A control method for adaptive charging of an electric fork truck

Abstract

This invention discloses a control method for adaptive charging of an electric forklift. The control method includes the following steps: Step 1: The hydraulic pressure value of the lifting cylinder is acquired in real time through the pressure detection unit and filtered; Step 2: The current load weight is calculated based on the filtered hydraulic pressure value of the lifting cylinder through the stability analysis module; By incorporating the actual load weight of the chassis and the combined center of gravity height into the control through the pressure detection unit and the stability analysis module, a strong interlock between the vehicle's physical dynamics attitude and the high-power charging circuit is achieved, eliminating the risk of rollover caused by heavy loads, uneven ground, or secondary illegal stacking.

Description

Technical Field

[0001] This invention relates to an adaptive charging control method for electric forklifts, belonging to the field of forklifts. Background Technology

[0002] With the rapid development of industrial automation and intelligent manufacturing, electric forklifts have been widely used in warehousing and logistics. To maintain uninterrupted and efficient operation, forklifts are typically equipped with high-power, fast, automatic charging stations. When the battery level drops below a set value, the forklift will automatically drive into the charging station for rapid, high-current charging.

[0003] However, when existing forklifts are performing automatic charging, they often still carry heavy loads or are in a non-nominal state where they are not fully unloaded; especially when the goods are too far from the rack or unloading rack, some drivers will not charge the forklifts while carrying the goods as required.

[0004] Existing charging systems only perform safety checks on the battery's chemical properties such as voltage, temperature, and current, lacking real-time monitoring of the forklift chassis's physical and dynamic states. If a forklift is charged with a high current under heavy load, when the mast is tilted forward, or when it is parked on a slope or in a collapsed area causing the vehicle to tilt, it is extremely easy for the vehicle to overturn due to even slight external disturbances. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a control method for adaptive charging of electric forklifts, thereby solving the problem.

[0006] To achieve the above objectives, the present invention provides a control method for adaptive charging of an electric forklift, wherein the forklift includes: The pressure detection unit is used to detect the hydraulic pressure value of the lifting cylinder in real time. The stability analysis module is used to calculate the stability coefficient of the forklift in real time. ; The safety control module is used to perform operational protection during operation and driving conditions. The charging safety linkage module is used to generate charging control commands during charging. The control method includes the following steps: Step 1: The hydraulic pressure value of the lifting cylinder is acquired in real time through the pressure detection unit and then filtered. Step 2: Calculate the current load weight using the stability analysis module based on the filtered hydraulic pressure value of the lifting cylinder; Step 3: Based on the current load weight, calculate the stability coefficient of the forklift in its current state. ; Step 4: Identify the current operating condition of the forklift in real time; If the condition is identified as a working driving condition, then the stability coefficient will be... With the preset first safety threshold Perform a comparison; If the condition is identified as a charging state, then the stability coefficient will be... With the preset second security threshold Perform a comparison; Step 5: Based on the comparison results from Step 4, implement the corresponding tiered security protection: Under the aforementioned operating conditions, if the stability coefficient Below the first safety threshold Then, at least one of the following operational protection actions—vehicle speed limiting, gantry movement locking, and local audible and visual alarm—is executed through the operational safety control module. Under the charging condition, if the stability coefficient Below the second safety threshold If the forklift is found to be in a charging instability state, the charging safety linkage module will generate a charging prohibition command or a charging cut-off command to prevent external charging equipment from starting charging or to cut off the current charging output.

[0007] Preferably, the pressure detection unit includes a lifting pressure sensor disposed on the lifting cylinder.

[0008] Preferably, the operation safety control module is electrically connected to the pressure detection unit and the stability analysis module, and is used to receive the stability coefficient calculated by the stability analysis module. And execute the operation protection actions.

[0009] Preferably, the operation safety control module is communicatively connected to the stability analysis module; the charging safety linkage module is communicatively connected to the stability analysis module.

[0010] Preferably, the stability analysis module uses the following formula when calculating the current load weight:

[0011] Where, in the formula, The current load weight. This refers to the hydraulic pressure value of the lifting cylinder. This refers to the effective area of ​​the rodless chamber of the lifting cylinder. This refers to the inherent friction of the gantry and hydraulic cylinder. Due to the inherent mass of the forks, This is the acceleration due to gravity.

[0012] Preferably, the charging safety linkage module includes a software control unit and a hardware circuit breaker unit; step five, cutting off the currently ongoing charging output, specifically includes: The software control unit is configured to send a soft-cut-off command to the external charger via the CAN bus to reduce the charging current of the external charger. The hardware circuit breaker unit drives the safety trip contactor connected in series in the charging circuit to physically disconnect the main charging circuit.

[0013] Preferably, the control method further includes a fault self-diagnosis step: the stability analysis module monitors the signal status of the pressure detection unit in real time, and when it detects a signal interruption, short circuit, or abnormal value in the pressure detection unit, it defaults to setting the stability coefficient... Assign a safety lock value of zero and forcibly trigger the charging safety linkage module to perform charging prohibition or charging cut-off actions.

[0014] Preferably, the first security threshold and the second security threshold The safety threshold is dynamically set based on the forklift's center of gravity height and physical wheelbase, and the first safety threshold is... Greater than the second security threshold .

[0015] Preferably, the first security threshold With the second security threshold The calculation formulas are set as follows:

[0016]

[0017] in, Let the height be the combined center of gravity of the forklift and the cargo, and satisfy the following:

[0018] in, The unloaded vehicle body mass, The height of the vehicle's center of gravity. The current load weight. Lifting height To achieve the maximum design deceleration, It is the acceleration due to gravity. This refers to the physical wheelbase of the forklift. This is the redundancy factor for vibration caused by driving. For the permissible ground limit dip angle, This is the redundancy coefficient for static charging instability protection.

[0019] Preferably, in step three, the stability coefficient The specific calculation method is as follows:

[0020] in, This refers to the inherent stabilizing torque generated by the vehicle's own weight behind the main axle. The torque is the force generated by the current load weight.

[0021] Beneficial effects This invention incorporates the actual load weight of the chassis and the combined center of gravity height into the control through a pressure detection unit and a stability analysis module, thereby achieving a strong interlock between the vehicle's physical dynamics attitude and the high-power charging circuit, eliminating the risk of rollover caused by heavy loads, uneven ground, or secondary illegal stacking. This invention can identify operating conditions and charging conditions, and adaptively match a first safety threshold and a second safety threshold; it also considers corresponding response strategies for each operating condition. Attached Figure Description

[0022] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a flowchart illustrating the adaptive charging control method for an electric forklift according to the present invention. Detailed Implementation

[0023] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0024] Please see Figure 1 This invention provides a control method for adaptive charging of an electric forklift: the forklift includes: The pressure detection unit includes a lifting pressure sensor installed in the rodless chamber of the lifting cylinder, used to detect the original hydraulic pressure signal of the lifting cylinder in real time.

[0025] The stability analysis module, typically integrated into the vehicle's main vehicle control unit (VCU), is primarily used to calculate and interpret the current physical stability coefficients of the forklift chassis in real time. .

[0026] The operation safety control module is used to implement safety measures such as speed limits and gantry locking during operation.

[0027] The charging safety linkage module is used to establish a safety linkage with external charging equipment (such as automatic charging piles) during charging. It includes a safety trip contactor for physically cutting off the high-voltage circuit and a controller CAN bus communication interface.

[0028] The control method includes the following steps: Step 1: When a forklift is stationary during lowering, raising, or bumpy movement, brief valve spurts and hydraulic shocks (i.e., high-frequency pressure jitter) often occur in the lifting cylinder. After the pressure detection unit acquires the raw electrical signal from the lifting pressure sensor, the stability analysis module executes a low-pass filtering algorithm or a moving average (sliding average) filtering algorithm. In this embodiment, the filtering and de-jittering time window is set to 500ms (adjustable between 300ms and 800ms depending on the forklift's inertia), smoothly filtering out the pressure overload caused by the instantaneous valve movement.

[0029] Step 2: The stability analysis module reads the static hydraulic pressure value obtained after filtering. The actual mass of the load on the forklift forks is calculated using the following mechanical formula. :

[0030] In this embodiment, the effective force-bearing area of ​​the rodless chamber of the lifting cylinder is set. Approximately 0.005m 2 The inherent friction between the gantry and piston seals The inherent mass of the forks and attachments is set at 180N. Gravitational acceleration Using 9.8m / s 2 .

[0031] Step 3: Based on the calculated load mass Calculate the current stability of the vehicle. Stability coefficient. The specific calculation formula is as follows:

[0032] In the formula, This is the inherent stabilizing torque generated by the vehicle's own weight on the rear axle (this value is a constant, determined at the factory by the forklift's own chassis weight and physical center of gravity). Based on the current load weight The resulting overturning moment. When The smaller the value, the closer the overturning moment at the pivot point is to the stability moment limit, and the easier it is for the vehicle to tip forward.

[0033] Step 4: The Vehicle Control Unit (VCU) identifies the forklift's current operating status in real time by monitoring the vehicle's motor speed, speed encoder signal, and the level status of the external charging detection lines (CC1 / CC2 signals). Under operating conditions: the stability coefficient calculated in step three... With the preset first safety threshold Compare them.

[0034] Under automatic charging conditions: the stability coefficient With the preset second security threshold Compare them.

[0035] Because vehicles experience dynamic vibrations and acceleration / deceleration inertial torques while in motion, their risk of rollover is higher. Therefore, the first safety threshold is set higher than the second safety threshold. This ensures sufficient safety margin while in motion, while also preventing false alarms due to excessive sensitivity during static charging.

[0036] Step 5: During operation: If the current driving condition is detected... When the speed is less than 1.25, the safety control module immediately forces the upper limit speed of the vehicle's drive wheels to be reduced from 1.5m / s to below 0.3m / s. At the same time, it sends a locking signal to the multi-way valve controller to physically lock the forward tilt of the mast and the continued upward lifting of the forks, and controls the local audible and visual alarm on the vehicle body to emit a red flashing signal.

[0037] Under automatic charging conditions: The external charging station begins high-voltage DC fast charging. If, during charging, a sudden change in stability occurs... <1.15 (e.g., due to the ground being soft and sinking, the static rollover angle of the vehicle suddenly increases, or other handling equipment or on-site personnel illegally place heavy-loaded goods on the forks of a forklift that is parked and charging, causing serious human overloading).

[0038] The charging safety linkage module determines that the vehicle is in a charging instability state and generates and executes a two-level cut-off control command: Level 1: The charging safety linkage module sends a high-priority emergency current reduction protocol to the external charging equipment (automatic charging pile) via the CAN bus, requiring the charging pile to reduce the input charging current from 150A to a safe current (2A) in a stepwise manner within 80ms.

[0039] Level Two: After the current drops to a safe value, the hardware circuit breaker unit in the charging safety linkage module disconnects the safety trip contactor connected in series with the main positive terminal of the charging circuit, physically cutting off the main charging circuit. This mechanism greatly avoids the phenomenon of contactor arcing and burning due to direct disconnection under a large current of hundreds of amperes, ensuring a long lifespan for the hardware circuit.

[0040] The operational safety control module and the lifting pressure detection unit mentioned in this technical solution are electrically connected; the stability analysis module communicates bidirectionally with the stability analysis module through a high-speed controller area network (CAN bus); the charging safety linkage module is also connected to the stability analysis module in real time, thereby realizing a strong interlock between the vehicle's physical sensor data and the terminal high-voltage high-power charging power supply circuit.

[0041] To prevent malfunctions, wire breaks, or manual removal of the lifting pressure sensor during charging, the stability analysis module has a real-time fault self-diagnosis mechanism. The control method also includes a fault self-diagnosis step: once a sudden change in the pressure signal to zero, open circuit, short circuit, or abnormal value (such as a momentary jump to a physically unreasonable value) is detected, the system immediately triggers fault safety logic: by default, the current stability coefficient is set to zero. Forcibly assigning a value of zero ( =0). Because =0 is definitely lower than the second safety threshold for charging. The system will immediately trigger the charging safety linkage module to perform charging cut-off and prohibition actions to prevent the chassis protection strategy from failing due to sensor damage.

[0042] Working principle During normal vehicle operation and automatic charging at charging stations, the control system continuously monitors the actual load status on the forklift forks and performs high-precision slip vibration reduction using physical pressure sensors located at the front end of the fork hydraulic circuit. The stability analysis module integrates the collected dynamic / static pressure values ​​into the chassis dynamics mathematical model to calculate in real time the stability coefficient that accurately characterizes the risk of vehicle rollover and instability. .

[0043] By automatically identifying dynamic and static scenarios such as "operational driving" and "charging," different safety warning thresholds are adaptively matched. During charging, if the vehicle's chassis stability approaches the rollover threshold due to various external physical disturbances (such as secondary overload, ground tilt, or settlement), the linkage module achieves a chain-like strong cut-off at both the software current reduction and hardware contactor disconnection levels. This forcibly stops the high-current charging before the forklift rolls over, thereby eliminating the fundamental hidden dangers of forklift charging instability under heavy load, rollover squeezing of lithium batteries, and subsequent electrochemical thermal runaway fires. This significantly improves the inherent safety of industrial production in smart warehousing and logistics parks.

[0044] To achieve highly reliable linkage during operation and charging, the core of this control method lies in dynamically adjusting the safety judgment limits based on the physical structural characteristics of the forklift. First safety threshold. (Driving conditions) and the second safety threshold (Charging conditions) are determined by the vehicle's combined center of gravity height. and wheelbase Dynamic coupling determines this. Its physical derivation is as follows: In step five, after the vehicle picks up the goods, the height of the common center of gravity of the forklift and the goods will shift in real time as the goods are lifted and the load changes.

[0045]

[0046] in, The unloaded vehicle body mass, The height of the vehicle's center of gravity. The lifting height is provided in real time by a laser cable sensor mounted on the gantry (if a height sensor is not selected, the system defaults to the highest rated lifting constant value). = =3.0m for the most conservative and safest calculation).

[0047] During operation, the forklift faces emergency braking deceleration and bumps caused by road undulations. Assume the vehicle's maximum design deceleration is... (In one embodiment, it is set to 1.5 m / s) 2 ), gravitational acceleration =9.8m / s 2 Forklift physical wheelbase =1.4m (horizontal wheelbase from front wheel to rear wheel).

[0048] To ensure that the vehicle's dynamic rollover coefficient is greater than the safety lower limit of 1.0 during emergency braking, according to d'Alembert's principle, the equivalent driving stability limit under static indicators is:

[0049] in This is the redundancy factor for vibration caused by driving bumps (set to 0.08 in this embodiment). The ratio in the formula... This intuitively reflects the mechanical hazard ratio of a "top-heavy" structure, when the combined center of mass is high. Higher, wheelbase The shorter the time, the lower the driving threshold. It will automatically and dynamically rise, thereby forcibly limiting its maximum speed and activating the speed limit and gantry locking protection in advance.

[0050] Under static charging conditions, the vehicle does not have deceleration inertia (i.e., =0). However, due to the possibility of slight unevenness or subsidence on the ground in the automatic charging docking area (the maximum allowable ground inclination angle is...), In this embodiment, the extreme slope angle of the ground where the charging pile is parked is... =3.0°), at this tilt angle, gravity will produce a forward tilting component. Considering potential static roll disturbances, the instability limits are derived as follows:

[0051] in The redundancy factor for static charging instability protection is set to 0.04 in this embodiment.

[0052] Due to the proportion of inertial force generated by the maximum deceleration during travel = It is significantly greater than the maximum allowable sine slope angle for static charging. 0.052, and the vibration fluctuation redundancy coefficient under driving conditions is greater than the static redundancy ( =0.08> =0.04). This can be derived and proven from a physical and mechanical perspective: under any load and lifting height condition, the first safety threshold under driving conditions is... It will inevitably dynamically exceed the second safety threshold under charging conditions. (Right now > This ensures that static charging will not be accidentally disconnected due to minor mechanical vibrations, while also guaranteeing a highly redundant anti-rollover warning system during driving conditions.

[0053] Example 1 In this embodiment, the electric forklift (AGV) drives into the fast automatic charging station of the smart warehousing and logistics park in an unloaded state and connects with the external charging pile. The main charging circuit is connected, and the charging pile outputs high-voltage DC power. The initial charging current is set to 150A in high-power fast charging mode.

[0054] After charging begins, the specific control process of the system is as follows: The lifting pressure sensor monitors the pressure in the rodless chamber of the lifting cylinder in real time, and the stability analysis module obtains the static pressure through mean filtering with a sliding time window of 500ms. =0.35MPa (equivalent to approximately the weight of the empty forklift and forks). The actual fork load is calculated using the formula. kg (unloaded).

[0055] The stability analysis module reads data from the laser height sensor. At this time, the forks are at the bottom position, and the cargo lifting height is... =0.1m, self-weight of the load =0kg. Calculated using the formula:

[0056] The system identifies that the external charging detection line (CC2 signal) is currently in a high-level connection state, determines it as a "static charging condition," and automatically adjusts the charging status based on the center of gravity height. =0.60m to calculate the second safety threshold :

[0057] The stability analysis module calculates the stability coefficient of the currently unloaded chassis under static conditions. =1.65. Due to the current stability coefficient... =1.65≥1.062, the system determines that the current chassis status is stable, and generates and maintains a charging permission command through the charging safety linkage module, and high-current fast charging continues.

[0058] Example 2 An electric forklift was found to be illegally carrying a heavy pallet before attempting to charge it.

[0059] The pressure sensor detects high-frequency pressure pulses in contact with the forks, with a maximum peak pressure of 3.5 MPa. The stability analysis module smoothly filters out the dynamic spikes caused by the heavy-load pallet landing within 500ms, and then reads the oil temperature and pressure values ​​after the pressure has stabilized. =2.45MPa. Solving using the formula:

[0060] (Note: Substitute the rodless cavity area into the formula here) =0.005m 2 Friction force 180N, fork inherent mass 150kg.

[0061] Real-time height detection of forks =0.6m, based on the current Substituting 1080kg back into the center of gravity model, we obtain the current combined center of gravity height of the vehicle. :

[0062] (Note: Although the center of gravity changes very little in the vertical direction, the forward tilting of the forks generates a forward tilting torque, resulting in a tipping moment.) The sudden increase leads to a decrease in the calculated stability coefficient. It quickly dropped to 1.05.

[0063] Recalculated static second security threshold It remains at 1.062. This is due to the current chassis stability coefficient. =1.05<1.062 (recalculated static charging threshold), the system determines that the vehicle has entered a charging instability state.

[0064] The charging safety linkage module immediately triggers a two-stage forced disconnection mechanism: the software control unit sends a highest-priority current reduction signal frame to the external charging pile via the CAN bus, which contains an emergency stop request. Upon receiving the signal, the external charging pile forcibly linearly reduces the main circuit output current from 150A to 1.8A within 65ms.

[0065] The moment the CAN bus feedback current drops to a safe value (below 2A), the hardware circuit breaker unit is triggered: the drive coil of the safety trip contactor is de-energized, the trip switch quickly opens, and complete high-voltage isolation is achieved at the physical level.

[0066] The local audible and visual alarm emits a high-frequency red flashing light and a buzzer alarm, and at the same time reports a serious chassis imbalance and instability fault to the vehicle dispatch system (RCS). The whole vehicle enters a fault protection deadlock state to prevent the battery from colliding and catching fire when it rolls over while on the verge of instability.

[0067] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0068] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A control method for adaptive charging of an electric forklift, characterized in that: The forklift includes: The pressure detection unit is used to detect the hydraulic pressure value of the lifting cylinder in real time. The stability analysis module is used to calculate the stability coefficient of the forklift in real time. ; The safety control module is used to perform operational protection during operation and driving conditions. The charging safety linkage module is used to generate charging control commands during charging. The control method includes the following steps: Step 1: The hydraulic pressure value of the lifting cylinder is acquired in real time through the pressure detection unit and then filtered. Step 2: Calculate the current load weight using the stability analysis module based on the filtered hydraulic pressure value of the lifting cylinder; Step 3: Based on the current load weight, calculate the stability coefficient of the forklift in its current state. ; Step 4: Identify the current operating condition of the forklift in real time; If the condition is identified as a working driving condition, then the stability coefficient will be... With the preset first safety threshold Perform a comparison; If the condition is identified as a charging state, then the stability coefficient will be... With the preset second security threshold Perform a comparison; Step 5: Based on the comparison results from Step 4, implement the corresponding tiered security protection: Under the aforementioned operating conditions, if the stability coefficient Below the first safety threshold Then, at least one of the following operational protection actions—vehicle speed limiting, gantry movement locking, and local audible and visual alarm—is executed through the operational safety control module. Under the charging condition, if the stability coefficient Below the second safety threshold If the forklift is found to be in a charging instability state, the charging safety linkage module will generate a charging prohibition command or a charging cut-off command to prevent external charging equipment from starting charging or to cut off the current charging output.

2. The control method for adaptive charging of an electric forklift according to claim 1, characterized in that: The pressure detection unit includes a lifting pressure sensor installed in the lifting cylinder.

3. The control method for adaptive charging of an electric forklift according to claim 1, characterized in that: The operational safety control module is electrically connected to the pressure detection unit and the stability analysis module, and is used to receive the stability coefficient calculated by the stability analysis module. And execute the operation protection actions.

4. The control method for adaptive charging of an electric forklift according to claim 1, characterized in that: The operation safety control module is communicatively connected to the stability analysis module; the charging safety linkage module is communicatively connected to the stability analysis module.

5. The control method for adaptive charging of an electric forklift according to claim 1, characterized in that: The stability analysis module uses the following formula when calculating the current load weight: Where, in the formula, The current load weight. This refers to the hydraulic pressure value of the lifting cylinder. This refers to the effective area of ​​the rodless chamber of the lifting cylinder. This refers to the inherent friction of the gantry and hydraulic cylinder. Due to the inherent mass of the forks, This is the acceleration due to gravity.

6. The control method for adaptive charging of an electric forklift according to claim 1, characterized in that: The charging safety linkage module includes a software control unit and a hardware circuit breaker unit; step five, cutting off the currently ongoing charging output, specifically includes: The software control unit is configured to send a soft-cut-off command to the external charger via the CAN bus to reduce the charging current of the external charger. The hardware circuit breaker unit drives the safety trip contactor connected in series in the charging circuit to physically disconnect the main charging circuit.

7. The control method for adaptive charging of an electric forklift according to claim 1, characterized in that: The control method further includes a fault self-diagnosis step: the stability analysis module monitors the signal status of the pressure detection unit in real time, and when it detects that the pressure detection unit has a signal interruption, short circuit, or abnormal value, it defaults to setting the stability coefficient. Assign a safety lock value of zero and forcibly trigger the charging safety linkage module to perform charging prohibition or charging cut-off actions.

8. The control method for adaptive charging of an electric forklift according to claim 1, characterized in that: First security threshold and the second security threshold The safety threshold is dynamically set based on the forklift's center of gravity height and physical wheelbase, and the first safety threshold is... Greater than the second security threshold .

9. The control method for adaptive charging of an electric forklift according to claim 1, characterized in that: First security threshold With the second security threshold The calculation formulas are set as follows: in, Let the height be the combined center of gravity of the forklift and the cargo, and satisfy the following: in, The unloaded vehicle body mass, The height of the vehicle's center of gravity. The current load weight. Lifting height To achieve the maximum design deceleration, It is the acceleration due to gravity. This refers to the physical wheelbase of the forklift. This is the redundancy factor for vibration caused by driving. For the permissible ground limit dip angle, This is the redundancy coefficient for static charging instability protection.

10. The control method for adaptive charging of an electric forklift according to claim 1, characterized in that: In step three, the stability coefficient The specific calculation method is as follows: in, This refers to the inherent stabilizing torque generated by the vehicle's own weight behind the main axle. The torque is the force generated by the current load weight.

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