A dual pedal control method for improving the safety of terminal machine operation

Abstract

The application discloses a double-pedal control method for improving the operation safety of a terminal machine, and belongs to the technical field of terminal machine safety control. The method comprises the following steps: acquiring real-time position signals and pressure signals of left and right pedals on the operation side; collecting an infrared grid distribution map of a working area of the terminal machine, and dividing the infrared grid distribution map into multiple safety areas; generating left-pedal pulse sequences and right-pedal pulse sequences according to the real-time position signals and pressure signals of the left and right pedals; comparing the left-pedal pulse sequences and the right-pedal pulse sequences with a preset cooperative authentication pulse table; when the intersection area of the left-pedal pulse sequences and the right-pedal pulse sequences is located in a predetermined safety area, enabling a stamping enabling lock of the terminal machine; and controlling a servo motor driver of the terminal machine through the stamping enabling lock to perform corresponding stamping actions. The method utilizes the double-pedal pulse cooperative authentication and the infrared grid safety area linkage, and effectively prevents hand injury accidents caused by missteps.

Description

Technical Field

[0001] This invention relates to the field of terminal block machine safety control technology, specifically a dual-pedal control method to improve the operational safety of terminal block machines. Background Technology

[0002] Terminal crimping machines are used in wire harness processing to crimp terminals to wires. The crimping action is typically triggered by the operator via a foot switch. Traditional terminal crimping machines often use a single pedal to control the start and stop of the crimping process. During prolonged, repetitive work, operators are prone to accidentally stepping on the wrong pedal due to fatigue or distraction. If the operator's hand is in the crimping area, this can easily cause serious accidents such as crushing injuries or even severed fingers. Some improved solutions replace the single pedal with two independent pedals, requiring the operator to press both feet simultaneously to activate the crimping circuit. This simple "dual-pedal and logic" approach only prevents accidental single-foot activation, but it cannot distinguish whether the pedals are pressed down normally by the operator, or whether the operator presses down two pedals simultaneously with a heavy object or by using the same foot, leaving significant safety vulnerabilities.

[0003] To detect whether hands have entered the danger zone, some equipment is equipped with safety light curtains or infrared sensors, which forcibly cut off the drive signal when the beam is blocked. However, existing light curtain detection methods mostly output a single signal indicating the presence of obstruction, failing to reflect the depth of the hand entering the mold area, nor can they correlate the hand's position with the dynamic process of pedal operation in time. When operators alternately pick up workpieces with both hands, they may step on the pedal for a brief moment when the light curtain is not blocked, or suddenly insert their hand after the pedal has been pressed. Existing static safety logic cannot make timely and accurate judgments on such dynamic cross-processes, and the risk of hand injury from stamping remains. How to accurately identify the true intention of pedal operation during dual-pedal operation and precisely link the timing of pedal pressing with changes in the depth of hand insertion is a problem that needs to be solved to improve the safety of terminal crimping machine operation. Summary of the Invention

[0004] This invention provides a dual-pedal control method to improve the safety of terminal crimping machine operation, addressing the problems in existing terminal crimping machine control systems where it is difficult to effectively identify the intention of pedal operation and the inability to dynamically link the depth of hand insertion with the timing of pedal operation. By encoding and coordinating the position and pressure signals of the left and right pedals with pulse sequences, and combining this with infrared grid distribution maps to divide safe areas, the safety of the pulse intersection area is determined, achieving precise control of the stamping enable and eliminating the risks of accidental pedaling and initiating stamping when the hand is in a high-risk area.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides a dual-pedal control method to improve the safety of terminal block machine operation. By coordinating the detection of the status of the left and right pedals on the operation side and combining the infrared grid safety zone division of the working area, dual safety protection for the stamping action is achieved.

[0006] This method acquires real-time position and pressure signals of the left and right pedals on the operating side; simultaneously, it collects an infrared grid distribution map of the terminal block machine's working area and divides the map into multiple safe zones. Based on the real-time position and pressure signals of the left and right pedals, corresponding left and right pedal pulse sequences are generated and compared with a preset collaborative authentication pulse table. When the intersection of the left and right pedal pulse sequences falls within a predetermined safe zone, the terminal block machine's punching enable lock is activated. This lock controls the terminal block machine's servo motor driver to execute the corresponding punching action.

[0007] Preferably, when acquiring pedal signals, the displacement of the pedals is continuously collected by the built-in magnetic displacement sensors of the left and right pedals, and the pedal pressure is simultaneously collected by the built-in piezoelectric force sensors of the pedals. The pedal pressure and pedal displacement are aligned according to timestamps to generate left pedal state vectors and right pedal state vectors. This method can accurately reproduce the operator's foot movement intentions and avoid accidental activation caused by single pedal mis-touch or non-human-induced pedaling.

[0008] As a technical solution of the present invention, during the safety zone division process, the horizontal infrared emitting tube and the vertical infrared receiving tube are controlled to scan and obtain the occlusion matrix of the working area; the insertion position and depth of the operator are identified according to the number of consecutive dark spots in the occlusion matrix; areas with an insertion depth less than a preset first threshold are marked as low-risk areas, and areas with an insertion depth greater than a preset second threshold are marked as high-risk areas. Therefore, it is possible to determine in real time whether the operator is in a dangerous position before the stamping action is executed, providing an accurate regional basis for subsequent enable judgment.

[0009] When generating the pulse sequence, the displacement change rate in the left pedal state vector is extracted, and the time period when the displacement change rate exceeds a preset rate threshold is marked as the effective travel segment of the left pedal. Within the effective travel segment of the left pedal, the timing points where the pedaling force exceeds a preset start threshold are extracted to generate a continuous left pedal pulse sequence. The right pedal state vector is extracted in the same way to generate a continuous right pedal pulse sequence. This pulse generation method can filter out unintentional slow pedaling or slight touches, generating effective pulses only for forceful pedaling with a clear operational intention, preventing false triggering caused by pedal position drift or resting the foot.

[0010] For collaborative authentication, pulse width encoding is performed on the left and right pedal pulse sequences respectively to generate left and right pedal width codes. The phase difference between the left and right pedal width codes is extracted. When the phase difference falls within the allowable phase difference range recorded in the collaborative authentication pulse table, the pulse sequence is considered to be successfully matched. By comparing the phase difference, it can be ensured that both left and right pedals are not only pressed down, but also have a timing relationship that conforms to operating habits, preventing the risk of the other pedal being accidentally triggered after one pedal has been continuously pressed down.

[0011] Once the pulse sequence matching is successful, the overlap interval between the left and right pedal pulse sequences on the time axis is calculated. It is then determined whether all time points corresponding to the overlap interval fall within the duration of the low-risk zone. If the entire overlap interval falls within the duration of the low-risk zone, a high-level enable signal is output to the stamping enable lock. Specifically, the start and end times of the overlap interval are compared with the start and end times of the low-risk zone. If the start time of the overlap interval is later than the start time of the low-risk zone and the end time of the overlap interval is earlier than the end time of the low-risk zone, an overlap interval compliance flag is output, and this compliance flag is used as one of the triggering conditions for the stamping enable lock. In this way, even if the dual-pedal operation is successfully authenticated, if the operator has already entered the high-risk area during that time period, the enable signal will not be triggered, achieving mandatory interlocking of electrical control and spatial safety status.

[0012] During the stamping execution phase, the high-level enable signal output from the stamping enable lock is input to the enable port of the servo motor driver; the current pressure signals of the left and right pedals are read, and the acceleration curve slope of the servo motor is allocated according to the pressure ratio; the servo motor is driven to perform a downward pressing action according to the acceleration curve slope until the predetermined end point of the stroke is reached. By utilizing the acceleration characteristic of adjusting the pressure ratio of the two feet, the initial speed of the stamping process is correlated with the operator's pedal force distribution. The operator can control the initial pressing speed by adjusting the force applied by both feet, improving the operating feel and the controllability of the process.

[0013] To further enhance safety, this invention performs differential calculations on the displacement of the left and right pedals with their respective previous sampled values ​​to obtain instantaneous displacement increments. These instantaneous displacement increments are then accumulated to obtain a cumulative displacement value. When the cumulative displacement value exceeds the preset maximum safe travel, the control circuit of the stamping enable lock is forcibly disconnected. This cumulative travel monitoring can prevent the enable condition from being accidentally reached due to the continuous accumulation of displacement signals when the pedal itself experiences mechanical jamming or sensor malfunction, providing an additional layer of protection for the system.

[0014] In addition, a synchronization check pulse is inserted into the pulse sequence of the left and right pedals; the synchronization check pulse is compared with a preset reference clock signal; when the deviation between the synchronization check pulse and the reference clock signal exceeds the preset drift limit, a lock signal is sent to the emergency stop circuit to prevent misjudgment caused by the pulse sequence being out of phase due to clock deviation or signal asynchrony.

[0015] This invention uses real-time dynamic authentication of the position and pressure of the dual pedals, along with hierarchical interlocking with the infrared safety grid in the work area, to ensure that the stamping enable lock is only activated when the operator's hands are in a low-risk area and both feet complete the stepping action that conforms to the preset coordination relationship. Any single fault, misoperation, or dangerous insertion behavior will be blocked in real time, effectively eliminating the risk of squeezing and shearing during the terminal block stamping process, and significantly improving inherent safety while ensuring production efficiency.

[0016] The technical effects and advantages provided by the present invention in the above technical solution are as follows: By extracting the displacement change rate from the state vectors of the left and right pedals, time periods where the displacement change rate exceeds a preset rate threshold are marked as valid travel segments. Within these valid travel segments, time points where the pedaling force exceeds a preset start threshold are extracted, generating continuous left and right pedal pulse sequences. Pulse width encoding is performed on the pulse sequences to obtain left and right pedal width codes, and the phase difference between them is extracted. The phase difference is compared with the allowable phase difference range recorded in a preset collaborative authentication pulse table. Only when the phase difference falls within the allowable range is the pulse sequence considered a successful match. This method incorporates the timing, pulse width, and phase difference of the operator's two pedals into the collaborative authentication conditions. Only when the pedaling dynamic process conforms to the allowable range of the preset authentication pulse table is the system recognized as a valid collaborative operation, eliminating the possibility of bypassing the safety mechanism by simultaneously applying static pressure to both pedals with foreign objects or using abnormal pedaling rhythms. A synchronization check pulse is inserted into the pulse sequence and compared with a preset reference clock signal. When the deviation exceeds the drift limit, a lock signal is sent to the emergency stop circuit. This can promptly block the stamping when the pedal sensor experiences abnormal drift, preventing false triggering caused by device aging or failure.

[0017] The system controls the horizontal infrared emitter and vertical infrared receiver to scan and acquire the occlusion matrix of the working area. Based on the number of consecutive dark spots in the occlusion matrix, the system identifies the hand's insertion position and depth. Areas with insertion depths less than a first threshold are marked as low-risk areas, while areas with depths greater than a second threshold are marked as high-risk areas. The system calculates the overlap interval between the left and right pedal pulse sequences on the time axis and determines whether the start and end times of the overlap interval fall entirely within the duration of the low-risk area. Only when the overlap interval completely falls within the duration corresponding to the low-risk area is a high-level enable signal output to the stamping enable lock. This process precisely compares the depth of hand insertion with the overlap time window of the pedal pulses, ensuring that even if pedal co-authentication passes, the enable lock will not open if the hand insertion depth enters the high-risk area. A strict interlocking relationship is formed between hand depth changes and pedal operation on the time axis, eliminating the possibility of stamping injury when the hand is in the high-risk area. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a flowchart of a dual-pedal control method to improve the safety of terminal block machine operation; Figure 2 This is a flowchart of the pedal pulse sequence generation and synchronization verification process; Figure 3 This is a comparison chart of the time margins of the pulse sequences for the left and right pedals. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] See Figure 1This invention provides a dual-pedal control method to improve the safety of terminal crimping machine operation, comprising: acquiring real-time position signals and pressure signals of the left and right pedals on the operating side; acquiring an infrared grid distribution map of the terminal crimping machine's working area and dividing the infrared grid distribution map into multiple safe zones; generating a left pedal pulse sequence and a right pedal pulse sequence based on the real-time position signals and pressure signals of the left and right pedals; comparing the left pedal pulse sequence and the right pedal pulse sequence with a preset collaborative authentication pulse table; when the intersection area of ​​the left pedal pulse sequence and the right pedal pulse sequence is located in a predetermined safe zone, activating the terminal crimping machine's punching enable lock; and controlling the terminal crimping machine's servo motor driver through the punching enable lock to execute the corresponding punching action.

[0022] Example 1 In the specific implementation, real-time position and pressure signals of the left and right pedals on the operating side are acquired. Both the left and right pedals have built-in magnetic displacement sensors. The magnetic displacement sensors in the left and right pedals continuously acquire the displacement of the left pedal, and vice versa. Both the left and right pedals also have built-in piezoelectric force sensors. The piezoelectric force sensors in the left and right pedals simultaneously acquire the pedal pressure, and vice versa. The pedal pressure and displacement of the left pedal are aligned according to timestamps to generate a left pedal state vector. This left pedal state vector includes the left pedal displacement, pedal pressure, and the corresponding timestamp. Similarly, the pedal pressure and displacement of the right pedal are aligned according to timestamps to generate a right pedal state vector. This right pedal state vector includes the right pedal displacement, pedal pressure, and the corresponding timestamp.

[0023] An infrared grid distribution map of the terminal crimping machine's working area is collected and divided into multiple safe zones. In practice, the horizontal infrared emitter and vertical infrared receiver are controlled to scan and obtain an occlusion matrix of the working area. Each element in the occlusion matrix corresponds to the on / off state of an intersecting optical path point; occluded elements are recorded as dark spots. The insertion position and depth of the operator's hand are identified based on the number of consecutive dark spots in the occlusion matrix. A higher number of consecutive dark spots indicates a greater depth of the operator's hand into the working area. The insertion depth is compared to a preset first threshold; areas with a depth less than the preset first threshold are marked as low-risk zones. The insertion depth is compared to a preset second threshold; areas with a depth greater than the preset second threshold are marked as high-risk zones. The preset first threshold is less than the preset second threshold. The preset first threshold is determined based on the distance between the terminal crimping machine mold's closed area and the safe operating boundary, while the preset second threshold is determined based on the minimum safe distance of the terminal crimping machine mold's cutting edge area.

[0024] Acquiring the real-time position and pressure signals of the left and right pedals on the operating side also includes the following processing: The displacement of the left pedal is differentially calculated with its previous sampled value to obtain the instantaneous displacement increment of the left pedal. The displacement of the right pedal is differentially calculated with its previous sampled value to obtain the instantaneous displacement increment of the right pedal. The instantaneous displacement increments of the left pedal are accumulated to obtain the cumulative displacement value of the left pedal. The instantaneous displacement increments of the right pedal are accumulated to obtain the cumulative displacement value of the right pedal. The cumulative displacement value of the left pedal is calculated using the following formula: in, This represents the cumulative displacement value of the left pedal. This is the sequence number of the sampling period. This represents the total number of sampling periods from the start of the stampede to the current moment. For the first The instantaneous displacement increment of the left pedal obtained in each sampling period , For the first The displacement of the left pedal collected at each sampling time. For the first The left pedal displacement is collected at each sampling time. The right pedal cumulative displacement value is calculated in the same way as the left pedal cumulative displacement value, using the right pedal displacement value for corresponding differentiation and accumulation. When the left pedal cumulative displacement value exceeds the preset maximum safety travel, the control circuit of the stamping enable lock is forcibly cut off. The preset maximum safety travel is set according to the mechanical limit travel of the left and right pedals, and the maximum safety travel corresponding to the left pedal is the same as that corresponding to the right pedal.

[0025] Example 2 In specific implementation, please refer to Figure 2 Based on the real-time position and pressure signals of the left and right pedals, left and right pedal pulse sequences are generated. The displacement change rate in the left pedal state vector is extracted. This rate is calculated by differentiating the left pedal displacement over time. The left pedal displacement change rate is compared with a preset rate threshold, and periods exceeding this threshold are marked as effective travel segments. Within these effective travel segments, the timing points where the left pedal pressure exceeds a preset start threshold are extracted. A rising pulse is generated whenever the left pedal pressure changes from below to above the preset start threshold, and a falling pulse is generated when the pressure changes from above to below the preset start threshold, thus generating a continuous left pedal pulse sequence.

[0026] The formula for calculating the rate of change of displacement of the left pedal is: in, For the first The rate of change of the left pedal displacement at each sampling time. For the first The displacement of the left pedal collected at each sampling time. For the first The displacement of the left pedal collected at each sampling time. The fixed sampling period between two adjacent sampling times. This represents the sequence number of the sampling time. The value is an integer greater than or equal to 1. The preset rate threshold is set based on the minimum speed at which the left pedal is rapidly depressed, and its value ranges from 20 mm / s to 50 mm / s. The preset start threshold is set based on the minimum force required for the left pedal to move from rest to being depressed by the operator, and its value ranges from 5 N to 15 N.

[0027] The right pedal state vector is extracted using the same method to generate a continuous right pedal pulse sequence. Specifically, the displacement change rate in the right pedal state vector is extracted, calculated by differentiating the right pedal displacement over time. This displacement change rate is compared to a preset rate threshold, and periods where the rate exceeds the threshold are marked as effective right pedal travel segments. Within these effective travel segments, the timing points where the right pedal pressure exceeds a preset start threshold are extracted, generating a continuous right pedal pulse sequence. The right pedal pulse sequence is generated in the same way as the left pedal pulse sequence, with the preset rate threshold and start threshold values ​​consistent with the corresponding parameters for the left pedal.

[0028] In addition to generating the left and right pedal pulse sequences, a synchronization check pulse is inserted into these sequences. The synchronization check pulse is a pulse with a fixed duration, inserted during the idle period between two adjacent valid pulses in the left and right pedal pulse sequences. The synchronization check pulse is generated by an internal timer of the main controller, and its insertion position is determined based on the number of pulses already generated in the pulse sequence; one synchronization check pulse is inserted every fixed number of valid pulses. The rising edge time of the synchronization check pulse is compared with a preset reference clock signal. The reference clock signal is generated by frequency division of a high-precision crystal oscillator from the main controller; the reference clock signal has a frequency of 1 kHz and a period stability of ±10 ppm. The time deviation between the rising edge of the synchronization check pulse and the nearest rising edge of the reference clock signal is calculated. When the time deviation between the synchronization check pulse and the reference clock signal exceeds a preset drift limit, a lock signal is sent to the emergency stop circuit. The preset drift limit is set based on the system clock synchronization tolerance and terminal machine response time requirements; the preset drift limit is set to 50 microseconds. Upon receiving a lockout signal, the emergency stop circuit immediately cuts off the power supply to the servo motor driver, causing the terminal block machine to stop all operations.

[0029] Example 3 In practice, the left pedal pulse sequence and the right pedal pulse sequence are compared with a preset collaborative authentication pulse table. Pulse width encoding is performed on the left pedal pulse sequence to generate a left pedal width code, and pulse width encoding is performed on the right pedal pulse sequence to generate a right pedal width code.

[0030] The process of pulse width encoding for the left pedal pulse sequence is as follows: Extract the high-level duration of each complete pulse in the left pedal pulse sequence. Round the high-level duration to a preset width quantization unit to obtain the left pedal pulse width quantization value sequence. The preset width quantization unit is set to 100 microseconds based on the minimum resolution of the terminal block controller's timer. Arrange the left pedal pulse width quantization value sequence sequentially according to the pulse occurrence time to form the left pedal width code. The left pedal width code is a one-dimensional numerical sequence, where each element corresponds to a left pedal pulse width quantization value.

[0031] The process of pulse width encoding for the right pedal pulse sequence is as follows: Extract the high-level duration of each complete pulse in the right pedal pulse sequence; round the high-level duration to a preset width quantization unit to obtain a right pedal pulse width quantization value sequence. Arrange the right pedal pulse width quantization value sequence sequentially according to the pulse occurrence time to form the right pedal width code. The right pedal width code is a one-dimensional numerical sequence, where each element corresponds to a right pedal pulse width quantization value.

[0032] Extract the phase difference between the left pedal width code and the right pedal width code. The phase difference refers to the offset of corresponding pulses in the left and right pedal pulse sequences on the time axis. The specific method for extracting the phase difference is as follows: Record the rising edge of the first pulse in the left pedal pulse sequence as the left pedal start time, and record the rising edge of the first pulse in the right pedal pulse sequence as the right pedal start time. The phase difference between the left and right pedal width codes is calculated using the following formula: in, This represents the phase difference between the left pedal width code and the right pedal width code, in milliseconds. This refers to the rising edge time of the first pulse in the left pedal pulse sequence. This refers to the rising edge of the first pulse in the right pedal pulse sequence. When the value is positive, it indicates that the right pedal pulse sequence leads the left pedal pulse sequence; when... When the value is negative, it indicates that the left pedal pulse sequence leads the right pedal pulse sequence.

[0033] The preset collaborative authentication pulse table is stored in the non-volatile memory of the terminal block main controller. The collaborative authentication pulse table contains multiple records, each containing an allowed phase difference range. The allowed phase difference range is defined by a lower allowed phase difference limit and an upper allowed phase difference limit. In a specific implementation, the lower allowed phase difference limit is set to -80 milliseconds, and the upper allowed phase difference limit is set to +80 milliseconds.

[0034] The calculated phase difference Compare with the allowed phase difference range recorded in the collaborative authentication pulse table. When the phase difference... The value is greater than or equal to the lower limit of the allowable phase difference, and the phase difference When the value is less than or equal to the upper limit of the allowed phase difference, the pulse sequence is considered to be successfully matched. The value is less than the lower limit of the allowable phase difference, or the phase difference When the value exceeds the upper limit of the allowed phase difference, the pulse sequence matching is deemed to have failed. If the pulse sequence matching is deemed successful, the terminal block machine main controller will set the matching success flag to a valid state for use by subsequent stamping enable logic. If the pulse sequence matching is deemed to have failed, the terminal block machine main controller will clear the matching success flag and disable the output of the stamping enable signal.

[0035] Example 4 In specific implementation, when the intersection region of the left pedal pulse sequence and the right pedal pulse sequence is located within a predetermined safe area, the terminal block machine's stamping enable lock is activated. The overlap interval between the left and right pedal pulse sequences on the time axis is calculated. The time range occupied by the left pedal pulse sequence on the time axis is defined by the rising edge of the first pulse and the falling edge of the last pulse in the left pedal pulse sequence. The time range occupied by the right pedal pulse sequence on the time axis is defined by the rising edge of the first pulse and the falling edge of the last pulse in the right pedal pulse sequence. The start and end times of the left and right pedal pulse sequences are extracted. The start time of the overlap interval is the later of the start times of the left and right pedal pulse sequences. The end time of the overlap interval is the earlier of the end times of the left and right pedal pulse sequences. When the start time of the overlap interval is less than the end time of the overlap interval, a valid overlap interval exists between the left and right pedal pulse sequences on the time axis.

[0036] The start and end times of the overlapping intervals are determined by the following formulas: in, This represents the starting time of the overlapping interval. This represents the end time of the overlapping interval. This refers to the rising edge time of the first pulse in the left pedal pulse sequence. This refers to the falling edge time of the last pulse in the left pedal pulse sequence. This is the rising edge time of the first pulse in the right pedal pulse sequence. This is the falling edge time of the last pulse in the right pedal pulse sequence. The function represents taking the maximum value between two time points. The function represents the minimum value between two time points. The starting time of the overlapping interval. End time of overlapping intervals The unit for all values ​​is milliseconds.

[0037] The system determines whether all time points corresponding to the overlapping intervals fall within the duration of the low-risk zone. The duration of the low-risk zone is defined by its start and end times. The start time of the low-risk zone is when the infrared grid scan detects that the operator's insertion depth is less than a preset first threshold, and the end time is when the operator's insertion depth no longer meets the low-risk zone condition. The start and end times of the low-risk zone are recorded and updated in real time by the infrared grid scanning system. The start and end times of the overlapping intervals are then compared with the start and end times of the low-risk zone.

[0038] In practice, when the start time of the overlapping interval is later than the start time of the low-risk zone, and the end time of the overlapping interval is earlier than the end time of the low-risk zone, it is determined that all time points corresponding to the overlapping interval fall within the duration of the low-risk zone. When the start time of the overlapping interval is earlier than the start time of the low-risk zone, or the end time of the overlapping interval is later than the end time of the low-risk zone, it is determined that not all time points corresponding to the overlapping interval fall within the duration of the low-risk zone.

[0039] When all time points corresponding to the overlapping intervals fall within the duration of the low-risk zone, an overlapping interval compliance flag is output. The overlapping interval compliance flag is a digital logic signal; a high level indicates compliance, and a low level indicates non-compliance. The overlapping interval compliance flag is used as one of the trigger conditions for the stamping enable lock. Other trigger conditions for the stamping enable lock include a valid pulse sequence matching flag and the absence of any emergency stop signal.

[0040] If the entire overlapping interval falls within the duration corresponding to the low-risk zone, a high-level enable signal is output to the stamping enable lock. The high-level enable signal has a voltage amplitude of 24 volts DC and a current driving capability of not less than 100 mA. After receiving the high-level enable signal, the stamping enable lock activates its internal relay, connecting the enable circuit of the servo motor driver.

[0041] In some embodiments, determining whether the time points corresponding to the overlapping intervals all fall within the duration of the low-risk zone is achieved in the following way: The start time of the overlapping interval... The start of the low-risk zone Perform numerical comparisons and determine the end times of the overlapping intervals. End of low-risk zone Perform numerical comparisons. At the start time of the overlapping interval... Numerically greater than the start time of the low-risk zone And the end time of the overlapping interval Numerically smaller than the end time of the low-risk zone At that time, the valid level of the overlapping interval compliance flag is output. This occurs at the start time of the overlapping interval. The numerical value is less than or equal to the start time of the low-risk zone. or the end time of the overlapping interval The numerical value is greater than or equal to the end time of the low-risk zone. When this occurs, the overlapping interval compliance flag is set to an invalid level. The overlapping interval compliance flag is stored in the status register of the terminal machine main controller for subsequent logic judgment circuits to read.

[0042] See Figure 3 In the graph, the horizontal axis represents the event sequence number, and the vertical axis represents the time margin, in milliseconds. The blue solid line represents the time margin on the left, the orange dashed line represents the time margin on the right, and the gray dashed line represents the zero boundary. The left-side time margin curve fluctuates around the zero boundary within the event sequence number range of 0 to 600, with the vast majority of time margin values ​​concentrated within ±100 milliseconds. A few fluctuations exceed this range, indicating that the time synchronization of the left pedal pulse sequence is generally relatively stable. The right-side time margin curve exhibits significantly greater fluctuations than the left, with time margin values ​​distributed between approximately -250 milliseconds and 500 milliseconds, and frequent large positive offsets, indicating that the time fluctuations of the right pedal pulse sequence are more drastic.

[0043] The two time margin curves in the figure show obvious overlapping fluctuations, reflecting dynamic changes in the time synchronization of the left and right pedal pulse sequences. Referring to Example 4, this figure illustrates the time margin status of the overlapping interval between the left and right pedal pulse sequences on the time axis, used to determine whether the overlapping interval falls entirely within the predetermined duration of the low-risk safety zone. The left-side time margin fluctuation is smaller and mostly concentrated near zero, indicating that the start and end points of the left pedal pulse sequence are relatively stable; while the right-side time margin fluctuation is larger, which may lead to a significant deviation between the start and end times of the overlapping interval and the left-side pulse time.

[0044] According to the judgment criteria in Example 4, the start and end times of the overlapping interval must be between the start and end times of the low-risk zone, and the pulse time margins on both sides should be maintained within a reasonable range. In the figure, the blue curve maintains a time margin within ±100 milliseconds for most of the time, meeting the requirement of an allowable phase difference of ±80 milliseconds, supporting the compliant judgment of the overlapping interval; however, the orange curve frequently shows positive peaks greater than 100 milliseconds, indicating that the right pedal pulse sequence may sometimes deviate from the safe time window, suggesting further verification to ensure that it all falls within the duration of the low-risk zone. The zero boundary line is the judgment benchmark; a positive time margin indicates that the pulse sequence time lags behind the benchmark start point, while a negative margin indicates that it is ahead.

[0045] Example 5 In practice, the servo motor driver of the terminal machine is controlled by a stamping enable lock to execute the corresponding stamping action. A high-level enable signal output from the stamping enable lock is input to the enable port of the servo motor driver. The high-level enable signal output by the stamping enable lock is a 24-volt DC voltage signal. After the enable port of the servo motor driver receives the high-level enable signal, the internal power stage circuit of the servo motor driver enters the ready state, and the servo motor releases the brake lock.

[0046] With the servo motor driver enabled, the current pressure signals of the left and right pedals are read. The current pressure signal of the left pedal is acquired in real time by a piezoelectric force sensor built into the left pedal, and the current pressure signal of the right pedal is acquired in real time by a piezoelectric force sensor built into the right pedal. Both the left and right pedal pressure signals are output in analog voltage form, converted into digital quantities by an analog-to-digital converter, and then sent to the terminal block main controller. The acceleration curve slope of the servo motor is allocated according to the pressure ratio of the current pressure signals of the left and right pedals.

[0047] The acceleration curve slope refers to the rate at which the speed of a servo motor changes over time as it accelerates from a standstill to the target speed. The specific method for allocating the acceleration curve slope of a servo motor is as follows: calculate the sum of the current pressure values ​​of the left and right pedals, calculate the proportion of the current pressure value of the left pedal to the total pressure value, and calculate the proportion of the current pressure value of the right pedal to the total pressure value. The servo motor acceleration curve slope is determined by the following formula: in, This represents the slope of the acceleration curve of the servo motor, expressed in revolutions per minute per second. Basic acceleration slope, basic acceleration slope The setting is 600 revolutions per minute per second, and the base acceleration slope is... The settings are based on the terminal block machine servo motor's rated speed of 3000 rpm and the recommended acceleration time from standstill to rated speed of 5 seconds. This is the current pressure value of the left pedal, in Newtons. This shows the current pressure value of the right pedal, in Newtons. The current pressure value of the left pedal... The value ranges from 0 Newtons to 200 Newtons, representing the current pressure value of the right pedal. The value ranges from 0 Newtons to 200 Newtons. When the current pressure value of the left pedal... Current pressure value of the right pedal When both are 0 Newtons, the denominator is 0, and the slope of the acceleration curve is... If the value is set to 0, the servo motor will not perform acceleration.

[0048] After assigning the acceleration curve slope to the servo motor, the servo motor is driven to perform a pressing action based on the acceleration curve slope. The servo motor driver receives the acceleration curve slope parameter and generates a speed curve according to the acceleration curve slope. The speed curve linearly increases the servo motor speed on the time axis with the acceleration curve slope as the rate of change, until the servo motor speed reaches the preset target speed. The preset target speed is set according to the terminal block stamping process requirements, and the preset target speed is set to 2000 rpm. The servo motor drives the crank-connecting rod mechanism to move the stamping die downwards, performing the pressing action. During the pressing action, the terminal block machine main controller continuously monitors the cumulative displacement values ​​of the left pedal and right pedal, as well as the operator's hand insertion depth obtained by infrared grid scanning. The servo motor continues to run until it reaches the predetermined stroke end point. The predetermined stroke end point is determined by the position value fed back by the servo motor encoder, and the predetermined stroke end point corresponds to the position where the stamping die is fully closed. After reaching the predetermined stroke end point, the servo motor driver controls the servo motor to rotate in the opposite direction, driving the stamping die back to the initial position.

[0049] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A dual-pedal control method for improving the operational safety of a terminal block machine, characterized in that, The method includes: Acquire the real-time position and pressure signals of the left and right pedals on the operating side; The infrared grid distribution map of the terminal block machine's working area is collected, and the infrared grid map is divided into multiple safety zones; Based on the real-time position and pressure signals of the left and right pedals, a left pedal pulse sequence and a right pedal pulse sequence are generated. The left pedal pulse sequence and the right pedal pulse sequence are compared with a preset collaborative authentication pulse table; When the intersection area of ​​the left pedal pulse sequence and the right pedal pulse sequence is located in a predetermined safe area, the terminal machine's stamping enable lock is activated. The servo motor driver of the terminal machine is controlled by the stamping enable lock to execute the corresponding stamping action.

2. The dual-pedal control method for improving the operational safety of a terminal block machine according to claim 1, characterized in that, The acquisition of real-time position and pressure signals of the left and right pedals on the operating side specifically includes: The displacement of the pedals is continuously collected by the magnetic displacement sensors built into the left and right pedals. The pedal pressure is collected synchronously by the piezoelectric force sensors built into the left and right pedals. Align the pedal force and pedal displacement according to the timestamp to generate the left pedal state vector and the right pedal state vector.

3. The dual-pedal control method for improving the operational safety of a terminal block machine according to claim 2, characterized in that, The infrared grid distribution map of the terminal machine's working area is collected, and the infrared grid map is divided into multiple safe zones, specifically including: Control the horizontal infrared emitter and the vertical infrared receiver to scan and obtain the occlusion matrix of the working area; The insertion position and depth of the operator's hand are identified based on the number of consecutive dark spots in the occlusion matrix. The area with a penetration depth less than a preset first threshold is marked as a low-risk area, and the area with a penetration depth greater than a preset second threshold is marked as a high-risk area.

4. The dual-pedal control method for improving the operational safety of a terminal block machine according to claim 3, characterized in that, The step of generating a left pedal pulse sequence and a right pedal pulse sequence based on the real-time position and pressure signals of the left and right pedals specifically includes: Extract the displacement change rate from the left pedal state vector and mark the time period when the displacement change rate exceeds the preset rate threshold as the effective travel segment of the left pedal; Within the effective travel range of the left pedal, the timing points where the pedaling force exceeds the preset start threshold are extracted, and a continuous left pedal pulse sequence is generated. The right pedal state vector is extracted using the same method to generate a continuous right pedal pulse sequence.

5. A dual-pedal control method for improving the operational safety of a terminal block machine according to claim 4, characterized in that, The step of comparing the left pedal pulse sequence and the right pedal pulse sequence with a preset collaborative authentication pulse table specifically includes: The pulse width encoding is performed on the left pedal pulse sequence and the right pedal pulse sequence respectively to generate the left pedal width code and the right pedal width code; Extract the phase difference between the left pedal width code and the right pedal width code; When the phase difference falls within the allowed phase difference range recorded in the collaborative authentication pulse table, the pulse sequence is determined to be successfully matched.

6. A dual-pedal control method for improving the operational safety of a terminal block machine according to claim 5, characterized in that, The step of activating the terminal block machine's punching enable lock when the intersection region of the left pedal pulse sequence and the right pedal pulse sequence is located within a predetermined safe area specifically includes: Calculate the overlap interval between the left pedal pulse sequence and the right pedal pulse sequence on the time axis; Determine whether all the time points corresponding to the overlapping intervals fall within the duration of the low-risk zone; If the entire overlapping interval falls within the duration corresponding to the low-risk zone, a high-level enable signal is output to the stamping enable lock.

7. A dual-pedal control method for improving the operational safety of a terminal block machine according to claim 6, characterized in that, The servo motor driver of the terminal machine controlled by the stamping enable lock executes the corresponding stamping action, specifically including: The high-level enable signal output by the stamping enable lock is input to the enable port of the servo motor driver; Read the current pressure signals of the left pedal and the right pedal, and allocate the acceleration curve slope of the servo motor according to the pressure ratio; The servo motor is driven to perform a downward pressing action according to the slope of the acceleration curve until the predetermined end point of the stroke is reached.

8. A dual-pedal control method for improving the operational safety of a terminal block machine according to claim 1, characterized in that, The method of acquiring the real-time position and pressure signals of the left and right pedals on the operating side also includes: The displacements of the left and right pedals are respectively differentially calculated with their respective previous sampled values ​​to obtain the instantaneous displacement increments; The instantaneous displacement increments are accumulated to obtain the cumulative displacement value; When the cumulative displacement value exceeds the preset maximum safe stroke, the control circuit of the stamping enable lock is forcibly cut off.

9. A dual-pedal control method for improving the operational safety of a terminal block machine according to claim 4, characterized in that, The generation of the left pedal pulse sequence and the right pedal pulse sequence further includes: A synchronization check pulse is inserted into the pulse sequences of the left and right pedals; The synchronization verification pulse is compared with a preset reference clock signal; When the deviation between the synchronization verification pulse and the reference clock signal exceeds a preset drift limit, a lock signal is sent to the emergency stop circuit.

10. A dual-pedal control method for improving the operational safety of a terminal block machine according to claim 6, characterized in that, The determination of whether the time points corresponding to the overlapping intervals all fall within the duration of the low-risk zone specifically includes: The start and end times of the overlapping interval are compared with the start and end times of the low-risk zone, respectively. When the start time of the overlapping interval is later than the start time of the low-risk zone and the end time of the overlapping interval is earlier than the end time of the low-risk zone, the compliance flag bit of the overlapping interval is output, and the compliance flag bit is used as one of the triggering conditions of the stamping enable lock.

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