A method and system for controlling heavy equipment in a confined space

Abstract

The present application relates to heavy equipment handling control technical field, disclose a kind of heavy equipment control method and system for restricted space, comprising: electric differential traction mainframe is placed below heavy equipment with two obstacle tank trolley in three-point support topology layout;Obtain initial normal static load data to execute bearing moment check, check through then release the locking of drive motor;Dynamic normal load data is received in the process, and the output torque of drive motor is executed cut-off limit operation based on this data;Drive heavy equipment to reach predetermined position, then lift heavy equipment by hydraulic claw jack, remove the traction mainframe and tank trolley at bottom, control jack slowly retract to realize landing position.The present application can avoid the drive wheel of equipment start and the process of running to idle and slip and dynamic out of control, and realize high-precision attitude alignment and non-impact smooth and safe landing position in narrow space.

Description

Technical Field

[0001] This invention relates to the field of heavy equipment handling control technology, specifically to a method and system for controlling heavy equipment in confined spaces. Background Technology

[0002] When installing and moving heavy equipment in confined spaces such as underground substations and factory passageways, the height and width of the working environment are strictly limited, making it impossible for conventional large lifting machinery or heavy forklifts to directly enter the site. Currently, the more common practice is to use multiple sets of non-powered load-bearing trolleys (such as tank trolleys) to support the bottom of the equipment, and then rely on external winches, small tractors, or manual pushing and pulling to achieve horizontal displacement of the equipment.

[0003] When compact traction equipment provides driving force directly to the bottom of heavy equipment, the normal pressure between the drive wheels and the ground in confined industrial spaces often fluctuates dynamically due to varying degrees of unevenness or localized settlement. Most existing traction control systems employ a fixed torque output strategy, failing to detect real-time changes in the normal load on the vehicle's underlying structure. In such cases, if the drive wheels pass through a small depression or the localized normal pressure decreases due to a shift in the center of gravity, the maximum static friction provided by the ground will be lower than the torque output by the motor, directly causing the drive wheels to slip. This not only leads to a momentary loss of traction power but also easily causes the entire handling system to lose control and deviate from its intended path.

[0004] Furthermore, due to the extremely small effective safety margin on both sides of the confined space, trajectory correction of heavy equipment during long-distance movement is particularly difficult. When existing equipment veers off course, it often requires interruption of movement, relying on manual pry bars to readjust the travel angles of the various trolleys at the bottom. This is not only labor-intensive but also makes it difficult to achieve a consistent curved trajectory. When the equipment finally reaches the installation position, it typically requires the use of independent hydraulic lifting tools to lift the heavy components and remove the supporting trolleys at the bottom. Due to the lack of precise closed-loop control over the unloading descent velocity, traditional placement operations are prone to stalling and sinking the moment the heavy equipment contacts the foundation, triggering severe mechanical impact. This not only poses a risk of damage to the internal structure of high-precision heavy equipment but also fails to meet the millimeter-level precision required for the installation of large equipment. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a control method and system for heavy equipment in confined spaces. It solves the problems of existing heavy equipment operating in confined spaces, such as the inability to adapt to changes in the load on the ground floor in real time, which easily leads to slippage of the drive wheels and loss of attitude, difficulty in correcting the trajectory, and the lack of control over the sinking speed during the final placement stage, which easily causes mechanical impact and affects the installation accuracy.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The first aspect of this invention provides a method for controlling heavy equipment in confined spaces, comprising the following steps:

[0008] The electric differential traction host and two obstacle-crossing tank trolleys are placed on the load-bearing platform under the heavy equipment in a three-point support topology.

[0009] The initial normal static load data is obtained by the pressure sensing module on the electric differential traction host, and the bearing torque verification is performed based on the initial normal static load data. Under the condition that the verification is passed, the hardware and software locks on the drive motors inside the electric differential traction host and distributed on both sides are released.

[0010] The system receives dynamic normal load data collected by the pressure sensing module during travel, performs a cutoff and limitation calculation on the output torque of the drive motor based on the dynamic normal load data, and applies the result to the drive motor.

[0011] After the electric differential traction host and the heavy equipment are driven by the drive motor to reach the predetermined position, the heavy equipment is lifted by the hydraulic claw jack located at the rear end. After the electric differential traction host and the obstacle crossing tank trolley are moved out, the hydraulic claw jack is controlled to retract, so that the heavy equipment completes the placement operation.

[0012] Preferably, the step of placing the electric differential traction host and two obstacle-crossing tank trolleys in a three-point support topology on the support platform under the heavy equipment includes:

[0013] The electric differential traction host is used as a single-point support structure at the rear, and the two obstacle-crossing tank trolleys are used as a double-point support structure at the front, forming a triangular three-point support layout at the bottom of the heavy equipment.

[0014] A rigid lateral connector is installed between the two obstacle-crossing tank trolleys to lock the two obstacle-crossing tank trolleys into a synchronized motion unit.

[0015] Preferably, the initial normal static load data is obtained through the pressure sensing module on the electric differential traction unit, including:

[0016] The electrical signal output by the pressure sensing module is converted into a digital quantity to generate the original normal load data sequence;

[0017] A sliding filter window is established, the original normal load data within the sliding filter window is extracted, the arithmetic mean is calculated, and the original normal load data sequence is transformed into an effective filtered normal load data sequence.

[0018] The variance value extracted from the effective filtered normal load data sequence within a set time span is compared with the system's preset steady-state tolerance threshold to obtain the initial normal static load data.

[0019] Preferably, the bearing torque verification is performed based on the initial normal static load data, and the hardware and software lock on the drive motor is released if the verification passes, including:

[0020] The initial normal static load data is logically compared with the theoretical safe bearing limit value;

[0021] Under the condition that the initial normal static load data is not less than the theoretical safe bearing limit value and a Boolean result is generated as true, a high-level signal is output to the enable control pin of the motor drive module to connect the main power supply circuit of the drive motor, and a status ready command message is sent to the wireless remote control terminal through the wireless communication module.

[0022] If a Boolean result is generated that is determined to be false, the sustaining voltage is cut off to the electromagnetic brake located on the output shaft of the drive motor, thereby locking the motor shaft.

[0023] Preferably, the dynamic normal load data of the pressure sensing module during the movement is received, and the output torque of the drive motor is truncated and limited based on the dynamic normal load data to obtain the result, including:

[0024] The dynamic normal load data is obtained by analog-to-digital conversion using a fixed sampling period;

[0025] Receive the entered floor type code, and call the friction coefficient lookup table to extract the equivalent friction coefficient that matches the floor material;

[0026] Read the actual operating radius of the drive wheel of the electric differential traction host;

[0027] A physical benchmark model for limiting torque is established by combining the dynamic normal load data, the equivalent friction coefficient and the actual operating radius, and the theoretical maximum allowable output torque is calculated based on the physical benchmark model as the basis for the calculation.

[0028] Preferably, the method involves performing a truncation and limitation calculation on the output torque of the drive motor based on the dynamic normal load data, and then applying the result to the drive motor, including:

[0029] Calculate the desired command torque;

[0030] The commanded torque and the theoretical maximum allowable output torque calculated based on the dynamic normal load data are imported into the comparison register for logical branch judgment, and the actual target output torque of the drive motor is calculated as the result.

[0031] Under the condition that the commanded torque is less than or equal to the theoretical maximum allowable output torque, the commanded torque is input into the motor drive control loop;

[0032] When the commanded torque is greater than the theoretical maximum allowable output torque, the commanded torque is truncated, and the theoretical maximum allowable output torque is used as the actual target output torque and input into the motor drive control loop.

[0033] Preferably, driving the electric differential traction host and the heavy equipment to a predetermined position based on the drive motor includes:

[0034] Receive steering correction commands and parse the target yaw rate command and the basic longitudinal travel speed command;

[0035] Extract the wheelbase span between the left and right drive wheels of the electric differential traction host;

[0036] Based on the dual-wheel differential kinematic model, and combined with the wheel track span, the basic longitudinal travel speed command and the target yaw rate command are calculated in the forward direction to obtain the target linear velocity of the left drive motor and the target linear velocity of the right drive motor.

[0037] Preferably, before removing the electric differential traction host and the obstacle-crossing tank vehicle, the method further includes:

[0038] Send speed signals with equal amplitude and opposite direction to the drive motors on the left and right sides of the electric differential traction host;

[0039] When the longitudinal axis of the electric differential traction host forms a 90° perpendicular angle with the longitudinal axis of the heavy equipment, the output speed signal stops;

[0040] The rotational torque and the equivalent rotational resistance torque are established and compared. Under the condition that the rotational torque is greater than the equivalent rotational resistance torque, the rear end of the heavy equipment begins to perform planar tail-swing rotational motion with the virtual rotation center as the center.

[0041] Preferably, after removing the electric differential traction host and the obstacle-crossing tank trolley, the hydraulic claw jack is controlled to retract, allowing the heavy equipment to complete the placement operation, including:

[0042] Control the electric differential traction host to drive out from under the heavy equipment;

[0043] A support pad is laid in the area directly below the electric differential traction unit after it has been removed.

[0044] Fine-tuning the drain valve on the manual lifting pump station connected to the hydraulic claw jack changes the flow area of ​​the drain valve port, dynamically controlling the return oil flow rate to limit the instantaneous descent speed of the internal cylinder of the hydraulic claw jack.

[0045] The high-pressure hydraulic oil in the internal cylinder of the hydraulic claw jack is controlled to flow slowly back to the oil storage tank of the manual lifting pump station through the throttling channel, so that the rear of the heavy equipment sinks smoothly and the bottom of the rear of the heavy equipment is completely supported on the support pad.

[0046] A second aspect of the present invention provides a control system for heavy equipment in confined spaces, comprising:

[0047] Electric differential traction host, two obstacle-crossing tank trolleys, pressure sensing module, central processing unit, load torque distribution module, drive motor and hydraulic claw jack;

[0048] The electric differential traction host and the two obstacle-crossing tank trolleys are placed under the heavy equipment in a three-point support topology to support the heavy equipment.

[0049] The pressure sensing module is communicatively connected to the central processing unit and is used to acquire initial normal static load data;

[0050] The central processing unit performs a load-bearing torque verification based on the initial normal static load data, and releases the hardware and software lock on the drive motor if the verification passes.

[0051] The load torque distribution module is communicatively connected to the central processing unit and is used to receive dynamic normal load data from the pressure sensing module during the travel process, perform a cutoff and limitation calculation on the output torque of the drive motor based on the dynamic normal load data to obtain the result, and apply the result to the drive motor through the central processing unit.

[0052] Based on the result, the drive motor drives the electric differential traction host and the heavy equipment to the predetermined position;

[0053] The hydraulic claw jack located at the rear end is used to lift the heavy equipment and retracts in a controlled manner after the electric differential traction host and the obstacle-crossing tank trolley are removed, so that the heavy equipment can be placed in its position.

[0054] This invention provides a method and system for controlling heavy-duty equipment in confined spaces. It offers the following advantages:

[0055] 1. This invention places the electric differential traction host and two obstacle-crossing tank trolleys in a three-point support topology under the heavy equipment. Based on the initial normal static load data obtained by the pressure sensing module, a load-bearing torque verification is performed. Only after the verification is passed is the drive motor unlocked. This design ensures the stability of the heavy equipment's supporting foundation in terms of physical structure. Simultaneously, the static verification before start-up ensures that the drive wheels of the traction host are distributed with sufficient gravity load to generate sufficient ground adhesion, preventing drive wheel slippage or thrust failure due to insufficient load distribution during the start-up phase in confined spaces.

[0056] 2. This invention acquires dynamic normal load data in real time during the movement of heavy equipment and performs cutoff and limitation calculations on the output torque of the drive motor based on this data. Due to the differences in ground flatness within the confined space, this mechanism can reflect the transient fluctuations of the downward pressure on the drive wheels in real time. Through bottom-level cutoff control, the actual output torque of the motor is strictly constrained within the theoretical boundary range determined by the maximum allowable static friction force of the current ground, avoiding dynamic loss of control when the equipment crosses uneven ground or transition layers, and ensuring smooth movement during the handling process.

[0057] 3. This invention employs a dual-wheel differential kinematic model to steer and correct heavy equipment. After reaching the predetermined position, hydraulic claw jacks are used to manage the weight of the heavy equipment. After moving out of the bottom traction vehicle, the descent speed of the hydraulic cylinders is limited by adjusting the return oil flow rate. This combined mechanism not only enables long, heavy equipment to achieve high-precision trajectory deflection and attitude alignment in narrow, confined channels, but also eliminates the mechanical impact force of the heavy equipment during the final placement stage through micro-motion settlement control, ensuring the safety and positioning accuracy of the installation and docking of large, heavy equipment. Attached Figure Description

[0058] Figure 1 This is a flowchart of the method of the present invention;

[0059] Figure 2 This is a system architecture diagram of the present invention;

[0060] Figure 3 This is a flowchart of the travel route smoothing and boundary transition processing mechanism of the present invention;

[0061] Figure 4 This is a flowchart illustrating the three-point support topology layout rule based on the center of gravity of the present invention.

[0062] Figure 5 This is a flowchart of the initial normal static load data acquisition and filtering procedure of the present invention;

[0063] Figure 6 This is the load-bearing torque verification equation and hardware unlocking / self-locking logic flowchart of the present invention;

[0064] Figure 7 The flowchart for the dynamic normal load monitoring and ground tribological model establishment of this invention is shown below;

[0065] Figure 8 This is a flowchart illustrating the real-time dynamic calculation process for the theoretical maximum permissible output torque of this invention.

[0066] Figure 9 This is a flowchart of the torque limiting and anti-runaway cutoff control law execution mechanism of the present invention;

[0067] Figure 10 This is a comparison chart of the transient slip rates of the drive wheels when crossing ground height differences according to the present invention;

[0068] Figure 11 This is a comparison diagram of the lateral error of the S-shaped narrow passage travel trajectory of the present invention;

[0069] Figure 12 A comparison diagram of the Z-axis mechanical impact force at the moment the bottom surface of heavy equipment touches the ground. Detailed Implementation

[0070] 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, and 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.

[0071] See Figure 1 and Figure 2 This invention provides a control system for heavy equipment in confined spaces, the control system comprising:

[0072] Electric differential traction unit, obstacle-crossing tank trolley, hydraulic lifting assembly, wireless remote control terminal and magnetic safety pad.

[0073] There are two obstacle-crossing tank vehicles. The two obstacle-crossing tank vehicles are connected in series by a rigid connecting rod.

[0074] The hydraulic jacking assembly includes a manual lifting pump station and hydraulic claw jacks. The manual lifting pump station and the hydraulic claw jacks are connected via high-pressure oil pipes. Multiple hydraulic claw jacks are installed and distributed around the base beam of the heavy equipment.

[0075] The electric differential traction unit is equipped with a central processing unit. The central processing unit has communication connections with a pressure sensing module, a load torque distribution module, a wireless communication module, and a drive motor.

[0076] The pressure sensing module is located inside the turntable bearing surface of the electric differential traction unit. The pressure sensing module is used to collect data on the normal load borne by the electric differential traction unit and send this normal load data to the central processing unit.

[0077] The wireless communication module establishes a signal connection with the wireless remote control terminal. The wireless communication module receives control commands from the wireless remote control terminal and transmits these commands to the central processing unit.

[0078] The load torque distribution module works in conjunction with the central processing unit (CPU). The CPU combines control commands and normal load data, performs calculations through the load torque distribution module, and then outputs drive signals to the drive motor to control the motion state of the electric differential traction unit.

[0079] See Figure 2 This invention provides a method for controlling heavy-duty equipment in confined spaces, which is based on the aforementioned heavy-duty equipment control system. The method includes the following steps:

[0080] The movement route within the confined space was leveled, ground obstacles were removed, and a transition layer was laid at the joint steps. A load-bearing platform matching the indoor floor level was constructed at the entrance of heavy equipment.

[0081] The electric differential traction unit and two obstacle-crossing tank trolleys are arranged in a three-point support topology on the support platform. The heavy equipment is hoisted and placed above the electric differential traction unit and the obstacle-crossing tank trolleys. Magnetic safety pads are attached to the outer perimeter of the bottom beam of the heavy equipment.

[0082] The central processing unit (CPU) acquires initial normal static load data through the pressure sensing module. Based on this initial normal static load data, the CPU performs a load-bearing torque verification. If the verification passes, the CPU releases the hardware and software locks on the drive motor.

[0083] The operator uses a wireless remote control terminal to control the electric differential traction unit to move into the confined space. During movement, the load torque distribution module acquires dynamic normal load data from the pressure sensor module in real time. Based on the dynamic normal load data, the load torque distribution module performs a cutoff limit calculation on the output torque of the drive motor and applies the result to the drive motor through the central processing unit.

[0084] Upon reaching the designated position, the electric differential traction unit is controlled via a wireless remote control terminal to adjust the heading. The electric differential traction unit applies thrust torque, causing the heavy equipment to rotate vertically around the midpoint of the line connecting the two obstacle-crossing tank trolleys in front for alignment.

[0085] Hydraulic claw jacks are symmetrically arranged on both sides of the bottom beam of the heavy equipment. The operator injects hydraulic oil into the hydraulic claw jacks through the high-pressure pump station, driving the hydraulic claw jacks to lift the heavy equipment, so that the bottom of the heavy equipment is separated from the electric differential traction host and the obstacle-crossing tank trolley.

[0086] Remove the electric differential traction unit and the obstacle-crossing tank trolley. Place a pad under the bottom beam of the heavy equipment. The operator raises the high-pressure pump station to release pressure and controls the hydraulic claw jacks to retract, allowing the heavy equipment to lower onto the pad, completing the placement operation.

[0087] See Figure 3 For the ground conditions within the confined space, a preliminary environmental adaptive processing operation is performed. The mechanism for smoothing the travel route and handling boundary transitions includes the following steps:

[0088] S201. Construct an access support platform at the entry point for the heavy equipment. When constructing this platform, use a combination of sleepers, steel beams, and steel plates to build the platform base and bearing surface. Ensure the upper surface height of the access support platform is flush with the indoor floor level of the confined space. Set the width parameter of the access support platform so that it falls within the range of 1.5 to 2.0 times the width of the heavy equipment body.

[0089] S202, Obtain the road surface height difference and obstacle attribute types along the travel route. Obstacle attribute types include rigid protrusions, metal embedded joints, and downward-sloping potholes.

[0090] S203, Perform leveling of rigid protrusions. When rigid protrusions such as conduits or reinforcing bars protruding from the ground are detected on the travel route, a cutting operation is performed on the rigid protrusion to make its top flush with the surrounding ground, eliminating rigid protrusions that obstruct the travel surface.

[0091] S204, Perform boundary slope transition treatment for metal embedded joints or steps. Set a height difference threshold, which is 1cm in this system. Compare the road surface height difference with the height difference threshold. If the road surface height difference is greater than or equal to the height difference threshold, lay a boundary transition treatment component at the corresponding height difference location. The specific implementation feature of the boundary transition treatment component here includes a flexible rubber pad. The flexible rubber pad is laid on the edge of the embedded joint or step to construct a smooth slope transition structure, preventing structural jamming or wheel damage to the electric differential traction unit or obstacle-crossing tank when passing through this location.

[0092] S205, Perform rigid bridging coverage for downwardly recessed potholes. When potholes exist on the travel route, rigid bridging components are laid over them. The specific implementation features of the rigid bridging component include 7075 aerospace-grade aluminum alloy plates. The 7075 aerospace-grade aluminum alloy plates are laid flat over the pothole, with both ends supported on solid ground at the edges of the pothole, forming a continuous rigid travel surface.

[0093] For the selection and verification of the thickness parameters and yield strength of the aforementioned rigid cross-connectors, those skilled in the art can perform mechanical calculations based on the geometric span of the pothole and the concentrated load applied by the heavy equipment in the wheel crushing area. The verification of its bending section modulus and material selection are well-known technologies in this field and will not be elaborated here.

[0094] See Figure 4 Based on the travel route conditions within a confined space, the heavy equipment control system controls the load-bearing device to perform spatial asymmetric load-bearing layout control at the bottom of the heavy equipment. This center-of-gravity-based triangular three-point support topology layout rule includes the following steps:

[0095] S301. Establish a triangular three-point support topology. Obtain the longitudinal coordinates of the center of gravity and the boundary parameters of the bottom beam of the heavy equipment. Using the electric differential traction host as the single-point support structure at the rear and two obstacle-crossing tank trolleys as the double-point support structure at the front, a triangular three-point support layout is formed at the bottom of the heavy equipment.

[0096] S302, a dual-point support structure for positioning and locking the front end. Based on the width spacing of the bottom side beams of the heavy equipment, two obstacle-crossing tank trolleys with load-bearing steering trays are pushed parallel to each other directly below the front side beam of the heavy equipment. The positions of the obstacle-crossing tank trolleys are adjusted so that the axes of the middle load-bearing wheel sets of the obstacle-crossing tank trolleys intersect perpendicularly with the longitudinal centerline of the side beam. A rigid transverse connector is installed between the two obstacle-crossing tank trolleys to lock them into a synchronous movement unit. The specific feature of the rigid transverse connector mentioned here includes a seamless steel pipe.

[0097] Seamless steel pipes are laterally inserted into the reserved holes of the two obstacle-crossing tank trolleys through hinged pins or universal joints to prevent relative displacement or outward expansion of the obstacle-crossing tank trolleys on both sides during transportation, while allowing the obstacle-crossing tank trolleys to deflect at the yaw angle when subjected to lateral forces.

[0098] S303, a single-point support structure for positioning and locking the rear end. The pressure-bearing turntable of the electric differential traction unit is pushed to directly below the midpoint of the crossbeam at the rear end of the heavy equipment. The mechanical limiting component on the pressure-bearing turntable is adjusted so that it conforms to the solid boundary of the crossbeam. A specific lower feature of the mechanical limiting component mentioned here includes an adjustable limiting block. The adjustable limiting block is pushed so that its inner surface is pressed against the front and rear sides of the crossbeam of the heavy equipment, restricting the relative longitudinal sliding between the electric differential traction unit and the heavy equipment.

[0099] S304 performs a longitudinal offset check of the center of gravity based on static equilibrium. The system uses the longitudinal coordinates of the center of gravity of the heavy equipment as the reference origin and extracts the horizontal longitudinal distribution distance from the center of gravity to the center of gravity of the electric differential traction host's pressure center and the midpoint of the line connecting the two obstacle-crossing tank trolleys. Based on the principle of static moment balance, the system combines the total mass of the heavy equipment and gravitational acceleration to analyze the theoretical vertical normal load distributed at the electric differential traction host.

[0100] To ensure sufficient ground traction for the drive wheels of the electric differential traction unit, a minimum safe load percentage threshold is preset within the system. System controllers or execution terminals compare the actual load percentage with this safe load percentage threshold and adjust the longitudinal position of the electric differential traction unit or obstacle-crossing tank vehicle. This causes the center of gravity of the heavy equipment to be specifically offset towards the electric differential traction unit in its longitudinal projection, thereby increasing the downward load at the rear and meeting the anti-slip force requirements of the drive wheels.

[0101] S305, Perform spatial avoidance processing of weak stress points on the bottom beam of the heavy equipment. Obtain the structural assembly information of the bottom beam of the heavy equipment. When the bottom beam has a longitudinal joint composed of bolted joints, set a safe distance to avoid the joint point. Adjust the longitudinal coordinates of the obstacle-crossing tank trolley and the electric differential traction host so that the load-bearing support point is not directly below the longitudinal joint, and the distance of the load-bearing support point across the longitudinal joint is greater than the safe distance to avoid the joint point, to prevent the bottom beam of the heavy equipment from breaking under load.

[0102] For the specific numerical calculation of the safety distance for avoiding the splicing points and the solution of the bending moment distribution diagram of the bottom beam of heavy equipment, those skilled in the art can establish a beam element mechanical model based on the allowable stress of the bottom beam material and the shear strength of the bolt group to calculate the results. The method for verifying the bending resistance of the local section is a well-known technology in this field and will not be elaborated here.

[0103] S306, Install anti-tipping safety components. After the heavy equipment is smoothly lowered onto the triangular three-point support topology, multiple anti-tipping safety components are attached around the edge of the bottom beam of the heavy equipment. Specific features of the anti-tipping safety components include magnetic safety pads. These magnetic safety pads are magnetically attached to the outer perimeter of the bottom beam. When the heavy equipment tilts abnormally laterally during transport, the bottom surface of the magnetic safety pads preferentially contacts the ground to form rigid support, preventing the entire heavy equipment from tipping over.

[0104] See Figure 5 During the phase where heavy equipment falls into contact with the load-bearing system but before the external lifting slings are completely removed, the system's underlying control architecture executes an initial normal static load data acquisition and filtering procedure. This data acquisition and filtering mechanism includes the following steps:

[0105] S401 receives a trigger signal and activates the sensing hardware. The central processing unit (CPU) receives a start-up verification command from the wireless remote control terminal. The CPU outputs an enable voltage to the pressure sensing module located inside the pressure-bearing turntable of the electric differential traction host. The specific lower-level implementation features of the pressure sensing module include column-type load cell assemblies. Multiple column-type load cell assemblies are evenly distributed in a circular array within the base interlayer of the pressure-bearing turntable for multi-point synchronous sensing of the vertical downward pressure applied by the heavy equipment. The analog voltage signals from the multiple column-type load cell assemblies are aggregated through a summing junction box and then input to the analog-to-digital converter circuit.

[0106] S402 performs high-frequency acquisition of discrete raw data sequences. The analog-to-digital converter continuously reads the electrical signal output by the pressure sensing module at a set sampling frequency and converts it into a digital quantity to generate a discrete raw normal load data sequence. Due to the release process of the residual tension in the crane wire rope and the slight sway of the center of gravity of the heavy equipment, high-frequency mechanical vibration noise and transient jump interference are inevitably superimposed on this raw normal load data sequence.

[0107] S403 is a digital filtering process based on a sliding window model. The CPU establishes a fixed-length first-in-first-out (FIFO) data queue in memory as a sliding filter window, and sets the specific number of sampling points included in this window. The CPU slides this window point by point in time steps, extracting the original normal load data at each discrete moment within the window, and calculates the arithmetic mean of these data. This arithmetic averaging effectively reduces the impact of random pulse interference and periodic mechanical oscillations on the true load value. By continuously executing the above sliding filter mechanism, the CPU smooths the original normal load data sequence with high-frequency spikes, transforming it into a smoothly transitioning, effectively filtered normal load data curve.

[0108] S404 performs steady-state determination and initial normal static load truth extraction. The central processing unit evaluates the data dispersion of the latest output of multiple consecutive effective filtered normal load data points. It extracts the range or variance of the effective filtered normal load data sequence within a set time span and compares it with the system's preset steady-state tolerance threshold.

[0109] For the variance calculation and range steady-state convergence determination operations of the above discrete data sequences, those skilled in the art can implement them using conventional programming logic structures based on the principles of mathematical statistics. The underlying data statistics and determination algorithms are well-known technologies in this field and will not be elaborated here.

[0110] See Figure 6 After the central processing unit (CPU) extracts stable initial normal static load data, it performs boundary calculations and response operations for the bearing moment in the underlying hardware network. The bearing moment verification equation and hardware unlocking and self-locking logic include the following steps:

[0111] S501, retrieve the system's preset mechanical reference parameters. The central processing unit reads the pre-entered total mass data of the heavy equipment from the storage unit, extracts the built-in gravitational acceleration constant, and reads the set minimum safe load percentage threshold. Under normal flat ground handling conditions, considering the ground adhesion limitation, the minimum safe load percentage threshold is set to 0.3, which is used to define the minimum gravity load percentage that the electric differential traction host must bear.

[0112] S502 executes Boolean operations for the load-bearing torque verification logic. The central processing unit (CPU) calculates the theoretical safe load floor value based on the total mass of the heavy equipment, the gravitational acceleration constant, and the set minimum safe load percentage threshold. Subsequently, the CPU inputs the collected and filtered initial normal static load data into the built-in verification model, and performs a logical comparison between the measured initial normal static load data and the theoretical safe load floor value.

[0113] If the initial normal static load data is not less than the theoretical safe bearing limit value, a Boolean result that is judged as true is generated; otherwise, a Boolean result that is judged as false is generated.

[0114] S503, executes the hardware unlocking linkage in the verified state. When the Boolean judgment result is true, it indicates that the vertical load currently allocated to the electric differential traction host for the heavy equipment meets the mechanical requirements for drive anti-slip. The central processing unit sends a hardware unlocking signal to the actuator bus. The specific lower-level implementation features of the hardware unlocking signal mentioned here include enable level toggling and ready message broadcasting.

[0115] The central processing unit (CPU) outputs a high-level signal to the enable control pin of the motor drive module, connecting the main power supply circuit of the drive motor. The CPU then sends a status-ready command message to the wireless remote control terminal via the wireless communication module. The wireless remote control terminal parses the message and illuminates the status indicator light on the control panel. The operator uses this status indicator light to release the slings of the external lifting equipment and gain control of the heavy equipment.

[0116] S504, hardware self-locking and alarm linkage in the case of execution failure. When the Boolean judgment result is false, it indicates that the load sharing at the electric differential traction host is insufficient, and direct drive is prone to wheel slippage. The central processing unit disables the enable output of the drive motor main power supply circuit. The specific lower-level action characteristics of the disabled output here include triggering electromagnetic brake locking.

[0117] The central processing unit (CPU) cuts off the sustaining voltage to the electromagnetic brake mounted on the output shaft of the drive motor. The internal spring of the electromagnetic brake resets and presses the friction plate, locking the motor shaft and preventing any translational or rotational movement. The CPU outputs drive current to the peripheral alarm components. The specific implementation features of the peripheral alarm components include a buzzer assembly and a warning light strip. The buzzer assembly emits intermittent beeps, and the warning light strip flashes red, providing feedback to the operator regarding a load ratio failure signal.

[0118] S505 is a layout correction action that responds to the hardware self-locking state. After triggering the hardware self-locking and alarm linkage, the external lifting equipment maintains the tensioned state of the heavy equipment. The operator releases the locked state of the electromagnetic brake through the mechanical release device (or operates the external lifting equipment to move the heavy equipment horizontally), and then moves the position of the pressure turntable of the electric differential traction host longitudinally along the bottom beam, shortening the horizontal projection distance from the pressure turntable to the center of gravity of the heavy equipment, thereby increasing the load distributed to the rear end.

[0119] After the position adjustment is completed, the central processing unit re-triggers the sampling and filtering mechanism of the initial normal static load data, and repeatedly executes the verification equation in step S502 until the equation conditions are met, and the system releases the hardware self-locking state.

[0120] The mechanical structure principle of the aforementioned electromagnetic brake and the switching mechanism of the insulated gate bipolar transistor inverter circuit inside the motor drive module can be consulted by those skilled in the art based on conventional motor control engineering. The underlying drive and braking response process is well-known in the field and will not be elaborated here.

[0121] See Figure 7During the traction of heavy equipment by an electric differential traction unit, the system enters a dynamic load condition. At this time, the underlying control architecture activates a real-time intervention control mechanism to prevent slippage and loss of control. The dynamic normal load monitoring and ground friction model establishment include the following steps.

[0122] S601 performs high-frequency continuous sampling of the dynamic normal load. During travel, when heavy equipment crosses the edge of rubber ramps or aviation aluminum plates, the geometric undulations of the ground and the slight elastic deformation of the bridging components cause a transient shift in the overall center of gravity of the heavy equipment. This shift in center of gravity causes a sharp fluctuation in the vertical downward pressure distributed at the turntable of the electric differential traction host. The load torque distribution module sends a synchronous sampling clock signal to the pressure sensing module. The specific lower-level implementation features of the high-frequency continuous sampling mentioned here include analog-to-digital conversion using a fixed sampling period of not less than 50Hz. The instantaneous dynamic normal load at this point in time is obtained.

[0123] S602, determine and configure the equivalent friction coefficient of the driving environment. The central processing unit (CPU) obtains the ground material attribute information of the work area through the peripheral interface. Specific details of obtaining this attribute information include receiving the floor type code entered by the operator through the human-machine interface of the wireless remote control terminal. The floor type code covers epoxy flooring, cured concrete flooring, and areas with transition rubber mats. Based on the received floor type code, the CPU retrieves the corresponding friction coefficient lookup table from its internal non-volatile memory to extract the equivalent friction coefficient matching the current ground material.

[0124] S603, Obtain System Mechanical Parameters. The load torque distribution module reads the geometric dimension parameters of the electric differential traction host drive wheel from the system configuration file and extracts the actual working radius of the drive wheel. The actual working radius is the vertical distance from the drive wheel axle center to the geometric center of ground contact.

[0125] S604 establishes the ultimate anti-skid physical model of the wheel-ground contact surface. Based on the theory of vehicle ground mechanics, the mechanical boundary condition of the drive wheel rolling purely on the ground without macroscopic slippage is such that the tangential traction force generated at the wheel-ground contact patch must not exceed the maximum static friction force determined by the current transient dynamic normal load and the equivalent friction coefficient.

[0126] The system, by combining the operating radius of the drive wheel, converts the maximum static friction force into an instantaneous theoretical limit torque acting on the drive wheel axle. Through the product relationship between dynamic normal load, equivalent friction coefficient, and operating radius, the system constructs a physical benchmark model of the limit torque for subsequent low-level control.

[0127] Based on this physical benchmark model, when the dynamic normal load drops instantaneously due to uneven ground, the system can simultaneously analyze the transient descent boundary of the drive wheel's anti-slip capability, providing data basis for the intervention of the control system.

[0128] Regarding the shear stress distribution at the tire contact patch and the calculation of the micro-slip ratio caused by the hysteresis effect of the rubber material, those skilled in the art can establish the contact area integral equation based on the standard model of vehicle ground mechanics. The tribological derivation process of the tire and hard road surface is a well-known technology in this field and will not be elaborated here.

[0129] See Figure 8 After establishing the ultimate anti-skid physical model of the wheel-ground contact surface, the control system needs to reserve anti-skid compensation space within the theoretical limit boundary. The load torque distribution module performs real-time dynamic calculation of the theoretical maximum permissible output torque. This calculation process includes the following steps.

[0130] S701, Obtain system safety compensation parameters. The load torque distribution module extracts the safety margin coefficient from the controller's storage unit. The safety margin coefficient is used to compensate for the dynamic transfer of longitudinal load caused by heavy equipment during start-up or braking, and to offset the nonlinear fluctuations in friction caused by changes in the local micro-roughness of the ground within the confined space. The specific lower-level implementation features of extracting the safety margin coefficient here include reading the preset calibration parameter block in the Flash storage area inside the central processing unit.

[0131] S702, constructing the control equation for the theoretical maximum permissible output torque. The load torque distribution module combines the equivalent friction coefficient, the transient dynamic normal load acquired at the current discrete moment of the system, the working radius of the drive wheel, and the safety margin coefficient through multiplication. The system thus establishes the following theoretical maximum permissible output torque control equation for bottom-level anti-skid intervention:

[0132] ;

[0133] in, This is the theoretical maximum permissible output torque; It is the equivalent coefficient of friction; The transient dynamic normal load acquired at the current discrete moment; The operating radius of the drive wheel; This refers to the safety margin factor. This represents the current discrete time.

[0134] In the above equation, Defined as the system in any The system sets the maximum allowable torque output of the drive motor to the drive shaft at any given time. When the drive motor's output exceeds this limit, the system determines that the drive wheel will exceed the maximum static friction adhesion limit of the ground and enter a sliding friction state.

[0135] The S703 performs real-time updates of the dynamic torque threshold. The CPU continuously solves the theoretical maximum permissible output torque control equation at the same clock cycle as the analog-to-digital converter. Through continuous calculation updates, the CPU generates a threshold in system memory that varies with the dynamic normal load. A synchronously fluctuating torque limiting boundary data stream. This torque limiting boundary data stream provides a real-time comparison benchmark for subsequent motor control law calculations.

[0136] For the underlying register call rules and timing control of the floating-point multiplication operations performed by the arithmetic logic unit inside the central processing unit, those skilled in the art can refer to the datasheet of the corresponding microcontroller to write the underlying code. The underlying arithmetic operation mechanism of the microprocessor is a well-known technology in the field and will not be described in detail here.

[0137] Referring to section 9, after calculating the theoretical maximum allowable output torque in real time, the load torque distribution module, in conjunction with external inputs, performs low-level restrictions on the output state of the drive motor. The specific execution mechanism of this torque limiting and anti-runaway cutoff control law includes the following steps.

[0138] S801: Obtain the desired torque command issued by the control terminal. The operator pushes the joystick on the wireless remote control terminal. The potentiometer inside the wireless remote control terminal converts the mechanical displacement of the joystick into an electrical signal, which is then transmitted to the wireless communication module via the radio frequency channel. The central processing unit receives and analyzes this electrical signal, and, combined with the internally stored thrust mapping curve, calculates the current discrete moment. The command torque that the operator expects to obtain is denoted as... The specific lower-level implementation characteristics of the electrical signal described here include pulse width modulation signals.

[0139] S802 constructs and runs a segmented cutoff control law model. Within the same sampling period, the load torque distribution module imports the calculated command torque and the theoretical maximum allowable output torque into a comparison register. Based on the relationship between these two values, the load torque distribution module performs logical branching decisions and calculates the actual target output torque of the drive motor. The mathematical equations corresponding to this cutoff control law model are as follows:

[0140] ;

[0141] in, The actual target output torque of the drive motor; Command torque; This is the theoretical maximum permissible output torque; This represents the current discrete time.

[0142] S803 executes normal following control under conditions where limits are not exceeded. The load torque distribution module determines the load based on the above model. This determination indicates that the static friction adhesion between the current electric differential traction unit and the ground is sufficient to provide the expected thrust. The central processing unit will proceed according to the normal process. It is input as the target variable into the motor drive control loop.

[0143] The specific lower-level implementation features of the motor drive control loop described here include a current proportional-integral-derivative closed-loop regulator. The regulator is based on... By changing the duty cycle of the power switching transistors in the inverter circuit, the stator current of the motor is driven to generate a matching electromagnetic torque, thereby achieving direct tracking of the command torque.

[0144] S804 executes the corresponding angular acceleration limiting response. Simultaneously with triggering the runaway prevention truncation intervention, the central processing unit inserts rate-of-change limiting logic into the feedforward channel of the motor drive control loop. The specific lower-level implementation features of this rate-of-change limiting logic include a slope limiter.

[0145] when When a step-down truncation occurs, the slope limiter sets a saturation upper limit on the time derivative of the drive motor speed. By controlling the angular acceleration of the motor, the mechanical impact of sudden torque changes on the gearbox transmission gears is mitigated, and longitudinal mechanical oscillations of the drive wheels near the critical slip point are suppressed.

[0146] For the above-mentioned proportional-integral coefficient tuning method for the closed-loop parameters of the internal current of the motor and the compensation setting for the conduction dead time of the power switch tube, those skilled in the art can make engineering configurations based on the motor control principle. The underlying commutation principle of its field-oriented control is a well-known technology in this field and will not be elaborated here.

[0147] Upon entering the confined space, the heavy equipment, consisting of a rear-end electric differential traction unit and a front-end obstacle-crossing tank trolley, forms a non-holonomic constrained motion system similar to a semi-trailer vehicle. Along the predetermined route, differential heading correction control is executed within the narrow passage. This process includes the following steps:

[0148] S901 receives steering correction commands and extracts control parameters. The operator operates the steering control component of the wireless remote control terminal. The central processing unit receives electrical signals transmitted by the wireless communication module and parses the target yaw rate command and the basic longitudinal travel speed command from these signals.

[0149] S902 performs differential kinematics model calculations and underlying speed distribution. The load torque distribution module extracts the wheelbase span between the left and right drive wheels of the electric differential traction unit. Based on the dual-wheel differential kinematics model and the aforementioned wheelbase span parameter, the central processing unit performs forward calculations on the basic longitudinal travel speed command and the target yaw rate command to obtain the target linear velocities of the left and right drive motors, respectively. The differential kinematics calculation equations are established as follows:

[0150] ;

[0151] ;

[0152] in, The target linear velocity of the left-side drive motor; The target linear velocity of the right-side drive motor; The basic longitudinal travel speed command; The target yaw rate command; This refers to the wheelbase span between the left and right drive wheels of the electric differential traction unit.

[0153] The central processing unit will calculate and This is converted into the corresponding rated speed signal of the motor and sent to the motor drive control loops on the left and right sides respectively. The two drive motors operate at different speeds, forcing the electric differential traction host to generate a dynamic deflection angle around its vertical axis.

[0154] S903 performs dynamic transmission of thrust vector and front-end trajectory tracking. After the mechanical orientation of the electric differential traction unit deflects, the direction of its longitudinal thrust forms an angle with the longitudinal centerline of the heavy equipment. This angle causes the output thrust of the traction unit to decompose into a lateral thrust component at the load-bearing crossbeam at the rear of the heavy equipment. The lateral thrust component applies a yaw moment to the heavy equipment, driving lateral displacement at the rear of the heavy equipment. The lateral displacement at the rear of the heavy equipment is rigidly transmitted through the bottom beam, changing the direction of the traction force on the front obstacle-crossing tank trolley. The heading angle of the front obstacle-crossing tank trolley deflects accordingly, thereby guiding the front of the heavy equipment to track the target coordinates.

[0155] S904 performs differential speed limiting protection control in narrow passages. When performing yaw correction in a confined space, if the traction main unit's yaw rate is too high, a lateral force exceeding the maximum static friction of the ground will be generated at the obstacle-crossing tank trolley, causing lateral slippage of the front wheelset. The central processing unit inserts a differential speed limiter into the forward path of the control logic. This differential speed limiter converts the target yaw rate command... The absolute value is limited to within the system's preset anti-skid angular velocity threshold. The specific features of this anti-skid angular velocity threshold include a critical angular velocity variable calculated by collecting data on the lateral friction coefficient between the wheel hub material of the obstacle-crossing tank and the ground. When the command exceeds this critical angular velocity variable, the differential limiter clamps the command value, constraining the speed difference between the left and right drive wheels, and maintaining a smooth track-changing response for the heavy equipment within the passage.

[0156] Regarding the closed-loop speed regulator configuration and encoder pulse feedback speed measurement mechanism involved in the above-mentioned independent drive of left and right wheels, those skilled in the art can build the system circuit based on conventional servo control theory. The motor speed closed-loop control method is a well-known technology in this field and will not be elaborated here.

[0157] After guiding the front-end obstacle-crossing tank trolley to the predetermined coordinates, the overall longitudinal displacement of the heavy equipment is basically completed, and the system enters the final attitude adjustment stage. The execution of the vertical rotation alignment logic around the midpoint of the front-end connection includes the following steps.

[0158] S1001, Perform orthogonal attitude adjustment of the electric differential traction unit. The operator inputs a stationary turning command into the wireless remote control terminal. The central processing unit sends equal amplitude and opposite direction speed signals to the drive motors on both sides of the electric differential traction unit. The electric differential traction unit performs a zero-radius stationary rotation below the rear end of the heavy equipment. When the longitudinal axis of the electric differential traction unit forms a 90° perpendicular angle with the longitudinal axis of the heavy equipment, the central processing unit stops outputting speed signals, locking the electric differential traction unit in this orthogonal attitude.

[0159] S1002, perform forced low-speed gear switching and parameter reset. To provide sufficient lateral push-pull torque and prevent attitude adjustment overshoot, the central processing unit (CPU) forces the motor drive control loop to switch to a low-speed gear ratio mapping gear. In this gear, the CPU limits the maximum operating speed of the drive motor while relaxing the current limiting threshold, thereby increasing the peak output torque of the drive motor at low speeds.

[0160] S1003, Establish a virtual rotation center and rotational dynamics model. The front end of the heavy equipment consists of two obstacle-crossing tank trolleys connected by a transverse rigid connector, which bear the normal reaction force from the ground. The system sets the midpoint of the geometric connection between these two obstacle-crossing tank trolleys as the virtual rotation center.

[0161] The electric differential traction unit outputs thrust along its longitudinal axis in an orthogonal posture. This thrust acts on the rear end of the heavy equipment, converting into lateral traction force. The system calculates the rotational torque generated by the lateral traction force based on the longitudinal span from the load-bearing point of the electric differential traction unit to the virtual center of rotation, and compares and analyzes this torque with the equivalent rotational resistance torque generated by the front end of the heavy equipment at the virtual center of rotation against ground friction.

[0162] When the rotational torque generated by the lateral traction force is greater than the equivalent rotational resistance torque, the system determines that the critical condition for starting the rotation has been met. The rear end of the heavy equipment overcomes the static friction resistance and begins to perform planar tail-swing rotation with the virtual rotation center as the center.

[0163] S1004 executes point-to-point rotational motion control and axis alignment. The electric differential traction unit continuously applies lateral traction force, driving the rear end of the heavy equipment to move laterally along an arc trajectory. During this process, the overall attitude angle of the heavy equipment deflects. The operator monitors the longitudinal axis of the heavy equipment through an external reference datum. When the longitudinal axis of the heavy equipment is parallel to the preset target installation datum line within the confined space, the central processing unit cuts off the output of the lateral traction force, causing the heavy equipment to stop rotating.

[0164] S1005 executes orthogonal attitude restoration and linear micro-shifting alignment. After completing axis alignment, the electric differential traction host is controlled to turn in place again, eliminating the 90° vertical angle and restoring its longitudinal axis to a state parallel to the longitudinal axis of the heavy equipment. The central processing unit receives the micro-displacement command and controls the electric differential traction host to perform small-amplitude forward and reverse drive. The electric differential traction host pushes the heavy equipment along the longitudinal axis for linear micro-adjustment until the mounting docking hole at the bottom of the heavy equipment is vertically aligned with the center of the pre-embedded part in the ground.

[0165] Regarding the differential mapping relationship between the left and right motors for the zero-radius in-place turning command and the motor phase current limiting adjustment mechanism in low-speed gear, those skilled in the art can program and modify it according to the parameter tuning rules inside the motor servo driver. The switching of its control parameter gears is a well-known technology in the field and will not be elaborated here.

[0166] After the heavy equipment is aligned, the load-bearing system enters a segmented dismantling and repositioning process. The first stage, involving the disengagement of the rear traction unit and the initial hydraulic micro-motion settling, includes the following steps.

[0167] S1101, Locate the hydraulic force-bearing point and arrange the rear hydraulic lifting assembly. Obtain the bottom gap dimensions on both sides of the rear bottom beam of the heavy equipment. Position the hydraulic lifting assemblies at corresponding positions on the left and right sides of the rear end of the heavy equipment. The specific lower-level implementation features of the hydraulic lifting assembly here include hydraulic claw jacks. Horizontally push the bottom bearing claw of the hydraulic claw jack into the gap between the sides of the bottom beam and the ground, adjusting the posture of the hydraulic claw jack to ensure full contact between the upper surface of the claw and the lower metal surface of the bottom beam of the heavy equipment.

[0168] S1102, Connect the hydraulic power source and construct a safe operating position. The specific implementation features of the hydraulic power source here include a manual lift pump station. A long, high-pressure resistant flexible oil pipe is used to fluidly connect the output interface of the manual lift pump station to the input interfaces of the hydraulic claw jacks on both sides. The manual lift pump station is placed at a safe distance outside the vertical projection outline of the heavy equipment, constructing a hydraulic power transmission channel outside the blind zone, preventing operators from operating the heavy equipment from its suspended bottom.

[0169] S1103 executes pressure holding and lifting, and load-bearing point mechanical transfer. The operator raises the pressure rod of the high-pressure pump station to pump high-pressure hydraulic oil into the bottom oil chamber of the hydraulic claw jack. The piston rod inside the hydraulic claw jack extends upward against gravity, driving the bearing claw to vertically lift the rear of the heavy equipment. The central processing unit continuously monitors the normal load feedback value of the pressure sensing module located in the pressure-bearing turntable of the electric differential traction host. When the normal load data drops to zero, it indicates that the weight of the rear of the heavy equipment has been completely transferred to the hydraulic claw jacks on both sides, and the bottom surface of the heavy equipment has disengaged from the pressure-bearing turntable of the electric differential traction host.

[0170] S1104, Remove the electric differential traction unit and lay temporary support blocks. The wireless remote control terminal issues a straight-back command to the electric differential traction unit. The electric differential traction unit disengages from its load-bearing state and autonomously moves out of the confined space beneath the heavy equipment. Support blocks are laid in the area directly beneath the electric differential traction unit after its removal. The specific lower-level implementation features of the support blocks here include a composite assembly of square timber and solid steel plates. The total height parameters of the support blocks are configured so that the elevation of its upper surface is slightly higher than the final predetermined installation height of the heavy equipment, but lower than the current height of the bottom surface of the lifted heavy equipment.

[0171] S1105, Establish a micro-motion settling flow control model and execute the first-stage positioning. The operator fine-tunes the relief valve on the manual booster pump station counterclockwise to establish a micro-motion return oil model for the hydraulic cylinder. The system acquires physical parameters such as the instantaneous flow area of ​​the relief valve orifice, the system pressure difference between the working pressure in the hydraulic cylinder and the return oil pressure in the oil tank, the fluid density of the hydraulic oil, and the flow coefficient of the relief valve orifice. Based on fluid mechanics principles and the above parameters, the instantaneous relief flow control equation of the hydraulic system is established as follows:

[0172] ;

[0173] in, This refers to the instantaneous oil discharge flow rate of the hydraulic system. The flow coefficient at the outlet of the relief valve; The instantaneous flow area at the outlet of the relief valve; This is the system pressure difference between the working pressure inside the hydraulic cylinder and the return oil pressure from the oil tank. This refers to the fluid density of the hydraulic oil.

[0174] The system combines the effective piston pressure area of ​​the internal cylinder of the hydraulic claw jack to convert the instantaneous oil discharge flow rate calculated according to the fluid control equation into the instantaneous descent speed of the rear of the heavy equipment as the hydraulic cylinder retracts. The operator can dynamically control the return oil flow rate by slightly changing the flow area of ​​the discharge valve port through a manual mechanical knob, thus strictly limiting the instantaneous descent speed to an extremely low range.

[0175] The high-pressure hydraulic oil in the hydraulic cylinder flows slowly back to the oil tank of the manual booster pump station through the throttling channel, and the rear of the heavy equipment sinks smoothly. When the bottom surface of the rear of the heavy equipment is fully supported on the support pads, the system completes the first-stage hydraulic micro-motion sinking operation, and then the hydraulic claw jacks on both sides are pulled out from under the bottom beam.

[0176] For the pressure-holding and sealing mechanism of the check valve in the above-mentioned hydraulic system and the selection of the pressure-resistant and explosion-proof structure of the high-pressure flexible oil pipe, those skilled in the art can consult and configure it according to the hydraulic transmission system design specifications. The hydrodynamic sealing and pressure-bearing principles of the hydraulic components are well-known technologies in this field and will not be elaborated here.

[0177] After the first stage of the heavy equipment is positioned at the rear, the second stage involves replacing the front obstacle-crossing wheels and smoothly positioning the final stage of the machine. This mechanism for replacing the front obstacle-crossing wheels and smoothly positioning the final stage includes the following steps:

[0178] S1201, locate the hydraulic stress point of the front bottom beam of the heavy equipment. Two additional sets of hydraulic lifting components are positioned on both sides of the front bottom beam of the heavy equipment. The specific lower features of the hydraulic lifting components described here are consistent with those of the rear, including hydraulic claw jacks. The operator uses a high-pressure pump station to input pressurized oil into the hydraulic claw jacks. The bearing claws of the hydraulic claw jacks rise upwards, supporting the front bottom beam of the heavy equipment. The front bottom surface of the heavy equipment moves away from the bearing surfaces of the two obstacle-crossing tank trolleys, relieving the normal load borne by the obstacle-crossing tank trolleys.

[0179] S1202, dismantle the rigid transverse connector and remove the front end of the machine. Release the rigid transverse connector between the two obstacle-crossing tank trolleys, severing the mechanical constraints between the left and right obstacle-crossing tank trolleys. Pull the two obstacle-crossing tank trolleys out of the gaps at the bottom front of the heavy equipment, removing them from the confined working area.

[0180] S1203, Configure the front permanent support assembly. The front permanent support assembly is placed in the space left after the obstacle-crossing tank vehicle withdraws. Specific features of the front permanent support assembly include adjustable anchor bolts and heavy-duty shock-absorbing pads. The adjustable anchor bolts are screwed into pre-drilled threaded holes at the bottom of the heavy equipment. Heavy-duty shock-absorbing pads are placed on the ground directly below the adjustable anchor bolts, aligning the axis of the adjustable anchor bolts with the center point of the heavy-duty shock-absorbing pads in the vertical direction.

[0181] S1204, Establish a geometric motion model for the micro-motion and settlement of the entire machine attitude and execute descent intervention. The system obtains the horizontal span from the rear support center of the heavy equipment after it has been positioned to the action center of the front hydraulic claw jack, and monitors the instantaneous longitudinal descent displacement variable of the front hydraulic claw jack caused by the leakage of hydraulic oil.

[0182] During the sinking process, the heavy equipment undergoes rigid body pitch angle deflection with the rear support point as the reference. Based on the geometric trigonometric function relationship under the small angle approximation condition, the system converts the ratio of the instantaneous longitudinal downward displacement variable at the front end to the horizontal span into the change in the longitudinal tilt angle of the entire heavy equipment.

[0183] The system has a preset maximum allowable tilt angle change rate threshold. Operators fine-tune the hydraulic oil discharge flow rate by adjusting the return valve of the manual booster pump station, thereby limiting the derivative of the instantaneous longitudinal descent displacement variable with respect to time. This operation ensures that the overall longitudinal tilt angle change rate of the heavy equipment is always less than the maximum tilt angle change rate threshold, preventing relative displacement or stress concentration in the internal structural components of the heavy equipment due to excessively rapid tilting caused by gravity.

[0184] S1205, complete the final stage load transfer and leveling control. Control the hydraulic claw jack to continuously and slowly retract. The front of the heavy equipment, carrying the adjustable anchor bolts, descends synchronously until the bottom surface of the adjustable anchor bolts contacts the upper surface of the heavy-duty shock-absorbing pads. Observe the pressure gauge of the manual lifting pump station; when the pressure gauge reading reaches zero, confirm that the weight of the front of the heavy equipment has been completely transferred to the front permanent support component. Remove the hydraulic claw jack from under the base beam. Use a torque wrench to rotate the adjusting nuts on the adjustable anchor bolts to change the height of the four corners of the heavy equipment, completing the fine-tuning of the equipment's level and securing it in place.

[0185] Regarding the self-locking anti-loosening mechanism of the adjustable anchor bolts and the compressive yield strength verification of the polymer rubber material inside the heavy-duty damping pad, those skilled in the art can perform parameter selection calculations according to the conventional installation specifications of mechanical equipment. The static damping and geometric leveling principles are well-known technologies in this field and will not be elaborated here.

[0186] Specific application examples:

[0187] This embodiment takes the transportation of a 110kV power transformer with a total mass of 25,000kg (approximately 245,000N) in an underground substation as an example. The width of the confined space passage is 2.8m, the width of the transformer body is 2.2m, the operating clearance on both sides is extremely small, the ground material is epoxy flooring, and there are local rubber protective pads for cable crossings.

[0188] The equipment system parameters are configured as follows:

[0189] Electric differential traction host drive wheel operating radius =0.15m, left and right wheel track span =0.8m, system safety margin factor =0.85.

[0190] During the initial handling phase, the transformer was hoisted onto a triangular three-point support system. The system was set to a minimum safe load percentage threshold of 0.3. The pressure sensing module measured the initial normal static load at 75,500 N.

[0191] The theoretical safe load limit of the central processing unit is calculated to be 245,000N × 0.3 = 73,500N.

[0192] The measured value is 75,500N ≥ 73,500N. The Boolean check result is true, and the system unlocks the drive motor.

[0193] During the travel phase, when the front end of the transformer passes over the rubber protective pad, it causes a slight backward shift in the system's center of gravity, followed by a forward tilt. The load torque distribution module acquires the dynamic normal load at a frequency of 50Hz.

[0194] Suppose at a certain moment Normal load data The voltage instantly dropped to 60,000 N. The central processing unit then activated the equivalent coefficient of friction of the epoxy flooring. =0.5.

[0195] Based on the theoretical maximum permissible output torque control equation, the upper limit of torque at this moment is calculated:

[0196] =0.5×60,000×0.15×0.85=3,825N·m.

[0197] At this point, the operator needs to accelerate to get over the pad, and the push rod commands torque. Reaching 4,200 N·m. Due to > The system triggers a segmented cutoff control law, which forcibly clamps the actual target output torque of the drive motor at 3,825 N·m, thus suppressing the freewheeling and slippage of the drive wheels.

[0198] When entering a narrow bend, the operator issues a command for the longitudinal travel speed of the foundation. =0.2m / s, target yaw rate command =0.1 rad / s.

[0199] Calculated based on the differential kinematic model:

[0200] Target linear velocity of the left drive motor =0.2−0.1×(0.8 / 2)=0.16m / s;

[0201] Target linear velocity of the right drive motor =0.2+0.1×(0.8 / 2)=0.24m / s.

[0202] The differential speed on both sides generates lateral thrust, guiding the two obstacle-crossing tanks in front to smoothly navigate the curve along the prescribed arc.

[0203] In the final placement phase, a manual booster pump station (hydraulic oil density) is used. =870kg / m 3 (Using a hydraulic claw jack. Working pressure difference) =20MPa, flow coefficient =0.62. The operator fine-tunes the relief valve to adjust the instantaneous flow area. Maintain at 2×10 −6 m 2 .

[0204] Based on the micro-motion settling flow control model:

[0205] Instantaneous oil discharge flow rate .

[0206] The extremely low oil flow rate allows the hydraulic cylinder to descend at a speed of millimeters per second, enabling the transformer to smoothly land on the heavy-duty shock-absorbing pad and complete a high-precision, impact-free docking.

[0207] Experimental verification and effect comparison:

[0208] To verify the actual technical effect of the control method and system for heavy equipment in confined spaces provided by the present invention, a system comparison experiment was conducted in a test field simulating an underground substation passage.

[0209] Experimental conditions and subjects:

[0210] The experimental test object was a counterweight device with a total mass of 25,000 kg (25 tons), and its base geometry was consistent with that of a standard 110kV transformer. The width of the simulated test channel was limited to 2.8m, the ground base material was epoxy flooring, and three 8mm thick protective pads were manually set up along the route to simulate ground height differences.

[0211] Control group: A conventional electric motor traction vehicle with constant torque output and a hydraulic jack with ordinary mechanical valve depressurization were used for the positioning operation; when the vehicle veered off course, manual intervention with a crowbar was required to adjust the attitude of the bottom support trolley.

[0212] Experimental group: The heavy equipment control system described in this invention was used, with torque cutoff control based on dynamic normal load, dual-wheel differential heading correction, and hydraulic micro-motion settling function based on flow control model enabled throughout the process.

[0213] Anti-slip and traction performance verification:

[0214] This test examines the bottom-level traction stability of the two sets of equipment when continuously traversing obstacles with an 8mm height difference. A high-precision speed encoder and a Doppler laser velocimeter are installed at the drive wheel axle end to simultaneously collect the theoretical linear velocity of the wheels and the actual forward speed of the vehicle body, calculating the slip ratio and traction force.

[0215] Table 1. Test Data of Bottom Layer Traction and Anti-skid Performance

[0216] Evaluation indicators significance Control group (conventional tractor) Experimental group (system of this invention) Effect Comparison Transient peak slip Reflects the degree of wheel slippage when it exceeds the static friction limit. 18.5% 2.2% Reduced by 88.1% Number of slips Number of times the vehicle came to a complete stop due to a complete loss of driving force. 3 times 0 times Completely eliminate Average traction drop The decrease in actual traction force during slippage compared to the normal value 34.6% 3.5% Reduced by 89.8% Obstacle crossing time Time required to cross a single 8mm height difference 12.5s 4.2s Shortened by 66.4%

[0217] in conclusion:

[0218] Combining the data in Table 1 and the appendix Figure 10As can be seen, the dark gray dashed line representing the control group exhibited three transient slippage peaks of up to 18.5% when crossing the obstacle. This is because conventional tractor units cannot detect the transient drop in the normal load on the ground when the wheels run over the obstacle, and thus maintain the original command torque output. This results in the driving force momentarily exceeding the maximum static friction force on the ground, leading to three macroscopic slippages.

[0219] In contrast, the solid black line representing the experimental group remained extremely stable throughout, with the transient peak slip rate strictly suppressed within the microscopic elastic slip range of 2.2%. This demonstrates that the present invention, relying on a fundamental torque cutoff control law, synchronously reduces the upper limit of the motor output torque within a microsecond cycle, completely eliminating macroscopic slippage and reducing obstacle crossing time by 66.4%, thus ensuring continuous traction output under adverse road conditions.

[0220] Verification of accuracy in confined space trajectory tracking:

[0221] This step is conducted within an S-shaped bend passage measuring 20m in length and 2.8m in width. Using the centerline of the passage as the theoretical baseline, an external laser total station is used to track the coordinates of the geometric center of the counterweight equipment in real time, measuring the lateral deviation of its trajectory.

[0222] Table 2. Test Data of Trajectory Tracking and Correction Accuracy

[0223] Evaluation indicators significance Control group (routine procedure) Experimental group (system of this invention) Effect Comparison Maximum lateral trajectory deviation Maximum distance from the theoretical baseline 145mm 12mm An increase of 91.7% Average trajectory tracking error Arithmetic mean of the absolute value of the lateral deviation throughout the entire process 42.6mm 4.1mm An increase of 90.3% Number of manual interventions The number of times the machine needs to be stopped and the trolley manually adjusted during operation. 5 times 0 times Automation replacement Yaw rate limiter triggered Protection against front-end sideslip caused by excessive correction This function is not available. 7 times Elimination of sideslip risk

[0224] in conclusion:

[0225] Combining the data in Table 2 and the appendix Figure 11 As can be seen, the dark gray dotted line representing the control group exhibits a large-scale jagged line, with a maximum lateral deviation of 145mm. This is because in extremely confined spaces, traditional equipment cannot achieve continuous turning. It requires five stops and manual prying to change the angle of the carrying trolley, which is not only extremely inefficient but also poses a serious risk of colliding with the passageway walls.

[0226] The solid black line representing the experimental group exhibits a very small amplitude of smooth sinusoidal fluctuation, closely adhering to the light gray theoretical baseline at the 0 mark throughout, with a maximum deviation of only 12mm. This fully verifies that the invention, based on the dual-wheel differential kinematic model and continuous transmission of thrust vector, replaces manual intervention, achieving precise autonomous correction in narrow passages, and the yaw rate limiting function ensures no risk of front-end sideslip.

[0227] Final placement mechanical impact verification:

[0228] This test measures the stress state of the equipment the instant it descends from the support platform onto the anchor blocks. Triaxial high-frequency accelerometers (sampling frequency 2000Hz) are installed at the four corners of the load-bearing base beam of the counterweight equipment to record the transient mechanical acceleration along the Z-axis at the moment of impact.

[0229] Table 3. Test Data of Landing Sinking and Mechanical Impact

[0230] Evaluation indicators significance Control group (conventional hydraulic valves) Experimental group (system of this invention) Effect Comparison Z-axis transient impact acceleration Peak impact on the device body at the moment of ground contact 1.85g 0.08g Reduced by 95.6% Hydraulic cylinder sinking flow rate control Average descent speed during landing 45.0 mm / s (stall) 1.5mm / s (controlled) Reduced by 96.6% Overall longitudinal tilt angle change rate The degree of attitude change during the transition between unloading and unloading 1.25° / s 0.05° / s Attitude and height stability Final horizontal alignment error Distribution of height differences at the four corners of the shim 2.5mm 0.3mm Meets high-precision installation requirements

[0231] in conclusion:

[0232] Combining the data in Table 3 and the appendix Figure 12 It can be seen that during the placement operation... At 0.5s (the instant of impact), the dark gray dashed line representing the control group exhibited a violent oscillation peak of up to 1.85g. This is because when a normal mechanical valve opens to release pressure, gravity causes the hydraulic oil to flow back out of control, resulting in a local stall and sinking of the equipment at a speed of up to 45.0mm / s, generating a highly destructive mechanical impact.

[0233] Conversely, the solid black line representing the experimental group at the moment of ground contact ( At 0.5s, there was almost no significant jump, and the impact acceleration was only 0.08g with rapid convergence. This proves that the present invention establishes a micro-motion return oil model by changing the flow area of ​​the bleed valve orifice, strictly and stably limiting the sinking velocity to an extremely low level of 1.5mm / s, thus achieving a shock-free flexible handover. At the same time, the tilt angle change rate is controlled at 0.05° / s, and the final horizontal alignment error is reduced to within 0.3mm, protecting the internal structure of high-precision heavy equipment and meeting the demanding high-precision installation requirements.

Claims

1. A method for controlling heavy equipment in confined spaces, characterized in that, Includes the following steps: The electric differential traction host and two obstacle-crossing tank trolleys are placed on the load-bearing platform under the heavy equipment in a three-point support topology. The initial normal static load data is obtained by the pressure sensing module on the electric differential traction host, and the bearing torque verification is performed based on the initial normal static load data. Under the condition that the verification is passed, the hardware and software locks on the drive motors inside the electric differential traction host and distributed on both sides are released. The system receives dynamic normal load data collected by the pressure sensing module during travel, performs a cutoff and limitation calculation on the output torque of the drive motor based on the dynamic normal load data, and applies the result to the drive motor. After the electric differential traction host and the heavy equipment are driven by the drive motor to reach the predetermined position, the heavy equipment is lifted by the hydraulic claw jack located at the rear end. After the electric differential traction host and the obstacle crossing tank trolley are moved out, the hydraulic claw jack is controlled to retract, so that the heavy equipment completes the placement operation.

2. The method for controlling heavy equipment in confined spaces according to claim 1, characterized in that, The method of placing the electric differential traction host and two obstacle-crossing tank trolleys in a three-point support topology on the support platform under the heavy equipment includes: The electric differential traction host is used as a single-point support structure at the rear, and the two obstacle-crossing tank trolleys are used as a double-point support structure at the front, forming a triangular three-point support layout at the bottom of the heavy equipment. A rigid lateral connector is installed between the two obstacle-crossing tank trolleys to lock the two obstacle-crossing tank trolleys into a synchronized motion unit.

3. The method for controlling heavy equipment in confined spaces according to claim 1, characterized in that, The initial normal static load data is obtained through the pressure sensing module on the electric differential traction host, including: The electrical signal output by the pressure sensing module is converted into a digital quantity to generate the original normal load data sequence; A sliding filter window is established, the original normal load data within the sliding filter window is extracted, the arithmetic mean is calculated, and the original normal load data sequence is transformed into an effective filtered normal load data sequence. The variance value extracted from the effective filtered normal load data sequence within a set time span is compared with the system's preset steady-state tolerance threshold to obtain the initial normal static load data.

4. The method for controlling heavy equipment in confined spaces according to claim 1, characterized in that, Based on the initial normal static load data, a bearing torque verification is performed. If the verification passes, the hardware and software locks on the drive motor are released, including: The initial normal static load data is logically compared with the theoretical safe bearing limit value; Under the condition that the initial normal static load data is not less than the theoretical safe bearing limit value and a Boolean result is generated as true, a high-level signal is output to the enable control pin of the motor drive module to connect the main power supply circuit of the drive motor, and a status ready command message is sent to the wireless remote control terminal through the wireless communication module. If a Boolean result is generated that is determined to be false, the sustaining voltage is cut off to the electromagnetic brake located on the output shaft of the drive motor, thereby locking the motor shaft.

5. A method for controlling heavy equipment in confined spaces according to claim 1, characterized in that, Receive dynamic normal load data from the pressure sensing module during travel, and perform a cutoff and limitation calculation on the output torque of the drive motor based on the dynamic normal load data to obtain the result, including: The dynamic normal load data is obtained by analog-to-digital conversion using a fixed sampling period; Receive the entered floor type code, and call the friction coefficient lookup table to extract the equivalent friction coefficient that matches the floor material; Read the actual operating radius of the drive wheel of the electric differential traction host; A physical benchmark model for limiting torque is established by combining the dynamic normal load data, the equivalent friction coefficient and the actual operating radius, and the theoretical maximum allowable output torque is calculated based on the physical benchmark model as the basis for the calculation.

6. The method for controlling heavy equipment in confined spaces according to claim 1, characterized in that, Based on the dynamic normal load data, a truncation and limitation calculation is performed on the output torque of the drive motor to obtain the result, and the result is applied to the drive motor, including: Calculate the desired command torque; The commanded torque and the theoretical maximum allowable output torque calculated based on the dynamic normal load data are imported into the comparison register for logical branch judgment, and the actual target output torque of the drive motor is calculated as the result. Under the condition that the commanded torque is less than or equal to the theoretical maximum allowable output torque, the commanded torque is input into the motor drive control loop; When the commanded torque is greater than the theoretical maximum allowable output torque, the commanded torque is truncated, and the theoretical maximum allowable output torque is used as the actual target output torque and input into the motor drive control loop.

7. The method for controlling heavy equipment in confined spaces according to claim 1, characterized in that, The electric differential traction host and the heavy equipment are driven by the drive motor to reach a predetermined position, including: Receive steering correction commands and parse the target yaw rate command and the basic longitudinal travel speed command; Extract the wheelbase span between the left and right drive wheels of the electric differential traction host; Based on the dual-wheel differential kinematic model, and combined with the wheel track span, the basic longitudinal travel speed command and the target yaw rate command are calculated in the forward direction to obtain the target linear velocity of the left drive motor and the target linear velocity of the right drive motor.

8. A method for controlling heavy equipment in confined spaces according to claim 1, characterized in that, Before removing the electric differential traction host and the obstacle-crossing tank vehicle, the method further includes: Send speed signals with equal amplitude and opposite direction to the drive motors on the left and right sides of the electric differential traction host; When the longitudinal axis of the electric differential traction host forms a 90° perpendicular angle with the longitudinal axis of the heavy equipment, the output speed signal stops; The rotational torque and the equivalent rotational resistance torque are established and compared. Under the condition that the rotational torque is greater than the equivalent rotational resistance torque, the rear end of the heavy equipment begins to perform planar tail-swing rotational motion with the virtual rotation center as the center.

9. A method for controlling heavy equipment in confined spaces according to claim 1, characterized in that, After removing the electric differential traction host and the obstacle-crossing tank trolley, control the hydraulic claw jack to retract, allowing the heavy equipment to complete the placement operation, including: Control the electric differential traction host to drive out from under the heavy equipment; A support pad is laid in the area directly below the electric differential traction unit after it has been removed. Fine-tuning the drain valve on the manual lifting pump station connected to the hydraulic claw jack changes the flow area of ​​the drain valve port, dynamically controlling the return oil flow rate to limit the instantaneous descent speed of the internal cylinder of the hydraulic claw jack. The high-pressure hydraulic oil in the internal cylinder of the hydraulic claw jack is controlled to flow slowly back to the oil storage tank of the manual lifting pump station through the throttling channel, so that the rear of the heavy equipment sinks smoothly and the bottom of the rear of the heavy equipment is completely supported on the support pad.

10. A control system for heavy equipment in confined spaces, applied to the control method for heavy equipment in confined spaces as described in any one of claims 1-9, characterized in that, include: Electric differential traction host, two obstacle-crossing tank trolleys, pressure sensing module, central processing unit, load torque distribution module, drive motor and hydraulic claw jack; The electric differential traction host and the two obstacle-crossing tank trolleys are placed under the heavy equipment in a three-point support topology to support the heavy equipment. The pressure sensing module is communicatively connected to the central processing unit and is used to acquire initial normal static load data; The central processing unit performs a load-bearing torque verification based on the initial normal static load data, and releases the hardware and software lock on the drive motor if the verification passes. The load torque distribution module is communicatively connected to the central processing unit and is used to receive dynamic normal load data from the pressure sensing module during the travel process, perform a cutoff and limitation calculation on the output torque of the drive motor based on the dynamic normal load data to obtain the result, and apply the result to the drive motor through the central processing unit. Based on the result, the drive motor drives the electric differential traction host and the heavy equipment to the predetermined position; The hydraulic claw jack located at the rear end is used to lift the heavy equipment and retracts in a controlled manner after the electric differential traction host and the obstacle-crossing tank trolley are removed, so that the heavy equipment can be placed in its position.

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