A cable powered work machine protection system and method to prevent cable kinking

Abstract

The application discloses a cable power supply type engineering machinery protection system and method for preventing cable twisting, and the system comprises the following: an absolute angle monitoring module which monitors and outputs an absolute rotation angle signal between an upper vehicle and a lower vehicle of engineering machinery; the absolute angle monitoring module is connected with a hardware input end of an independent safety control module, and is provided with a non-software rewriting unit which is responsible for hardware setting and locking of a safety rotation angle threshold value; at least one hardware execution channel is directly connected between a hardware output end of the independent safety control module and a rotation power source control loop of the engineering machinery through a hard cable; the independent safety control module compares the absolute rotation angle signal with the safety rotation angle threshold value through an internal hardware circuit, and drives the hardware execution channel to act to cut off the power source when the threshold is exceeded. The cable twisting risk is completely and independently eradicated from the physical layer, and the contradiction between the cable physical safety threshold value and the traditional movement mode of the machinery is completely solved.

Description

Technical Field

[0001] This invention relates to the field of electrification and safety control technology for engineering machinery, specifically to a cable-powered engineering machinery protection system and method for preventing cable twisting. Background Technology

[0002] Traditional hydraulic excavators feature an upper section with unlimited continuous rotation capability, a design that is optimal in their self-powered mode, providing unrestricted operational flexibility. However, when adopting the new cable-powered mode, a fundamental contradiction arises between the machine's traditional characteristics and the physical constraints of the power supply medium: power cables, especially specialized anti-twist cables, have a defined maximum permissible torsional angle, and the machine's unlimited rotation capability directly leads to a significant risk of excessive cable twisting and damage.

[0003] Currently, the conventional low-voltage AC mains power supply solution for mobile devices typically connects directly to 380V / 220V low-voltage mains power. This design and application are primarily aimed at small devices or low-power scenarios. Especially for large construction machinery with power requirements typically exceeding 200kW, using 380V power would result in extremely high currents, exceeding 500A. To withstand such a large current, the required cable cross-sectional area is enormous, making the cable exceptionally heavy and rigid, extremely difficult to drag, coil, and store on-site, severely reducing equipment mobility and deployment efficiency. More importantly, tension control of the heavy cable becomes complex, exacerbating mechanical stress during the torsion process, rendering existing simple anti-twist cable measures designed for low-voltage scenarios completely ineffective.

[0004] Existing technical solutions attempting to resolve the aforementioned contradictions are mostly "external intervention" types based on outdated models. For example, Chinese patent CN120504224A discloses a control method, controller, and engineering machinery for electric engineering machinery cable reels, aiming to reduce manual labor costs caused by loose or tangled cables during operation. However, this approach suffers from the following fundamental limitations: First, the control logic is lagging. It commonly employs software feedback control based on actual displacement, resulting in slow response and an inability to prevent momentary over-limits due to misoperation. Second, the safety mechanisms are fragile. Core protection logic, such as angle monitoring and power failure detection, is typically embedded in the main control module software, creating a single point of failure risk. If the main control module malfunctions, crashes, or is interfered with, the safety functions fail. Third, there is a lack of a system-level high-voltage safety architecture. In particular, there is a lack of a systematic solution that can directly, safely, and efficiently connect to the widely available 10kV high-voltage power grid in industrial sites and provide power to large engineering machinery. Existing solutions neither solve the aforementioned physical challenges of cables under high power conditions, nor do they design an intrinsic and absolutely reliable ultimate hardware safety protection layer for high-voltage and high-risk scenarios. Summary of the Invention

[0005] This invention proposes a cable-powered engineering machinery protection system and method to prevent cable twisting. It can be directly adapted to 10kV high-voltage mains power, providing reliable and continuous power for large engineering machinery. Based on the maximum allowable torsion angle of the cable, it completely and independently eliminates the risk of cable twisting from a physical level by fixing the single-sided limit angle in hardware. It completely solves the contradiction between "cable physical safety limits" and "traditional mechanical movement modes". It can also adjust the limit angle by setting different thresholds in hardware to adapt to cables of different specifications.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a cable-powered construction machinery protection system for preventing cable twisting, comprising: an absolute angle monitoring module that monitors and outputs the absolute rotation angle signal between the loading and unloading points of the construction machinery; the absolute angle monitoring module is connected to the hardware input terminal of an independent safety control module, and is equipped with a non-software rewrite unit responsible for setting and locking the safe rotation angle threshold; at least one hardware execution channel is directly connected between the hardware output terminal of the independent safety control module and the rotation power source control circuit of the construction machinery via a rigid cable; the independent safety control module compares the absolute rotation angle signal with the safe rotation angle threshold through its internal hardware circuit, and drives the hardware execution channel to cut off the power source when the threshold is exceeded.

[0007] Preferably, the hardware execution channel includes an alarm channel and a power cut-off channel. The independent safety control module triggers the alarm channel when the absolute rotation angle reaches the warning threshold and triggers the power cut-off channel when the safe rotation angle threshold is reached. The warning threshold is smaller than the safe rotation angle threshold.

[0008] Preferably, the absolute angle monitoring module is a multi-turn absolute encoder, whose rotating shaft is mechanically coupled to the rotating shaft of the engineering machinery through a transmission mechanism.

[0009] Preferably, the transmission mechanism includes a drive component fixed to the rotary mechanism and a synchronous gear meshing with the drive component, and a speed reducer is connected between the synchronous gear and the absolute encoder.

[0010] Preferably, it includes an independent hardware protection circuit and has a force sensor installed at the stress point of the power supply cable. The signal of the force sensor is directly connected to the dedicated hardware input channel of the independent safety control module. When the detected force value exceeds a preset hardware threshold, the independent safety control module directly cuts off the main power supply to the construction machinery through an independent hardware output channel.

[0011] Preferably, the non-software rewritable unit includes a DIP switch, a hardware jumper, or a dedicated setter with a physical key.

[0012] Preferably, it also includes a main control module, which feeds forward to control the winding and unwinding speed of the cable reel based on the operation intention signal obtained from the engineering machinery, so as to coordinate the mechanical rotational motion and maintain constant tension of the cable.

[0013] Preferably, it includes a human-machine interface that displays key parameters related to power supply safety and equipment status in real time. The key parameters include the current absolute rotation angle, the remaining angle from the safe rotation angle threshold, and the real-time cable tension.

[0014] Preferably, the safe rotation angle threshold is a single-sided rotation angle limit calculated based on the maximum permissible torsion angle of the anti-torsion cable.

[0015] The present invention also adopts the following technical solution: a method for protecting cable-powered engineering machinery from cable twisting, which realizes the above-mentioned protection system for cable-powered engineering machinery from cable twisting, including the following steps: S1, obtain the maximum permissible torsion angle of the anti-torsion cable supplying power to the construction machinery; S2, Based on the maximum permissible torsion angle, determine the safe rotation angle threshold of the engineering machinery, and set the threshold in hardware in an independent safety control module; S3, continuously monitor the absolute slewing angle of the upper part, and when the absolute slewing angle reaches the safe slewing angle threshold, directly cut off the slewing power source of the construction machinery, thereby physically limiting its maximum slewing operating range to a limited angle based on the cable safety characteristics.

[0016] The beneficial effects of this invention are: it can recalculate and set different thresholds in hardware for different cable specifications to adapt to different cable specifications; it fundamentally eliminates the risk of cable twisting and achieves inherent safety in high-voltage mobile power supply; it constructs a hardware-first safety architecture to avoid software failures or network attacks that cause safety functions to fail; it establishes multiple redundant independent protection circuits to ensure that the system still has safety protection capabilities in the event of a single point of failure; it adopts a hardware setting mechanism that cannot be rewritten by software to prevent safety parameters from being maliciously tampered with or changed by misoperation; it realizes the conversion from "infinite rotation" to "limited rotation" operation mode, breaking through the technical bottleneck of traditional slip ring power supply; and it forms a collaborative monitoring system for cable spatial attitude and mechanical state to ensure the safety and reliability of the entire power supply process. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall system architecture and secure communication of the present invention.

[0018] Figure 2 This is a schematic diagram of the electrical connection of the hardware protection circuit in this invention.

[0019] Figure 3This is a block diagram of the collaborative control principle based on operational intent feedforward. Detailed Implementation

[0020] This embodiment provides a cable-powered construction machinery protection system to prevent cable twisting. Taking a large hydraulic excavator powered by cable as an example, the deployment and workflow of the cable-powered construction machinery protection system to prevent cable twisting in this invention are described in detail.

[0021] This invention constructs a three-layer architecture that coordinates the perception layer, control layer, and management layer, specifically including a perception and independent execution layer, a core control layer, and a remote interaction layer.

[0022] The sensing and independent execution layer includes a multi-turn absolute encoder that rotates synchronously with the slewing mechanism of the engineering machinery, a spoke-type tension sensor installed at the key support points of the cable, and an execution terminal directly driven by an independent safety control module through a dedicated rigid cable.

[0023] Among them, the multi-turn absolute encoder is used for absolute angle monitoring, the independent safety control module can adopt a safety PLC, and the execution terminal includes an audible and visual alarm, a rotary power contactor, and a main power relay.

[0024] The core control layer adopts a dual-core architecture, including a main control PLC responsible for intelligent collaborative control and operating condition management, and an independent safety control module that is dedicated to safety logic and physically isolated from the main control PLC.

[0025] The remote interaction layer is based on a 4G / 5G cloud platform, enabling data aggregation, remote diagnostics, authorization issuance, and transmission of lock command.

[0026] The overall system architecture and secure communication diagram are as follows: Figure 1 As shown below, in conjunction with Figure 1 The hardware installation of the system is described in detail.

[0027] To achieve continuous and dynamic power supply from the mobile power control station to the rotating construction machinery, the system is equipped with a vehicle-mounted power receiving pole assembly. This power receiving pole is an insulated robotic arm structure, with its rotating base installed at the rear of the construction machinery's off-board traveling mechanism, adjacent to the slewing bearing; its free end is equipped with a dedicated connector for connecting the power supply cable from the mobile power control station.

[0028] The core function of the power receiving pole is to serve as a dynamic power extraction interface between the fixed power supply point and the mobile loading platform, guiding and carrying the cable to form a safe and reliable power supply path.

[0029] During routine operations, the power pole is usually positioned at the center of the rear of the vehicle. When rear clearance or equipment relocation is required, the operator can issue a command via the HMI in the cab to rotate the power pole laterally to a predetermined angle to facilitate work clearance or cable insertion / removal.

[0030] To precisely control the aforementioned movements and monitor the cable status, the system is equipped with three key components: a servo cable reel, a spoke-type force sensor, and a single-turn absolute encoder.

[0031] The servo cable reel, located on the mobile power control station, is responsible for the automatic winding and unwinding of the power supply cable. Its core function is to achieve constant tension control and cable length monitoring, ensuring that the cable maintains appropriate tension during mechanical movement and avoiding slack or overload.

[0032] A spoke-type force sensor is directly mounted on the front support of the servo cable reel to monitor the cable tension in real time. This sensor signal is crucial feedback for constant tension control and is also directly connected to an independent safety controller, forming a redundant hardware safety protection loop. Specifically, it directly triggers the disconnection of the main power supply when the tension exceeds the limit.

[0033] A single-turn absolute encoder is coaxially mounted on the rotating shaft of the power receiving pole to monitor the swing angle of the power receiving pole relative to the unloading platform in real time. This angle data is transmitted to the on-board controller to display the real-time position of the power receiving pole on the HMI and to serve as an auxiliary input signal for coordinated control of the servo drum.

[0034] The hardware implementation of the security protection mechanism of this invention will be described in detail below.

[0035] The safety protection of this system relies on a fully electrically isolated triple hardware protection circuit built on an independent safety control module. These circuits are: a first circuit for angle hard limit protection, a second circuit for tension over-limit protection, and a third circuit for length over-limit protection. Figure 2 As shown.

[0036] In summary, the absolute angle monitoring module monitors and outputs the absolute rotation angle signal between the loading and unloading points of the construction machinery; the absolute angle monitoring module is connected to the hardware input terminal of an independent safety control module, and has a non-software rewrite unit responsible for setting and locking the safe rotation angle threshold; at least one hardware execution channel (Y1, Y2, Y4) is directly connected between the hardware output terminal of the independent safety control module and the rotation power source control circuit of the construction machinery via a rigid cable; the independent safety control module compares the absolute rotation angle signal with the safe rotation angle threshold through its internal hardware circuit, and drives the hardware execution channel to cut off the power source when the limit is exceeded.

[0037] The hardware execution channel includes an alarm channel and a power cut-off channel. The independent safety control module triggers the alarm channel when the absolute rotation angle reaches the warning threshold and triggers the power cut-off channel when the safe rotation angle threshold is reached. The warning threshold is smaller than the safe rotation angle threshold.

[0038] In this embodiment, the non-software rewritable unit of the independent security control module is an independent security controller, including a DIP switch, a hardware jumper, or a dedicated setter with a physical key.

[0039] Specifically, in the first loop, the absolute rotation angle signal monitored in real time by the multi-turn absolute encoder of the absolute angle monitoring module is directly connected to the independent safety controller. The controller's internal hardware circuit compares it with a fixed angle threshold. An over-limit signal directly drives the first hard-wired output point Y1 and the second hard-wired output point Y2 to execute an audible and visual alarm and cut off the rotation power.

[0040] In this embodiment, the fixed angle thresholds include a warning angle threshold set to 225° and a hard limit angle threshold set to 270°.

[0041] The system also includes an independent hardware protection circuit, equipped with a force sensor installed at the stress point of the power supply cable. The signal from the force sensor is directly connected to the dedicated hardware input channel of the independent safety control module. When the detected force value exceeds the preset hardware threshold, the independent safety control module directly cuts off the main power supply to the construction machinery through an independent hardware output channel.

[0042] Specifically, in the second circuit, the first spoke force sensor 2 and the second spoke force sensor 3, installed on the front support of the servo cable reel, directly input the real-time tension signal of the cable into the dedicated hardware analog input channel of the independent safety controller in the form of a 4-20mA analog signal. When the tension value detected by the first spoke force sensor 2 or the second spoke force sensor 3 exceeds the preset hardware threshold, the controller directly drives the main power contactor to trip through another set of independent hardware output points, cutting off the power supply to the entire machine.

[0043] In the third circuit, a length measuring unit integrated on the servo cable reel transmits the real-time cable winding and unwinding length signal to an independent safety controller. When the length reaches a preset hardware safety limit, the controller also drives the main power contactor to trip. The length measuring unit can be an absolute encoder.

[0044] The three circuits described above are physically isolated in terms of sensing objects, signal paths, and execution logic, forming a redundant safety barrier. Among them, the triggering conditions for the second and third circuits are "OR" logic; if either condition is met, the highest level of power failure protection is executed.

[0045] Therefore, this invention constructs a complete spatial attitude and mechanical monitoring system. A multi-turn absolute encoder monitors the "absolute rotation angle between the upper and lower parts of the vehicle," serving as the core basis for triggering the hardware safety protection chain; a single-turn absolute encoder monitors the "relative swing angle of the power receiving pole," working in conjunction with the servo cable reel and force sensor to achieve intelligent comprehensive management of the power cable's spatial path, tension, and length. These two systems complement each other, completely eliminating the risk of cable twisting at the physical level and ensuring the safety of high-voltage mobile power supply throughout the entire process.

[0046] A safety-type PLC is installed on the guide rail inside the waterproof electrical control box of the vehicle as an independent safety control module.

[0047] Locate the main contactor KM1 that controls the rotary hydraulic motor, disconnect the original wiring of its coil control circuit, and connect it in series with a rigid cable led out from the Y2 output point of the safety PLC.

[0048] Install a spoke-type tension sensor under the support near the cable reel outlet, and lead its signal line directly to the dedicated analog input module of the safety PLC.

[0049] The mobile power control station is the high-voltage access and power management hub of the system, and its internal electrical layout is centered on 10kV high-voltage safe access and transformation. After the 10kV mains power is introduced through high-voltage cables, it is first stepped down by a transformer to the working voltage required by the engineering machinery equipment.

[0050] The stepped-down power supply is divided into two main branches: the first branch supplies power to the drive motor of the servo cable reel and auxiliary equipment within the station; the second branch, through a power distribution circuit, provides power to the power cables output to the construction machinery. This power distribution circuit consists of circuit breakers, contactors, and other protective devices in the main control cabinet to ensure electrical safety on the output side.

[0051] The main control PLC, located inside the cabinet, does not directly manage high-voltage power distribution. Instead, it acts as the "control brain" of the station, primarily responsible for two core functions: coordinated control of the cable reel and remote communication hub. Based on feedforward commands from the onboard unit and local feedback, it precisely controls the winding and unwinding of the servo cable reel, achieving constant cable tension and length management. It maintains communication with the cloud platform via a 4G / 5G module, completing status reporting, command reception, and authorization management.

[0052] Thus, the mobile power control station integrates high-voltage transformation, safe power distribution, precise cable laying and winding, and remote interaction, forming a complete solution for ground-based fixed power supply.

[0053] The authorization management, fault diagnosis, and anti-twisting principles of the system are described below, along with its workflow and logical relationships.

[0054] After the equipment is powered on, the main control PLC begins to decrement the remaining authorized time and displays it on the HMI; when the remaining time is lower than the warning threshold, such as 24 hours, a prominent prompt will pop up on the HMI.

[0055] If the authorization expires or a lock command is received from the cloud, the main control PLC will trigger a safety signal. This signal is connected to the independent safety controller via a hardwire, which ultimately drives the main power contactor to trip, thus achieving remote safety lock.

[0056] The system's fault diagnosis system defines structured fault codes (such as F4XX for safety faults), which are recorded in real time by the corresponding controller and uploaded to the cloud via 4G / 5G modules.

[0057] This invention, through the independent hardware safety protection circuit, fundamentally transforms the slewing operation mode of engineering machinery from the traditional "unlimited slewing" to "limited slewing based on cable safety characteristics," thereby permanently eliminating the risk of cable twisting.

[0058] The steps for setting the safe mode parameters are explained in detail below.

[0059] After reviewing the equipment file, we confirmed the model of the anti-twist cable used in this project and its maximum permissible torsion angle A=540°.

[0060] On the hardware configuration module of the safety PLC (such as a DIP switch), set the single-sided hard limit angle threshold B=270°. This setting ensures that when the machine rotates no more than 270° in any direction, the total cable torsion angle will be less than the safety limit of 540°.

[0061] It should be noted that this section uses a maximum permissible torsion angle of 540° and a corresponding unilateral limit of 270° as an example to describe specific embodiments of the present invention, aiming to enable those skilled in the art to clearly understand and reproduce the present invention. This is not intended to limit the scope of protection of the present invention in any way.

[0062] In practical applications, the specific values ​​of the 'maximum permissible torsion angle' and the 'safe rotation angle threshold' calculated and set accordingly should be determined based on the actual technical parameters of the selected power supply cable. This invention protects the method and its implementation system for 'determining and hardware-locking the mechanical safe rotation range based on the cable's safety characteristics'.

[0063] Use the manufacturer's dedicated configuration tool or jumper to lock this parameter and install an anti-tamper casing.

[0064] The system also includes a main control module, which can feedforward control the winding and unwinding speed of the cable reel based on the operation intention signals obtained from the construction machinery, so as to coordinate the mechanical rotation and maintain constant tension of the cable.

[0065] The schematic diagram of the collaborative control principle of feedforward control based on operational intent is as follows: Figure 3 As shown, the main control system acquires pilot pressure or handle signals in real time through the high-speed CAN bus, converts them into speed feedforward commands for the cable reel, and sends them to the mobile power control station via wireless communication, achieving millisecond-level coordination of "the cable is adjusted before the vehicle moves".

[0066] The following is a detailed explanation of the work and protection process, including the following steps.

[0067] The operator is working normally, and the HMI interface clearly displays the current rotation angle and the remaining angle from the 270° limit.

[0068] When the vehicle rotates to the warning angle (e.g., 260°), the safety PLC drives the audible and visual alarm in the cab via the Y1 output to issue an urgent warning.

[0069] If the operator does not stop, when the machine rotates to the hard limit angle (270°), the Y2 output of the safety PLC will immediately disconnect, the hard-wired circuit will be cut off KM1, the rotary hydraulic motor will lose pressure, and the machine will be unable to continue rotating in that direction.

[0070] If the drum tension suddenly increases due to abnormal reasons (such as cable jamming) and exceeds the sensor's set threshold, the Y4 output of the safety PLC will immediately activate and directly cut off the main power contactor (KM0).

[0071] All of the above protection actions are completed independently by the hardware within 50ms, with the main control module acting only as an "observer" to record the event log.

[0072] It should be noted that this invention applies to all construction machinery that obtains power through external cables, whether it is a factory-made pure electric drive device or an electric device converted from a traditional power device.

[0073] This embodiment provides a cable-powered engineering machinery protection method to prevent cable twisting, which can realize the above-mentioned cable-powered engineering machinery protection system to prevent cable twisting.

[0074] Step S1: Obtain the maximum permissible torsion angle of the anti-torsion cable.

[0075] In this embodiment, the operator first consults the equipment file to confirm the model and technical parameters of the anti-torsion cable to be used. For example, if a certain model of high-voltage anti-torsion cable is selected, its manufacturer's technical specifications clearly state that the maximum permissible torsion angle A=540°, which is the maximum torsion angle the cable can withstand before twisting failure. This parameter is an inherent physical safety characteristic of the cable, determined by the cable's internal anti-torsion structure, such as the Kevlar fiber reinforcement layer and special stranding pitch design. It must be strictly determined according to the actual cable's manufacturer's technical documentation, rather than estimated based on experience.

[0076] It should be noted that this embodiment is described using 540° as an example to enable those skilled in the art to clearly understand and reproduce the invention. This is not a limitation on the scope of protection of the invention. In practical applications, the maximum permissible torsion angle should be determined according to the actual technical parameters of the selected power supply cable. The invention protects the core method of "determining the safe rotation angle threshold based on the cable's safety characteristics".

[0077] Step S2: Set the safe rotation angle threshold in the hardware.

[0078] Based on the maximum permissible torsion angle A obtained in step S1, the single-sided safe rotation angle threshold B is calculated and determined to be half of the maximum permissible torsion angle A, i.e., 270°. The basis for this calculation is that the slewing operation of engineering machinery is a bidirectional movement (left slewing / right slewing). By dividing the total permissible torsion angle equally to both sides, it can be ensured that the cable torsion angle does not exceed the safety limit when continuously rotating in any single direction.

[0079] Once the safe rotation angle threshold is determined, it is set in a separate safety control module via hardware.

[0080] First, open the tamper-proof shell of the independent security controller [4] and access its hardware configuration module.

[0081] Then, a single-sided hard limit angle threshold B = 270° is set using a DIP switch. The DIP switch is a physical switch array, with each bit corresponding to a specific angle value. The fixed binary code is set by mechanical toggling, and this code is directly mapped to the comparison reference value of the hardware circuit.

[0082] Alternatively, a hardware jumper can be used to short-circuit a specific pin combination on a dedicated setting interface to hard-wire and solidify the threshold parameters.

[0083] Alternatively, a dedicated setting device with a physical key can be used. After inserting the authorized key, the device enters the hardware configuration mode, where a threshold is set via a knob or button. The device automatically locks when the key is removed.

[0084] After setting, install an anti-tamper casing and seal it with lead to ensure that the threshold parameters cannot be rewritten by software commands.

[0085] This hardware setting mechanism fundamentally eliminates the risk of tampering with security parameters through communication protocols. Even if the main control system suffers a network attack or software failure, the security threshold remains fixed.

[0086] Step S3, Real-time monitoring and hardware protection actions. This step includes the following sub-steps.

[0087] Step S3.1: Continuous monitoring of absolute rotation angle.

[0088] The multi-turn absolute encoder is mechanically coupled to the slewing bearing of the construction machinery through a transmission mechanism to monitor the absolute rotation angle of the upper part relative to the lower platform in real time.

[0089] The transmission mechanism transmits the large-angle rotation of the slewing bearing (potentially exceeding 360° multiple revolutions) to the encoder via synchronous gears and a reducer, converting it into a rotational quantity that the encoder can measure, ensuring the continuity and uniqueness of angle measurement across the entire rotation range.

[0090] The absolute rotation angle signal output by the encoder is directly connected to the dedicated hardware input channel of the independent safety control module in digital form through a shielded cable, with a signal update cycle of no more than 10ms.

[0091] Step S3.2, Hardware comparison and hierarchical protection.

[0092] The internal hardware circuitry of the independent safety control module (consisting of a comparator array and fixed logic gates) executes the following comparison logic in real time.

[0093] Level 1: Early Warning.

[0094] When the absolute turning angle reaches the warning threshold of 260° (i.e., 270° - 10° safety margin), the hardware circuit drives the alarm channel Y1 to output a high-level signal; through the rigid cable, it directly drives the audible and visual alarm in the cab, emitting a rapid flashing and buzzing warning to remind the operator that the limit is about to be reached; this process is completed independently by the hardware within 50ms, without relying on the main control system software.

[0095] Second stage: power cut-off, hard limit.

[0096] If the operator does not respond to the warning and continues to operate in the same direction, when the absolute rotation angle reaches the safe rotation angle threshold of 270°, the hardware comparison circuit triggers the power cut-off channel Y2 to output a low-level signal, or disconnects the dry contact; the main contactor KM1 coil circuit controlling the rotation hydraulic motor is directly cut off through the rigid cable, the contactor trips, the rotation motor loses pressure, and the machine can no longer rotate in that direction; at the same time, the main control system records this event as a hardware safety trigger log; the operator can reduce the absolute value of the angle by operating in the opposite direction, and when the angle falls back to within 270°, the system automatically resets and restores the rotation function.

[0097] Level 3: In extreme cases, the main power supply is cut off, providing redundant protection.

[0098] Independent of angle monitoring, the spoke-type force sensor monitors cable tension in real time. When the detected tension exceeds the preset hardware threshold (such as 150% of the rated tension), the main power cut-off channel Y4 of the independent safety control module immediately activates. It directly drives the main power contactor to trip via a rigid cable, cutting off the power supply to the entire unit. This protection circuit is physically isolated from the angle protection circuit in terms of the sensing object (force rather than angle), signal path (analog input rather than digital input), and execution logic (independent output of OR gate), forming a redundant safety barrier.

[0099] Step S3.3, Human-computer interaction and status display.

[0100] The driver's cab HMI displays the following key parameters in real time: current absolute slewing angle (updated in real time, accuracy ±1°); remaining angle to the safe slewing angle threshold (e.g., "12° to the right limit"); real-time cable tension (unit: kN or N); current slewing direction indication; and remaining authorized time (for authorized management of leased equipment). Key parameter data is provided collaboratively by an independent safety control module and the main control system.

[0101] When the remaining angle is less than 10°, the HMI interface will flash red to enhance the warning effect, in conjunction with the audible and visual alarm.

[0102] Through the above steps, this embodiment achieves the following technical effects: The fundamental shift from "unlimited rotation" to "limited rotation": Traditional engineering machinery relies on slip rings or unlimited swivel joints to achieve continuous rotation. This method uses hardware-forced limiting to convert the operation mode into limited rotation based on the cable safety characteristics, fundamentally eliminating the risk of twisting.

[0103] Absolute priority of hardware security: All critical comparison, decision-making, and execution processes are completed by independent hardware circuits, with the main control system acting only as an "observer" to record logs, forming a "hardware-first, software-assisted" security architecture that meets the performance level requirements of ISO13849 for safety-related components of control systems.

[0104] Parameter anti-tampering mechanism: The security threshold is fixed by physical means such as DIP switches and jumpers, and cannot be modified by unauthorized physical access. Compared with software parameter storage (EEPROM, Flash, etc.), it has higher anti-tampering security.

[0105] Multiple redundancy and fail-safe features: Three independent inputs for angle monitoring, tension monitoring, and length monitoring; and three independent outputs for alarm, rotation cut-off, and main power cut-off. No single point of failure will cause the loss of safety functions, and the system will default to a safe state.

[0106] It should be noted that this embodiment uses a maximum permissible torsion angle of 540° and a corresponding 270° unilateral limit as an example to describe the specific implementation of the present invention. In actual engineering applications, the specific values ​​should be determined according to the actual technical parameters of the selected anti-torsion cable. The present invention protects the method and its implementation system of "determining and hardware-locking the mechanical safety rotation range based on the cable safety characteristics", rather than specific numerical limitations.

[0107] This invention abandons the old approach of patching things up and instead pioneers a new operating paradigm adapted to cable power supply, namely, a limited-rotation safe operating method based on cable characteristics.

[0108] Based on the technical specifications of the anti-twist cable selected for specific engineering machinery, its core safety parameter, the maximum permissible torsion angle A, is determined. Based on parameter A, a hardware safety angle threshold B for unilateral mechanical rotation is calculated and converted. This threshold B is set and locked through a physical module on an independent safety control unit, preventing any possibility of remote tampering via software or network. This invention sets hardware rotation limits based on the cable's physical safety parameters; the specific values ​​of these safety parameters depend on the actual cable specifications selected.

[0109] During mechanical operation, the absolute rotation angle is continuously monitored by an independent hardware circuit. Once the monitored value reaches the threshold B, the independent safety control unit, without any software logic judgment, directly drives the hard-wired circuit to cut off the mechanical rotation power source through its internal hardware comparison circuit and physical output contacts.

[0110] Through the aforementioned hardware-level enforcement measures, the maximum actual operating slewing range of the engineering machinery is permanently and physically limited to the sector area defined by threshold B, thereby completing a fundamental transformation from an "unlimited slewing" to a "cable-safe limited slewing" working mode.

[0111] To reliably implement the above method, this invention designs a dedicated "sensing-decision-execution" hardware structure.

[0112] It adopts a multi-turn absolute encoder with battery retention. Its rotating shaft rotates synchronously with the slewing mechanism of the engineering machinery through a transmission mechanism, ensuring that the monitored angle is an absolutely true angle and providing an absolute position signal that is not distorted when power is off.

[0113] The encoder signal is directly transmitted to the independent safety control unit via a shielded cable. This unit uses pure hardware circuitry, including comparators and logic gates, to construct the judgment logic. When an over-limit trigger occurs, its physical output relay directly actuates, controlling the alarm, cutting off the rotation power, and cutting off the main power supply respectively through independent rigid cable bundles. The entire chain is electrically and logically isolated from the main control system.

[0114] In addition to the main protection circuit for "angle over-limit", a completely independent protection circuit based on different physical principles is added to form a redundant safety barrier.

[0115] The first circuit implements the aforementioned angle hard limit, while the second circuit integrates a high-precision spoke-type sensor at the force support point of the cable reel to monitor cable tension in real time. Its analog signal is directly connected to another dedicated hardware analog input channel of the independent safety control unit. When the tension exceeds a preset hardware threshold, this unit directly drives the main power contactor to trip through another set of independent hardware output points. The two circuits are physically isolated in terms of the sensing object, signal path, and execution object.

[0116] The main control system acquires pilot pressure or handle signals in real time via a high-speed CAN bus, converts them into speed feedforward commands for the cable reel, and sends them to the mobile power control station via wireless communication, achieving millisecond-level coordination of "the cable adjusts before the vehicle moves" and realizing feedforward control of operation intentions.

[0117] The HMI in the cab displays key safety and status parameters in real time, such as the current absolute turning angle, the remaining angle from the hardware limit, the real-time cable tension, key parameters of the hydraulic system, the cumulative working hours of the equipment, and the authorized status, thereby enhancing the operator's situational awareness and enabling panoramic human-machine interaction.

[0118] The remote intelligent operation and maintenance system defines structured fault codes to achieve automatic fault classification, reporting, and cloud-based diagnosis. It provides non-blocking early warnings before authorization expiration, as well as secure locking and unlocking processes based on cloud commands.

Claims

1. A cable-powered engineering machinery protection system to prevent cable twisting, characterized in that, include: An absolute angle monitoring module monitors and outputs the absolute rotation angle signal between the loading and unloading points of the construction machinery. The absolute angle monitoring module is connected to the hardware input terminal of an independent safety control module and has a non-software-rewritable unit responsible for setting and locking the safe rotation angle threshold. At least one hardware execution channel is directly connected via a rigid cable between the hardware output terminal of the independent safety control module and the rotation power source control circuit of the construction machinery. The independent safety control module compares the absolute rotation angle signal with the safe rotation angle threshold through its internal hardware circuitry, and drives the hardware execution channel to cut off the power source when the threshold is exceeded.

2. The cable-powered engineering machinery protection system for preventing cable twisting according to claim 1, characterized in that, The hardware execution channel includes an alarm channel and a power cut-off channel. The independent safety control module triggers the alarm channel when the absolute rotation angle reaches the warning threshold and triggers the power cut-off channel when the safe rotation angle threshold is reached. The warning threshold is smaller than the safe rotation angle threshold.

3. A cable-powered engineering machinery protection system for preventing cable twisting according to claim 1 or 2, characterized in that, The absolute angle monitoring module is a multi-turn absolute encoder, whose rotating shaft is mechanically coupled to the rotating shaft of the engineering machinery through a transmission mechanism.

4. A cable-powered engineering machinery protection system for preventing cable twisting according to claim 3, characterized in that, The transmission mechanism includes a drive component fixed to the rotary mechanism and a synchronous gear meshing with the drive component. A speed reducer is connected between the synchronous gear and the absolute encoder.

5. A cable-powered engineering machinery protection system for preventing cable twisting according to claim 1, characterized in that, It includes an independent hardware protection circuit and a force sensor installed at the stress point of the power supply cable. The signal from the force sensor is directly connected to the dedicated hardware input channel of the independent safety control module. When the detected force value exceeds a preset hardware threshold, the independent safety control module directly cuts off the main power supply to the construction machinery through an independent hardware output channel.

6. A cable-powered engineering machinery protection system for preventing cable twisting according to claim 1, characterized in that, Non-software reprogrammable units include DIP switches, hardware jumpers, or dedicated setters with physical keys.

7. A cable-powered engineering machinery protection system for preventing cable twisting according to claim 1, characterized in that, It also includes a main control system, which feeds forward to control the winding and unwinding speed of the cable reel based on the operation intention signal obtained from the engineering machinery, so as to coordinate the mechanical rotation and maintain constant tension of the cable.

8. A cable-powered engineering machinery protection system for preventing cable twisting according to claim 1, characterized in that, It includes a human-machine interface that displays key parameters related to power supply safety and equipment status in real time. These key parameters include the current absolute rotation angle, the remaining angle from the safe rotation angle threshold, and the real-time cable tension.

9. A cable-powered engineering machinery protection system for preventing cable twisting according to claim 1, characterized in that, The safe rotation angle threshold is a single-sided rotation angle limit calculated based on the maximum permissible torsion angle of the anti-torsion cable.

10. A method for protecting cable-powered engineering machinery from cable twisting, characterized in that, Implementing the cable-powered engineering machinery protection system for preventing cable twisting as described in any one of claims 1-9 includes the following steps: S1, obtain the maximum permissible torsion angle of the anti-torsion cable supplying power to the construction machinery; S2, Based on the maximum permissible torsion angle, determine the safe rotation angle threshold of the engineering machinery, and set the threshold in hardware in an independent safety control module; S3, continuously monitor the absolute rotation angle of the upper part, and when the absolute rotation angle reaches the safe rotation angle threshold, directly cut off the rotation power source of the construction machinery.

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