A low-temperature interference-resistant electric leg self-adaptive touch ground detection method and system

Abstract

The application discloses a kind of anti-low temperature interference electric leg self-adapting touch ground detection method and system.The method includes: the sliding mean filtering of real-time current obtains If;In the adaptive learning stage of the initial stage of leg deployment, based on filter current If, establish and real-time tracking reference baseline Bref reflecting current environmental resistance;After the journey reaches the preset locking position, stop updating and solidify the value of Bref as dynamic zero reference value Bsolid;The difference Diff of If and Bsolid is calculated, if Diff continuously meets preset increment threshold, then count, if any sampling point does not meet halfway, then execute hard clear zero to counter;When counter reaches preset time verification threshold, determine touch ground and output stop signal.The application solves the problem of false triggering caused by background current drift and noise burr in low temperature environment through three-stage logic of adaptive learning-baseline locking-hard clear zero continuous confirmation, without historical calibration, with very high environmental robustness and detection reliability.

Description

Technical Field

[0001] This invention relates to the field of leveling and support technology for special vehicles, specifically to a method and system for detecting the ground contact of electric outriggers that can achieve adaptive sensing under low temperature and complex load variation conditions. Background Technology

[0002] Currently, electric outriggers are widely used in special vehicles, construction machinery, fire trucks, and aerial work platforms. As a support unit for special vehicles and mobile construction machinery, the reliability of the outrigger's ground contact detection directly determines the system's automation level and operational safety. Accurate ground contact detection ensures that the outrigger stops extending in time, avoiding problems such as lower limit collisions and outrigger damage caused by over-extension.

[0003] Existing current-based ground contact detection technologies (such as patent CN116465288A with application number 202310605351.4) typically rely on recording the current of the outrigger throughout its entire stroke or comparing historical no-load data, which has the following significant limitations:

[0004] (1) Environmental temperature sensitivity: In low-temperature environments (such as -30℃), the viscosity of the grease in the reduction gear increases, and the no-load background current (baseline current) may surge from 2A at room temperature to over 4A. If a fixed threshold or inaccurate historical reference is used, it is very easy to cause false triggering or detection failure.

[0005] (2) Dynamic noise interference: Uneven mechanical friction at low temperatures can cause severe high-frequency spikes in the current waveform. Conventional single filters often cannot balance real-time performance and false alarm prevention.

[0006] (3) Gentle ground contact characteristics: In the auxiliary support scenario where the tire does not leave the ground, the increase in current at the moment of ground contact is small and the upward slope is gentle, making it easy to be submerged in the fluctuating background current.

[0007] (4) Strong dependence on historical data: Multiple thresholds need to be recalibrated after first use or repair, resulting in poor adaptability; the single threshold judgment strategy is easily affected by instantaneous current spikes (PWM ripple, sampling noise) and may cause false triggering.

[0008] The core difference between this invention and CN116465288A is that: (1) a dynamic baseline self-learning and locking mechanism is used instead of a fixed threshold or full-process recording method, which does not require historical calibration data; (2) a hard zero counter verification mechanism is used to fundamentally eliminate the risk of false triggering caused by the gradual accumulation of instantaneous interference; (3) a relative incremental judgment strategy based on dynamic zero point is adopted, and the ground contact judgment threshold Td only needs to be calibrated once at the factory, which can be stable and effective in the entire temperature range, and completely eliminate the influence of temperature drift on the judgment benchmark.

[0009] Therefore, a detection logic is needed that does not rely on historical data, can adapt to environmental resistance in real time, and can accurately identify true and false ground contact signals. Summary of the Invention

[0010] One objective of this invention is to provide an adaptive ground contact detection method for electric outriggers that is resistant to low-temperature interference. Based on a three-stage detection logic of "real-time adaptive learning and solidification of background characteristics" and "continuous verification with hard reset in the time domain", this method aims to solve the problem that existing technologies cannot work stably under significant environmental changes.

[0011] The technical solution to achieve the above objective is: an adaptive ground contact detection method for an electric outrigger resistant to low-temperature interference, characterized by comprising the following steps:

[0012] S1: Real-time acquisition of the current sampling value of the outrigger motor driver, and time-domain smoothing filtering processing to obtain the real-time filtered current If;

[0013] S2: During the background load characteristic acquisition phase of the outrigger extension stroke, the reference baseline Bref is updated in real time according to If, so that it dynamically tracks the background current generated by the current environment and mechanical resistance.

[0014] S3: When the outrigger travels to the preset solidified boundary point, stop updating the reference baseline Bref and lock the current value as the dynamic zero-point reference value Bsolid for this testing cycle;

[0015] S4: Calculate the current difference Diff between the current filter current If and the dynamic zero-point reference value Bsolid in real time;

[0016] S5: Compare the difference Diff with the preset ground contact determination increment threshold Td: if Diff ≥ Td, the ground contact confirmation counter Count is incremented; if Diff < Td, the counter Count is immediately hard-cleared and the confirmation counting restarts.

[0017] S6: When the counter Count continuously accumulates to the preset threshold of continuous valid sampling points Tconfirm, it is determined that the outrigger touches the ground and a stop signal is output; the valid sampling point is the current sampling point that satisfies Diff≥Td.

[0018] Furthermore, in step S1, the time-domain smoothing filter adopts a sliding window mean filtering algorithm, and the time range corresponding to the window length is 5ms to 20ms.

[0019] Furthermore, in step S2, the update of the reference baseline Bref employs a first-order low-pass filtering algorithm:

[0020] Bref(n) = Bref(n-1) + α × (If(n) - Bref(n-1))

[0021] Where n is the sampling time number and n-1 is the previous sampling time number.

[0022] Furthermore, in step S3, the preset curing boundary point is set within the safe travel range before the expected ground contact area of ​​the outrigger; specifically, the travel position corresponding to the curing boundary point is not less than 55% and not more than 70% of the total travel of the outrigger.

[0023] Furthermore, the specific method for determining the filter coefficient α is as follows: obtain the factory-calibrated peak-to-peak value of the no-load current pre-stored in the non-volatile memory of the microprocessor. When the peak-to-peak value of the no-load current does not exceed 5% of the rated current of the outrigger motor, take α = 0.006~0.010; when the peak-to-peak value of the no-load current exceeds 5% of the rated current of the outrigger motor, take α = 0.001~0.005.

[0024] The preset ground contact determination increment threshold Td is pre-stored in the microprocessor's non-volatile memory, and its acquisition method includes the following calibration steps:

[0025] During the equipment factory calibration phase, the electric outriggers are controlled to extend downwards under no-load conditions. The motor drive current value is sampled and obtained through the current detection circuit of the outrigger motor driver, and recorded as the no-load current I_empty.

[0026] When the electric outrigger continues to extend until its end contacts the support surface and the outrigger reaches the ground support force required for the target operation, the motor drive current value at this time is sampled by the current detection circuit and recorded as the required ground contact current I_touch.

[0027] Calculate the difference between the required ground contact current and the no-load current to obtain the ground contact determination increment threshold:

[0028] Td=I_touch-I_empty

[0029] The difference is solidified and written into the microprocessor memory as the current increment threshold for determining the outrigger contact with the ground during subsequent operation; the preset ground contact determination increment threshold Td remains a fixed calibration value during the operation of the whole machine.

[0030] Furthermore, in step S5, the hard reset strategy for the counter Count is as follows: when any single sampling point satisfies Diff < Td, Count is immediately reset to zero; the hard reset strategy ensures that only real ground contact signals with current continuously and stably exceeding the threshold can be accumulated to the number of consecutive sampling points corresponding to Tconfirm, avoiding false alarms caused by the continuous accumulation of instantaneous spikes.

[0031] Furthermore, in step S6, the threshold for consecutive valid sampling points, Tconfirm, is 5 to 30.

[0032] Another object of the present invention is to provide an adaptive ground contact detection system for electrically powered outriggers resistant to low-temperature interference, comprising:

[0033] The current detection circuit is integrated into the control unit built into the outrigger motor driver. The control unit is equipped with a microprocessor, and the output signal terminal of the current detection circuit is electrically connected to the microprocessor through an analog-to-digital converter module. The current detection circuit is used to sample the drive current of the outrigger motor driver and convert it into a digital signal that can be received and processed by the microprocessor through analog-to-digital conversion.

[0034] Current acquisition, control and filtering unit: controls the current detection circuit to acquire the drive current at a preset sampling period, performs time-domain smoothing filtering on the acquired data, and outputs the real-time filtered current If;

[0035] Baseline self-learning unit: During the background characteristic acquisition stage of outrigger extension, it receives the filtered current If and executes a first-order low-pass filter update algorithm to maintain and output the reference baseline Bref in real time;

[0036] Baseline locking unit: Receives travel information output by encoder or counter. When the travel reaches the preset fixed boundary point, it sends a stop update command to the baseline self-learning unit and latches the current Bref as the dynamic zero-point reference value Bsolid.

[0037] Difference Calculation Unit: Calculates the difference between If and Bsolid (Diff) in real time and outputs it to the decision unit;

[0038] Ground contact logic determination unit: compares Diff with the ground contact determination increment threshold Td and counts using the ground contact confirmation counter Count. If Diff ≥ Td, the ground contact confirmation counter Count is incremented. If Diff < Td, the counter Count is immediately hard-cleared and the confirmation counting restarts. When the ground contact confirmation counter Count continuously increments to reach the preset continuous valid sampling point threshold Tconfirm, the leg is determined to be in contact with the ground and a stop signal is output. The valid sampling point is the current sampling point that satisfies Diff ≥ Td.

[0039] This invention is applicable to equipment that is supported on the ground by a combination of tires and outriggers during operation.

[0040] This invention does not preset a fixed current threshold. Instead, within the safe travel range of the outrigger extension, it utilizes the motor's own no-load operating state as an environmental sensing "sensor" to detect and learn the current background current in real time. This means that a real-time reference baseline is automatically established at the initial stage of each outrigger deployment to eliminate the influence of temperature. By locking the Bref to Bsolid before entering the ground contact detection zone, a pure "dynamic zero point" is obtained. Based on this, a rigorous confirmation mechanism of "immediate hard zeroing if the standard is not met" is used to completely filter out instantaneous spikes, responding only to genuine ground contact signals with a trend of increasing intensity.

[0041] The present invention has the following advantages over the prior art:

[0042] (1) No historical calibration required: The outriggers automatically learn the current background each time they are deployed, adapting to the scenarios of first use and after maintenance;

[0043] (2) Strong low temperature robustness: Baseline dynamic tracking eliminates background current drift caused by temperature, and can work stably from -30℃ to room temperature;

[0044] (3) High anti-burst capability: The hard zeroing mechanism ensures that the confirmation count is reset as soon as any single sampling fails to meet the standard, thus eliminating the accumulation of false alarms due to dense interference;

[0045] (4) Stable and effective threshold: The fixed incremental threshold Td is determined based on the relative increment and is not affected by the absolute value of the background current. It does not need to be adjusted with temperature or load changes.

[0046] (5) Simple implementation: All logic is completed within the 1ms timer interrupt of the embedded control, which is suitable for resource-constrained embedded controllers. Attached Figure Description

[0047] Figure 1 This is a software flowchart of the present invention; Figure 2 The waveform diagram of the outrigger motor drive current under normal temperature conditions;

[0048] Figure 3 Waveform of the outrigger motor drive current under -30℃ low temperature conditions;

[0049] Figure 4 This is a timing diagram of the current sampling waveform and ground contact determination logic for the first application example;

[0050] Figure 5 for Figure 4 Enlarged view of part A in the middle;

[0051] Figure 6 This is a schematic diagram of the grounding confirmation count value change curve for the hard reset counter strategy in the first application example (low temperature condition, dense burrs). Figure 7This is a timing diagram of the current sampling waveform and ground contact determination logic for the second application example; Figure 8 for Figure 7 Enlarged view of part A in the middle; Figure 9 This is a schematic diagram of the grounding confirmation count value change curve for the hard reset counter strategy in the second application example. Detailed Implementation

[0052] This embodiment discloses an adaptive ground contact detection system for electrically powered outriggers that is resistant to low-temperature interference, including:

[0053] The current detection circuit is integrated into the control unit built into the outrigger motor driver (i.e., the conventional configuration of existing outrigger motor drivers). The control unit is equipped with a microprocessor, and the output signal of the current detection circuit is electrically connected to the input terminal of the microprocessor through an analog-to-digital converter module. The current detection circuit is used to sample the drive current (analog signal) of the outrigger motor driver and convert it into a digital signal that can be received and processed by the microprocessor through analog-to-digital converter (ADC), so that the various software modules inside the microprocessor can call and execute the ground contact determination logic.

[0054] Current acquisition, control and filtering unit: controls the current detection circuit to acquire the drive current at a preset sampling period, performs time-domain smoothing filtering on the acquired data, and outputs the real-time filtered current If;

[0055] Baseline self-learning unit: During the background characteristic acquisition stage of outrigger extension, it receives the filtered current If and executes a first-order low-pass filter update algorithm to maintain and output the reference baseline Bref in real time;

[0056] Baseline locking unit: Receives travel information output by encoder or counter (encoder is a mature hardware configuration for outrigger motor, counter is a microprocessor built-in program counter). When the travel reaches the preset fixed boundary point, it sends a stop update command to the baseline self-learning unit and latches the current Bref as the dynamic zero-point reference value Bsolid.

[0057] Difference Calculation Unit: Calculates the difference between If and Bsolid in real time (Diff) and outputs it to the grounding logic determination unit;

[0058] Ground contact logic determination unit: compares Diff with the ground contact determination increment threshold Td and counts using the ground contact confirmation counter Count. If Diff ≥ Td, the ground contact confirmation counter Count is incremented; if Diff < Td, the counter Count is immediately hard-cleared and the confirmation counting restarts. When the ground contact confirmation counter Count continuously increments to reach the preset continuous valid sampling point threshold Tconfirm (5-30 points), the leg is determined to be in contact with the ground and a stop signal is output. The valid sampling point is the current sampling point that satisfies Diff ≥ Td.

[0059] In this application example, the current acquisition control and filtering unit, baseline self-learning unit, baseline locking unit, difference calculation unit, and ground contact logic determination unit are all integrated as software modules within the 1ms timer interrupt service routine of the microprocessor (STM32). Each unit exchanges data through global structure variables. The current acquisition control and filtering unit reads the raw ADC value and outputs If; the baseline self-learning unit and baseline locking unit maintain the Bref and Bsolid states; the difference calculation unit outputs Diff in real time; and the ground contact logic determination unit executes the counter logic and sets the stop flag when the condition is met. The longest delay time of the entire detection link is 5-30ms (Tconfirm is 5-30 times), meeting industrial-grade response requirements.

[0060] like Figure 1 As shown, this embodiment also discloses a detection method based on a low-temperature interference-resistant electric outrigger adaptive ground contact detection system, including the following steps:

[0061] S1: The microprocessor collects the current sampling value of the outrigger motor driver in real time and performs time-domain smoothing filtering to obtain the real-time filtered current If. The time-domain smoothing filtering adopts the sliding window mean filtering algorithm, and the time range corresponding to the window length is 5ms to 20ms.

[0062] S2: During the background load characteristic acquisition stage of the outrigger extension stroke, the microprocessor updates the reference baseline Bref in real time according to If, so that it dynamically tracks the background current generated by the current environment and mechanical resistance.

[0063] The baseline Bref is updated using the first-order low-pass filtering algorithm shown in Equation (1).

[0064] Bref(n) = Bref(n-1) + α × (If(n) - Bref(n-1)) (1)

[0065] Where n is the sampling time number, and n-1 is the previous sampling time number; α is the filtering coefficient, with a value range of 0.001 to 0.01; when the peak-to-peak value of the outrigger motor's no-load current does not exceed 5% of the outrigger motor's rated current, α is 0.006 to 0.010; when the peak-to-peak value of the outrigger motor's no-load current exceeds 5% of the outrigger motor's rated current, α is 0.001 to 0.005. The peak-to-peak value of the outrigger motor's no-load current is the factory calibration value pre-stored in the microprocessor's flash memory.

[0066] S3: When the outrigger travels to the preset solidification boundary point, the microprocessor stops updating the reference baseline Bref and locks the current value as the dynamic zero-point reference value Bsolid for this detection cycle.

[0067] The preset solidification boundary point is set within a safe travel range before the outrigger's expected ground contact area; specifically, the travel position corresponding to the solidification boundary point is no less than 55% and no more than 70% of the total outrigger travel. Figure 1 The example is 55%;

[0068] S4: The microprocessor calculates the current difference Diff between the current filter current If and the dynamic zero-point reference value Bsolid in real time;

[0069] S5: The microprocessor compares the difference Diff with the preset ground contact determination increment threshold Td: if Diff ≥ Td, the ground contact confirmation counter Count is incremented; if Diff < Td, the counter Count is immediately hard-cleared and the confirmation counting restarts.

[0070] The preset ground contact determination increment threshold Td is pre-stored in the microprocessor's non-volatile memory, and its acquisition method includes the following calibration steps:

[0071] During the equipment factory calibration phase, the electric outriggers are controlled to extend downwards under no-load conditions. The motor drive current value is sampled and obtained through the current detection circuit of the outrigger motor driver, and recorded as the no-load current I_empty.

[0072] When the electric outrigger continues to extend until its end contacts the support surface and the outrigger reaches the ground support force required for the target operation, the motor drive current value at this time is sampled by the current detection circuit and recorded as the required ground contact current I_touch.

[0073] Calculate the difference between the required ground contact current and the no-load current to obtain the ground contact determination increment threshold:

[0074] Td=I_touch-I_empty

[0075] The difference is solidified and written into the microprocessor memory as the current increment threshold for determining the outrigger contact with the ground during subsequent operation; the preset ground contact determination increment threshold Td remains a fixed calibration value during the operation of the whole machine.

[0076] This threshold acquisition scheme requires no temperature compensation, and the same Td calibration value is applied for both normal and low temperature operating conditions. Combined with the adaptive sensing logic for background current (dynamic zero-point reference value Bsolid) of this invention, it enables the determination of ground contact characteristics based solely on the difference between two sampling points, greatly simplifying the calibration process and ensuring consistency in judgment under multiple load conditions.

[0077] S6: When the counter Count continuously accumulates to the preset threshold of continuous valid sampling points Tconfirm (5-30), it is determined that the outrigger touches the ground and a stop signal is output; the valid sampling point is the current sampling point that satisfies Diff≥Td.

[0078] The sampling period of this system is fixed at 1ms. The current is sampled once every 1ms and the difference Diff is calculated. For example, if all 10 consecutive samples within 10ms are Diff≥Td, the counter Count is incremented to 10, and the outrigger is determined to be in contact with the ground.

[0079] To further illustrate the necessity of using dynamic baseline tracking and incremental threshold determination in this application, the applicant conducted experimental analysis on the motor current characteristics under different ambient temperatures.

[0080] The invention will now be further described in conjunction with specific parameters and typical operating conditions.

[0081] Application Example 1:

[0082] 1) Application Scenarios and Environment Settings

[0083] This embodiment selects a special-purpose vehicle as the implementation object. This vehicle is equipped with four sets of electrically powered outrigger systems for vehicle leveling and support during field operations. The current environment is extremely cold: ambient temperature -30℃. Under this low-temperature environment, the viscosity of the grease in the outrigger transmission mechanism increases significantly, leading to a substantial increase in mechanical friction resistance.

[0084] 2) Hardware and Control Logic Fundamentals

[0085] This invention uses an STM32 series microcontroller as the implementation platform, with a sampling period of 1ms, and all operations are completed in the timer interrupt service routine.

[0086] 3) Specific Work Process

[0087] Step S1 Adaptive Learning and Baseline Locking Phase

[0088] After the outrigger motor starts, it enters the adaptive learning interval. The controller collects the phase current fed back by the driver at a period of 1ms, and obtains If after averaging filtering through a 10ms sliding window. The reference baseline Bref tracks If in real time using a first-order low-pass filter (α=0.008; the factory-calibrated peak-to-peak value of the no-load current at room temperature is 0.05A, and the measured peak-to-peak value under low-temperature conditions is about 0.29A. Neither of these values ​​exceeds 5% of the rated current of 8A, i.e., 0.4A. According to claim 5, the higher value α=0.008 is adopted).

[0089] As shown in Figure 3, under low temperature conditions of -30℃, the viscosity of the lithium-based grease used with the outrigger motor increases significantly, reaching a kinematic viscosity of over 800 mm² / s at -30℃. Due to the high viscosity lubrication resistance, the motor's no-load current remains stable at around 4.2A. Analyzing the curves in Figure 3: Line A is the real-time tracking curve of the dynamic reference baseline Bref, and curve B is the actual current change curve of the motor during the no-load phase. The no-load current fluctuation range is 3.96A to 4.25A, with a peak-to-peak value of approximately 0.29A. The baseline self-learning algorithm of this application enables the reference baseline Bref to stably track up to 4.2A.

[0090] When the encoder count reaches the fixed boundary point (in this embodiment, it is set to 56% of the total outrigger travel, within the safety margin before the expected ground contact area), the system locks: Bsolid = 4.2A, the self-learning unit stops updating, and enters the detection phase.

[0091] Step S2 Grounding Detection and Hard Zero Verification Stage

[0092] Once in the detection zone, the system only focuses on the current increment relative to Bsolid = 4.2A. The preset increment threshold Td = 0.8A (calibrated based on the on-site load, applicable to the entire temperature range), and the continuous effective sampling point threshold Tconfirm is 10.

[0093] like Figure 4-6 As shown, under a high background of -30℃, the current waveform exhibits multiple random spikes, with some spike amplitudes exceeding the judgment threshold of 5.0A (Diff > 0.8A). After the spikes disappear, the current drops back to around 4.2A (Diff < Td).

[0094] Hard reset logic: Count is immediately reset to zero after the spike ends, and it must be accumulated again for 10 times before it can be triggered. The spike cannot cause false alarms.

[0095] After the outrigger contacts the ground, the current continuously rises to 5.018A (Diff = 5.018 - 4.2 = 0.818A ≥ Td = 0.8A), and Count continuously increases to 10 within 10ms (Tconfirm is set to 10 in this application example). The system outputs a ground contact stop signal, as detailed below. Figure 6 As shown.

[0096] In this application example, the process of obtaining the preset incremental threshold Td = 0.8A is as follows:

[0097] During the equipment commissioning and calibration phase, the microprocessor reads current data in real time through the current sampling channel of the outrigger motor driver. First, the outrigger is controlled to extend under no-load conditions, and the no-load current I_empty during the stable operation phase is acquired and recorded, which is found to be 2.137A.

[0098] The outriggers are then controlled to extend further until they contact the ground. When the system confirms that the outriggers have achieved the support force required for the current application scenario (the monitoring of outrigger load-bearing pressure is existing technology, and the specific principle is the same as that of electronic scales, as disclosed in Chinese patents CN 202989909 U and CN 108248567 A, which will not be elaborated here), the microprocessor samples again through the current sampling circuit, obtains and records the required ground contact current I_touch at this time, and measures I_touch = 2.937A.

[0099] According to the formula Td = I_touch - I_empty, we can calculate Td = 2.937A - 2.137A = 0.8A.

[0100] The value of Td = 0.8A is written into memory as a fixed calibration parameter. During subsequent operation, regardless of whether the system is at room temperature (25°C) or low temperature (-30°C), this fixed threshold is directly used to determine whether Diff ≥ Td, without requiring any additional temperature compensation algorithm for Td. The changes in background drag caused by different temperatures are absorbed by the adaptively learned Bsolid, thus ensuring the high reliability of the single threshold Td across the entire temperature range.

[0101] Application Example 2

[0102] 1) Application Scenarios and Environment Settings

[0103] This embodiment uses the special-operation vehicle described in Application Example 1 as the implementation object. The current environment is normal temperature operating conditions: the ambient temperature is about 25°C, the viscosity of the lubricating grease is within the normal range, and the mechanical friction resistance is normal.

[0104] 2) Hardware and Control Logic Fundamentals

[0105] Same as application example one.

[0106] 3) Specific Work Process

[0107] Step S1 Adaptive Learning and Baseline Locking Phase

[0108] After the outrigger motor starts, it enters the adaptive learning interval. The controller collects the phase current fed back by the driver at a period of 1ms, and obtains If after averaging through a 10ms sliding window. The reference baseline Bref tracks If in real time using a first-order low-pass filter (α=0.008).

[0109] like Figure 2 As shown, under normal temperature conditions, the motor's no-load current remains stable around 2.137A. Line A represents the real-time tracking curve of the dynamic reference baseline Bref, while curve B represents the actual current change curve of the motor during the no-load phase. The current fluctuation amplitude during the no-load phase is significantly smaller than that under low temperature conditions (peak-to-peak value approximately 0.05A). The baseline learning algorithm stabilizes Bref at 2.137A. Figure 7 , 8 (Illustrated by 2.0A).

[0110] When the encoder count reaches the solidified boundary point (in this embodiment, it is also set to 56% of the total outrigger stroke), the system locks: Bsolid = 2.137A, the self-learning unit stops updating, and enters the detection phase.

[0111] Step S2 Grounding Detection and Hard Zero Verification Stage

[0112] Once in the detection zone, the system only focuses on the current increment relative to Bsolid = 2.137A. Figure 7 , 8 (Illustrated with 2.0A). The preset incremental threshold Td = 0.8A (same as application example one, fixed calibration value), and Tconfirm is 10.

[0113] like Figure 7-9 As shown, under normal operating conditions, the burr amplitude is small and sparse. When the burr amplitude is small (Diff < Td), the Count immediately returns to zero and no false alarm is generated.

[0114] When the outrigger touches the ground, the current continues to rise to 2.977A (Diff = 2.977 - 2.137 = 0.840A ≥ Td = 0.8A), and Count continuously increases to 10 within 10ms (Tconfirm is set to 10 in this application example), and the system outputs a ground contact stop signal.

[0115] As a further illustration of the present invention, through comparison Figure 2 and Figure 3 It can be seen that:

[0116] If a fixed absolute current threshold (e.g., 3A) is used for judgment in existing technology, although it may barely work at room temperature, at a low temperature of -30℃, the baseline current (4.202A) alone will far exceed this fixed threshold. This will directly lead to serious false alarms in the system at the moment of power-on or in the early stage of operation, that is, the system will incorrectly determine that the outrigger has touched the ground and stopped extending.

[0117] This application tracks the baseline current (Bref) in real time and locks it as a dynamic zero point (Bsolid), then calculates the incremental threshold (Td) based on the baseline. This approach effectively eliminates the influence of DC component drift caused by temperature. Regardless of whether the baseline is 2.137A or 4.202A, the algorithm always focuses on the "amplitude of the change relative to the current baseline"—the ground contact increment is 0.840A and 0.816A under the two operating conditions, respectively, showing a high degree of consistency and indicating that this algorithm has a natural adaptive capability to temperature changes. Combined with the aforementioned hard zeroing strategy, this scheme ensures that ground contact detection still has extremely high accuracy and reliability under the full temperature range (especially low temperature and high impedance) conditions.

Claims

1. A method for adaptive ground contact detection of an electrically powered outrigger resistant to low-temperature interference, characterized in that, Includes the following steps: S1: Real-time acquisition of the current sampling value of the outrigger motor driver, and time-domain smoothing filtering processing to obtain the real-time filtered current If; S2: During the background load characteristic acquisition stage of the outrigger extension stroke, the reference baseline Bref is updated in real time according to If, so that Bref dynamically tracks the background current generated by the current environment and mechanical resistance; S3: When the outrigger travels to the preset solidified boundary point, stop updating the reference baseline Bref and lock the current value as the dynamic zero-point reference value Bsolid for this detection cycle; S4: Calculate the current difference Diff between the current filter current If and the dynamic zero-point reference value Bsolid in real time; S5: Compare the difference Diff with the preset ground contact determination increment threshold Td: if Diff ≥ Td, the ground contact confirmation counter Count is incremented; if Diff < Td, the counter Count is immediately hard-cleared and the confirmation counting restarts. S6: When the counter Count continuously accumulates to the preset threshold of continuous valid sampling points Tconfirm, it is determined that the outrigger has touched the ground and a stop signal is output; the valid sampling point is the current sampling point that satisfies Diff≥Td.

2. The method according to claim 1, characterized in that: In step S1, the time-domain smoothing filter adopts the sliding window mean filtering algorithm, and the time range corresponding to the window length is 5ms to 20ms.

3. The method according to claim 1, characterized in that: In step S2, the update of the reference baseline Bref uses a first-order low-pass filtering algorithm: Bref(n) = Bref(n-1) + α × (If(n) - Bref(n-1)) Where n is the sampling time number, n-1 is the previous sampling time number; α is the filtering coefficient, with a value range of 0.001 to 0.

01.

4. The method according to claim 1, characterized in that: In step S3, the preset curing boundary point is set within the safe travel range before the expected ground contact area of ​​the outrigger; specifically, the travel position corresponding to the curing boundary point is not less than 55% and not more than 70% of the total travel of the outrigger.

5. The method according to claim 3, characterized in that: The specific method for determining the filter coefficient α is as follows: obtain the factory-calibrated peak-to-peak value of the no-load current pre-stored in the non-volatile memory of the microprocessor. When the peak-to-peak value of the no-load current does not exceed 5% of the rated current of the outrigger motor, take α = 0.006~0.01; when the peak-to-peak value of the no-load current exceeds 5% of the rated current of the outrigger motor, take α = 0.001~0.

005.

6. The method according to claim 1, characterized in that: In step S5, the hard reset strategy for the counter Count is as follows: when any single sampling point satisfies Diff < Td, Count is immediately reset to zero; the hard reset strategy ensures that only real ground contact signals with current continuously and stably exceeding the threshold can be accumulated to the number of consecutive sampling points corresponding to Tconfirm, avoiding false alarms caused by the continuous accumulation of instantaneous glitches.

7. The method according to claim 1, characterized in that: In step S6, the threshold for consecutive valid sampling points, Tconfirm, is 5 to 30.

8. The method according to claim 1, characterized in that: The preset ground contact determination increment threshold Td is pre-stored in the microprocessor's non-volatile memory, and its acquisition method includes the following calibration steps: During the equipment factory calibration phase, the electric outriggers are controlled to extend downwards under no-load conditions. The motor drive current value is sampled and obtained through the current detection circuit of the outrigger motor driver, and recorded as the no-load current I_empty. When the electric outrigger continues to extend until its end contacts the support surface and the outrigger reaches the ground support force required for the target operation, the motor drive current value at this time is sampled by the current detection circuit and recorded as the required ground contact current I_touch. Calculate the difference between the required ground contact current and the no-load current to obtain the ground contact determination incremental threshold Td: Td = I_touch - I_empty The difference is solidified and written into the microprocessor memory, and the preset ground contact determination increment threshold Td remains a fixed calibration value during the operation of the whole machine.

9. A low-temperature interference-resistant adaptive ground contact detection system for electric outriggers, used to implement the method as described in any one of claims 1 to 8, characterized in that, include: The current detection circuit is integrated into the control unit built into the outrigger motor driver. The control unit is equipped with a microprocessor, and the output signal terminal of the current detection circuit is electrically connected to the microprocessor through an analog-to-digital converter module. The current detection circuit is used to sample the drive current of the outrigger motor driver and convert it into a digital signal that can be received and processed by the microprocessor through analog-to-digital conversion. Current acquisition, control and filtering unit: controls the current detection circuit to acquire the drive current at a preset sampling period, performs time-domain smoothing filtering on the acquired data, and outputs the real-time filtered current If; Baseline self-learning unit: During the background characteristic acquisition stage of outrigger extension, it receives the filtered current If and executes a first-order low-pass filter update algorithm to maintain and output the reference baseline Bref in real time; Baseline locking unit: Receives travel information output by encoder or counter. When the travel reaches the preset fixed boundary point, it sends a stop update command to the baseline self-learning unit and latches the current Bref as the dynamic zero-point reference value Bsolid. Difference Calculation Unit: Calculates the difference between If and Bsolid (Diff) in real time and outputs it to the decision unit; Ground contact logic determination unit: compares Diff with the ground contact determination increment threshold Td and counts using the ground contact confirmation counter Count. If Diff ≥ Td, the ground contact confirmation counter Count is incremented; if Diff < Td, the counter Count is immediately hard-cleared and the confirmation counting restarts. When the ground contact confirmation counter Count continuously increments to reach the preset continuous valid sampling point threshold Tconfirm, the leg is determined to be in contact with the ground and a stop signal is output. The valid sampling point is the current sampling point that satisfies Diff ≥ Td.

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