assessment sets is lower than the set reference distance value, an overheating warning signal is triggered. If there is more than one group of screening overheating assessment sets lower than the set reference distance value, the screening overheating assessment set with the smallest Euclidean distance is selected from the Euclidean distances calculated by each group of screening overheating assessment sets as the reference historical overheating fault corresponding to the current triggering of the overheating warning signal.

[0103] It should be noted that by building a historical evaluation database and comparing the current status with historical fault data, based on precise calculations such as similarity index ratio and Euclidean distance, it is possible to more accurately determine whether there is an overcurrent or overheating risk and trigger an early warning, thereby reducing false alarms and missed alarms and ensuring the stable operation of the forklift in advance.

[0104] When an early warning is triggered, the most similar reference historical faults can be quickly found from the historical evaluation database, providing clear direction and detailed reference information for technicians to trace the root cause of the current fault, shortening the troubleshooting time, improving maintenance efficiency, and reducing forklift downtime and maintenance costs.

[0105] S3-4: If an overcurrent warning signal is triggered, a control signal is sent to the mosfet output module to cut off its output, thereby protecting the lamp and the entire circuit from damage due to overcurrent. For example, the microcontroller can change the gate voltage of the mosfet to put it in a cut-off state, thereby cutting off the current. If an overheat warning signal is triggered, the power supply of the mosfet output module is cut off, and the triggered overcurrent warning signal and overheat warning signal are sent to the management at the same time.

[0106] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A CAN bus lighting control method for a forklift, characterized in that: include: S1: Receive the lighting control command from the external device corresponding to the forklift through the pre-built CAN bus, and transmit it to the single-chip microcomputer. The single-chip microcomputer parses and processes the lighting control command according to the pre-set program, calculates the control signal and sends it to the mosfet output module. The mosfet output module adjusts the lamp current according to the control signal sent by the single-chip microcomputer control unit; S2: collect the current value and temperature value of the mosfet output module in real time through the pre-arranged sensors; The real-time collected current value and temperature value are converted into electrical signals and transmitted to the single-chip microcomputer. The single-chip microcomputer reads the converted electrical signals through the internal analog-to-digital converter, sets the evaluation time window, reads the current value and temperature value of the mosfet output module within the set time window, and performs comprehensive evaluation respectively, so as to obtain the overcurrent evaluation set and overheating evaluation set of the mosfet output module within the set time window; the overcurrent evaluation set includes an overcurrent trend graph and an overcurrent trend index, and the overheating evaluation set includes an overheating trend graph and an overheating trend index; S2-1: extracting the current value at each time point within the set time window, and sorting them in chronological order to obtain a current sorting set within the set time window; Set the reference threshold value corresponding to the current value; Label the current sorted set as ; Where y represents the total number of time points, and x represents the current value; The difference between each group of current values ​​in the current sorting set and the set reference threshold is calculated one by one, that is, ;in Indicates the reference threshold value set by the current value; If the difference between the current value at a certain time point in the set time window and the reference threshold is a negative value, the negative value is taken as the absolute value and marked as the construction of a decreasing index; if the difference between the current value at a certain time point in the set time window and the reference threshold is a positive value, it is marked as the construction of an increasing index; After sorting the calculated groups of differences in chronological order, starting from a group of pre-constructed starting points, if the first group of differences is to construct an ascending index, a line segment is constructed horizontally to the right from the starting point, and the length of the line segment is equal to the value of the first group of differences; if the first group of differences is to construct a descending index, a line segment is constructed vertically downward from the starting point, and the length of the line segment is equal to the value of the first group of differences; After the line segment is constructed, the end of the constructed line segment is used as the starting point again, the next group of differences are extracted and the line segment is constructed again, until the line segments of each group of differences are constructed, and the overcurrent trend graph corresponding to the current value in the current set time window is formed; S2-2: similarly to step S2-1, obtain the overheating trend graph corresponding to the temperature value in the current set time window; S2-3: After calculating the average of each group of current values ​​within the set time window, the ratio between the calculated average and the reference threshold corresponding to the current value is calculated, that is, the average / reference threshold, to obtain the overcurrent trend index; S2-4: similarly to step S2-3, the overheating trend index is obtained; S3: Based on the overcurrent evaluation set and overheating evaluation set of the mosfet output module within the set time window, output a corresponding warning signal, wherein the warning signal includes an overcurrent warning signal and an overheating warning signal; Output over-current warning signal and over-heat warning signal, specifically: S3-1: Taking each historical overcurrent fault and overheating fault as reference data, analyze the overcurrent evaluation set and overheating evaluation set in the set time window before the occurrence time point of each group of overcurrent fault and overheating fault, as the reference overcurrent evaluation set and the reference overheating evaluation set, and construct a historical evaluation database; the reference overcurrent evaluation set includes a reference overcurrent trend graph and a reference overcurrent trend index; the reference overheating evaluation set includes a reference overheating trend graph and a reference overheating trend index; S3-2: firstly, extract the overcurrent trend index in the overcurrent evaluation set of the mosfet output module within the set time window, and extract the reference overcurrent trend index of each group of reference overcurrent evaluation sets from the historical evaluation database, and calculate the ratio between the overcurrent trend index in the overcurrent evaluation set of the mosfet output module within the set time window and the reference overcurrent trend index of each group of reference overcurrent evaluation sets, that is, overcurrent trend index / reference overcurrent trend index; calculate the difference between the calculated ratio of each group and the integer one and take the absolute value to obtain the similarity index ratio of each group of reference overcurrent evaluation sets; The maximum allowable ratio corresponding to the similarity index ratio is set, each group of similarity index ratios is compared with the maximum allowable ratio, and a reference overcurrent evaluation set having a similarity index ratio lower than the maximum allowable ratio is retained as a screening overcurrent evaluation set; Extract the reference overcurrent trend graph in the filtered overcurrent evaluation set, and calculate the Euclidean distance with the overcurrent trend graph of the mosfet output module within the set time window one by one; A reference distance value corresponding to the Euclidean distance is set. If the Euclidean distance calculated by a certain group of screening overcurrent evaluation sets is lower than the set reference distance value, an overcurrent warning signal is triggered. If there is more than one group of screening overcurrent evaluation sets that are lower than the set reference distance value, the screening overcurrent evaluation set with the smallest Euclidean distance is selected from the Euclidean distances calculated by each group of screening overcurrent evaluation sets as the reference historical overcurrent fault corresponding to the current triggering of the overcurrent warning signal. S3-3: Similarly, step S3-2 triggers an overheating warning signal, and determines a reference historical overheating fault.

2. A CAN bus lighting control method for a forklift according to claim 1, characterized in that: The specific process of calculating the control signal is: When the CAN bus receives the data frame corresponding to the lighting control instruction, it is sent to the microcontroller. The microcontroller first verifies and parses the data frame to extract the lighting control information. Then, based on the lighting control information, the microcontroller generates the corresponding control signal through the internal timer and counter resources, and sends it to the mosfet output module for operation.

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