WO2022159638A1

WO2022159638A1 - Winch, rope, and operator safety scheme

Info

Publication number: WO2022159638A1
Application number: PCT/US2022/013207
Authority: WO
Inventors: Steven Alan GEBHART
Original assignee: Allied Motion Technologies Inc.
Priority date: 2021-01-20
Filing date: 2022-01-20
Publication date: 2022-07-28

Abstract

A controller for a winch may include a speed input configured to receive a speed signal corresponding to a speed of a motor of a winch, and a current sense input configured to receive a signal corresponding to a current of the motor. The controller may be configured to sample a speed signal from the speed input; sample a current signal from the current sense input; and determine if the winch is operating within pre-determined parameters based on the sampled speed signal and the sampled current signal. A method of controlling a winch may include receiving a speed signal corresponding to a speed of a motor of a winch; receiving a current signal corresponding to a current of the motor; and determining if the winch is operating within pre-determined parameters based on the received speed signal and received current signal.

Description

WINCH, ROPE, AND OPERATOR SAFETY SCHEME

Cross-Reference to Related Applications

[0001] This application claims priority to U.S. Provisional Application No. 63/139,738, filed on January 20, 2021, now pending, the disclosure of which is incorporated herein by reference.

Field of the Disclosure

[0002] The present disclosure relates to winches, and more particularly to controllers for winches.

Background of the Disclosure

[0003] A traditional battery-operated winch system may run in an open-loop manner, whereby the drive motor powering the rope recovery spool may deliver torque and speed given by the speed-torque characteristic of the winch system and the available battery voltage. The winch motor may be powered via a switch-controlled contactor to either winch in or winch out.

[0004] During a winching scenario, a load could exceed the capacity of the winch, leading to overheating of the motor, damage to the winch components, or rupture of the rope, any of which may be a safety hazard to the winch operator or any nearby observer.

[0005] When operating the winch within its rated capacity, the end of the rope (which may have a hook and a load attached to the hook) may be pulled up against the fairlead with the full power of the winch motor. This can cause damage to the fairlead, the winch, or the rope irreparably — or even catastrophically — if not stopped.

[0006] Typically, the winching process may be stopped by the winch operator upon noticing such a condition exists or a problem is imminent. This requires the focus of a trained operator to ease up on the winch control, which may be a control tethered (wired) to the winch, or wireless control (for example, a key fob, etc.)

[0007] Other systems may use a magnet, which is attached at or near the hook end of the rope (for example, using a rubber ring to hold the magnet in place). When such a magnet approaches the fairlead, a reed switch inside or near the fairlead opens to interrupt the circuit that controls the motor contactor, thereby stopping the winch. When this happens, the magnet must be manually pulled away from the fairlead to close the reed switch in order to resume the winching function.

[0008] There is a long-felt need for winches that do not require such operator focus, skill, and/or manual intervention in order to prevent damage.

Brief Summary of the Disclosure

[0009] Embodiments disclosed herein may implement programmable intelligence of a battery powered winch motor controller to detect, during a winching operation, when a winched load is normal, when the winched load exceeds the winch’s rated capacity, when the winched load is near the breaking strength of the rope, when the end of the rope has been reached, and/or when the rope has been bound.

Description of the Drawings

[0010] For a fuller understanding of the nature and objects of the disclosure, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:

Figure l is a block diagram of a winch according to an embodiment of the present disclosure;

Figure 2 is an example operator interface of a winch;

Figure 3 is an example flowchart according to another embodiment of the present disclosure; and Figure 4 depicts a method according to another embodiment of the present disclosure.

Detailed Description of the Disclosure

[0011] Unless otherwise stated, the terms “wire rope,” “rope,” and “cable” are used herein interchangeably to describe rope, cable, cord, of any diameter, monofilament or multifilament, and made from metal, plastic, natural materials, or other materials including combinations of materials.

[0012] In a typical winch, such as a vehicle-mounted winch, a rope recovery spool is driven by a motor. A rope is attached to the rope recovery spool and configured to be wound and unwound from the spool using the motor. The rope may be unwound, attached to a load, and then rewound onto the spool — thereby moving the load (or the vehicle to which the winch is affixed). By monitoring motor current, which is directly related to motor torque by the motor’s torque constant, the torque on the rope recovery spool can be determined. This torque may produce a force on the rope and the load as a function of the amount of rope coiled on the spool.

[0013] With a given winch configuration, the maximum amount of torque that should ever be required to winch the rated load can be determined. Additionally, the speed of the spool can be monitored to observe whether it is rotating or not. This may relate to a drive motor current value for torque, and to a drive motor speed value for spool speed after a reduction ratio, if any (e.g., via a gearbox, etc.)

[0014] During winching, the drive motor current can be monitored using (for example, a current sensing technique). Rotation of the spool can be also be monitored (for example, using an encoder, monitoring motor speed, etc.). In this way, one can determine:

(1) if the load is within the capacity of the winch, and the winch spool is turning;

(2) if the load exceeds the capacity of the winch, and the winch spool is turning;

(3) if the load is near the strength limit of the rope, and the winch spool is turning; or

(4) if the load is near the strength limit of the rope, and the spool is not turning.

[0015] By determining one or more of these values, a winch motor controller provide operational status indication to an operator. For example, the operator may receive indication as to whether or not the winching process is safe, whether or not the load is too large for normal operation, whether or not the output power of the winch motor will be reduced to keep the winch from overheating, etc. The operator may be alerted that the winch is being operated in an unsafe manner, that the end of the rope has been reached and winching will be stopped automatically, etc.

[0016] Having automatic sensing of the spool speed and torque, and an ability to automatically respond to certain conditions, may remove the dependency of winch operation from an un-focused or careless winch operator. This provides advantages including improving winch safety and protecting the winch hardware and rope. Embodiments herein may advantageously provide automatic winch component and rope protection, improved operator and near proximity observer safety, and operator feedback for safe and unsafe winching conditions to winch manufacturers and winch users who drive all-terrain vehicles, small trucks, and other offroad vehicles that may need winch recovery. [0017] An intelligently controlled winch motor may use a decision-based software process to detect certain motor conditions, provide output signals to control operator indicators, and change the functionality of the winch based on the outcomes of such decisions.

[0018] Sensor inputs for this decision-based process may include motor current and motor speed, both of which are directly proportional to the torque and speed of the rope recovery spool of the winch. The torque and speed of the spool is indirectly proportional to the force on the rope, and speed of the spool.

[0019] In some embodiments, the motor current may be sensed using a low resistance hardware element (e.g., a current sense resistor) in series with one of the leads of a brushed motor, or in any one of the three phases of a brushless motor inverter. The voltage across this resistive load is proportional to the current through it. In practice, some filtering of the measurement may be beneficial — e.g., to remove noise. Measurement of motor speed can be accomplished using any manner of encoders or other techniques, as is known in the art.

[0020] A controller may utilize the measured motor current and motor speed to identified one or more pre-determined conditions that require some action by the controller. For example, the controller may utilize software having case statements to address predetermined conditions. The controller may then take one or more appropriate actions such as, for example, alerting the operator to the status of the winch, executing the functions designed to protect the winch and the operator, etc.

[0021] The present disclosure may be embodied as a controller for closed-loop control of a winch. The controller includes a speed input configured to receive a speed signal corresponding to a speed of a motor of a winch. For example, the speed input may be configured to connect to an optical encoder of the motor. The controller also includes a current sense input configured to receive a signal corresponding to a current of the motor. For example, the current sense input may be configured to measure a voltage across a current sense resistor of the motor.

[0022] The controller is configured to sample a speed signal from the speed input and a current signal from the current sense input. The controller is configured (e.g., programmed) to determine if the winch is operating within pre-determined parameters based on the sampled speed signal and the sampled current signal. The pre-determined parameters may indicate the motor/winch operating within “normal” parameters (e.g., within the rating of the motor and/or other winch components). In some embodiments, the controller is further configured to provide a normal operation signal when the winch is operating within the pre-determined parameters. For example, the controller may cause an indicator to illuminate.

[0023] In some embodiments, the controller is further configured to determine if the winch is operating in a condition for overheating risk based on the sampled speed signal and the sampled current signal. For example, by relating motor current to torque by the torque constant of the motor and thereby calculating power as a function of torque and speed. Power in excess of a pre-determined design limit can then be reduced to lower a temperature rise. These power reductions can be stepped to further protect the winch as a function of duration of power application. In some embodiments, one or more temperature sensors (e.g., a thermocouples, etc.) may be placed on in locations of the winch which are prone to overheating. For example, thermocouples may be placed on a circuit board of an inverter of the winch, on the motor, and/or or in or on the motor windings. The controller may be configured to sample a temperature from each of the one or more temperature sensors and determine if the sampled temperature(s) exceed a pre-determined temperature threshold. The threshold may be set to a level such that the winch components (e.g., electronics, motor, etc.) are not damaged. If the threshold is reached, the controller may be configured to limit the motor current (torque) and/or spool speed, to reduce power into the winch.

[0024] In some embodiments, the controller is further configured to determine if the winch is operating in a stall condition based on the sampled speed signal and the sampled current signal. For example, if the spool speed is zero, and the motor is drawing maximum current, the winch can be considered stalled, and/or the load is up against the fairlead. The controller may be configured to detect this condition. The controller may be further configured with a timed duration of this condition so as to filter between instantaneous and short-lived events (e.g., overcoming a log or stone), from conditions where no motion exists for an extended period, suggesting stall.

[0025] In some embodiments, the controller is further configured to determine if the winch is operating at condition for winch damage or rope damage based on the sampled speed signal and the sampled current signal. For example, if the spool speed and motor torque (measured as current) exceed the design power level of the winch (a function of torque and speed), then conditions exist for damage or unsafe operation. This maximum power level is a pre-determined design parameter of the winch and can be set in the controller (e.g., established in software, firmware, etc.) If the maximum power level is exceeded, the controller may be configured to reduce power to the motor so as to allow continuation of the winching operation with reduced performance or until a stall condition is detected. In some embodiments, the controller may be configured to terminate the winching operation if the maximum power level is exceeded.

[0026] Figure 1 depicts a block diagram of an embodiment disclosure. A winch operator, by means of an operator control 1, may press a button to begin winching a load 7 attached to an end of the rope 6. The controller and software 2 may detect this command and turn on a drive motor 3. Drive motor 3 may drive a winch spool 5 through, or in parallel with, an encoder 4. Encoder 4 may send electronic signals to controller and software 2, which may determine the speed of winch spool 5. Controller and software 2 may also measure the voltage detected by voltage sensor 9 developed across the current sense 8, to determine the drive motor 3 torque. The controller and software 2 may then determine the necessary indications for the operator interface 10.

[0027] Figure 2 depicts an exemplary operator interface configured to indicate a status of the winch. Operator interface 10 may be integrated into a wired or wireless fob, displayed as a multi-color led or light on an instrument panel, shown on a physical gauge or meter on the instrument panel, graphically represented in a user interface driven by software, and/or communicated over a vehicle bus, such as controller area network (CAN) bus.

[0028] Operator interface 10 may thus alert the operator to the condition of the winching process, for example, by color and/or level on a gauge. Indicator 14 may be green and may indicate that the winch is operating normally. Indicator 13 may be yellow and may indicate that the winching power has been reduced to keep the winch from overheating but will continue to operate with reduced performance. Indicator 12 may be orange and may indicate that the load is unsafe, or that the rope can break, and that the winching function has been stopped. Indicator 11 may be red and may indicate that the load has been driven up to the fairlead, or the rope is bound up and cannot be moved, and that the winching function has been stopped.

[0029] Figure 3 is a flowchart showing an exemplary method according to another embodiment of the present disclosure. When the controller determines that winching should begin via operator control 1, drive motor 3 may be powered to provide torque and speed to winch spool 5. In this way, the rope 6 is spooled or unspooled onto or off winch spool 5, thereby pulling or releasing load 7. This represents the beginning of the flowchart of Figure 3. At the beginning of the flowchart of Figure 3, indicators 14, 13, 12, 11 may be initialized (e.g., turned off if not already off).

[0030] At process block 15, the voltage at voltage sensor 9 may be continuously read in, the torque the motor is producing may be calculated, and may, together with the speed signal provided by encoder 4, be used to calculate the speed of winch spool 5.

[0031] At decision block 16, the torque and speed may be compared to pre-determined values to determine if the winch is operating normally. If the condition is true and the winch is operating normally, process block 17 may turn on indicator 14 (green) and return to process block 15 to permit continued operation. If the condition is false, indicating that the winch may not be operating normally, control may pass to decision block 18.

[0032] At decision block 18, the torque and speed may be compared to pre-determined values to determine if the winch is operating outside of its normal range such that, if left uninhibited, could resulted in overheating drive motor 3. If the condition is true, process block 19 may turn off indicator 14 (green) and turn on indicator 13 (yellow), and then return to process block 15. If the condition is false, control may pass to decision block 20.

[0033] At decision block 20, the torque and speed may be compared to pre-determined values to determine if the winch is operating outside of a safe range such that, if left uninhibited, could damage the winch or rupture the rope. If the condition is true, process block 21 will turn off indicator 14 (green) and indicator 13 (yellow) and turn on indicator 12 (orange), stop drive motor 3, and exit the process. If the condition is false, control may pass to decision block 22.

[0034] At decision block 22, the torque may be compared to a value equivalent to a stall (/.< ., the speed equals 0), to determine if the winch rope is bound, or if the load is at the winch’s fairlead in a winching in scenario. If the condition is true, process block 23 may turn off indicators 14 (green), 13 (yellow), and 12 (orange), turn on indicator 11 (red), stop drive motor 3, and exit the process. If the condition is false, control may pass to process block 15. [0035] If controller and software 2 determines drive motor 3 has been turned off, for example by process blocks 21 or 23, or by an operator using operator control 1, the process routine described in the flowchart may exit.

[0036] With reference to Figure 4, the present disclosure may be embodied as a method 100 of controlling a winch. The method may include receiving 103 a speed signal corresponding to a speed of a motor of a winch. A current signal may be received 106, the current signal corresponding to a current of the motor. For example, the current signal may be a voltage measured across a current sense circuit, such as, for example, a current sense resistor, etc. The method includes determining 109 if the winch is operating within one or more predetermined parameter based on the received speed signal and received current signal. The method 100 may include calculating 112 a motor torque based on the current signal; and calculating 115 a speed of a spool of the winch based on the speed signal.

[0037] A normal operation signal may be provided 118 when the winch is operating within the pre-determined parameters.

[0038] The method may further include determining 121 if the winch is operating in a condition for overheating risk based on the received speed signal and the received current signal. For example, an overheating risk may be determined where the winch is operating out of its normal range (e.g., speed and/or torque exceeds ratings, etc.) The method may further include receiving one or more temperature signals from one or more thermocouples. An overheating risk signal may be provided 124 when an overheating risk condition is determined. The method may include providing 127 reduced power signal to the motor. For example, where the method is performed by a controller, the controller may provide a reduced power signal to the motor and/or may provide a signal to reduce power to the motor.

[0039] The method may further include determining 130 if the winch is operating in a stall condition based on the received speed signal and the received current signal. For example, where the speed signal is 0 or near 0, etc. A stall signal may be provided 133 when an stall condition is determined. The motor may be stopped 136. For example, where the method is performed by a controller, the controller may stop providing a power signal to the motor and/or may provide a signal to stop the motor. [0040] The method may further include determining 139 if the winch is operating in a condition for winch or rope damage risk based on the received speed signal and the received current signal. For example, where the load is determined to exceed a rated load of the winch or rope, etc. A damage risk signal may be provided 142 when an winch or rope damage risk condition is determined. The motor may be stopped 145. For example, where the method is performed by a controller, the controller may stop providing a power signal to the motor and/or may provide a signal to stop the motor.

[0041] The controller may be implemented in practice by any combination of hardware, software, and firmware. In addition, its functions as described herein may be performed by one unit, or divided up among different components, each of which may be implemented in turn by any combination of hardware, software, and firmware. Program code or instructions for the controller to implement various methods and functions may be stored in readable storage media, such as a memory in the electronic data storage unit or other memory.

[0042] The controller may be configured to perform a number of functions using the output of the system or other output. For instance, the controller may be configured to send the output to an electronic data storage unit or another storage medium. The controller may be further configured as described herein.

[0043] The controller may be in communication with and/or include a memory. The memory can be, for example, a Random-Access Memory (RAM) (e.g., a dynamic RAM, a static RAM), a flash memory, a removable memory, and/or so forth. In some instances, instructions associated with performing the operations described herein (c.g, the process depicted in Figures 3 or 4) can be stored within the memory and/or a storage medium (which, in some embodiments, includes a database in which the instructions are stored) and the instructions are executed at the controller.

[0044] In some instances, the controller includes one or more modules and/or components. Each module/component executed by the controller can be any combination of hardware-based module/component (e.g., a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), a digital signal processor (DSP)), software-based module (e.g., a module of computer code stored in the memory and/or in the database, and/or executed at the processor), and/or a combination of hardware- and software-based modules. Each module/component executed by the controller is capable of performing one or more specific functions/operations as described herein. In some instances, the modules/components included and executed in the controller can be, for example, a process, application, virtual machine, and/or some other hardware or software module/component. The controller can be any suitable controller configured to run and/or execute those modules/components. The controller can be any suitable processing device configured to run and/or execute a set of instructions or code. For example, the controller can be a general purpose processor, a central processing unit (CPU), an accelerated processing unit (APU), a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), a digital signal processor (DSP), and/or the like.

[0045] By using an intelligent controller disclosed herein, it has been shown that a winching function can be made smarter and safer by detecting torque and speed values for the winch spool and determining if those values should limit or stop winch function. This intelligent controller may also be used to determine if the load is at the fairlead or if the rope is bound so that the winching function can be stopped. If the load is at the fairlead, there may no longer be a requirement to physically separate a magnet and reed switch, if equipped, to regain operator control and winch functionality.

[0046] Although the present disclosure has been described with respect to one or more particular embodiments, it will be understood that other embodiments of the present disclosure may be made without departing from the spirit and scope of the present disclosure.

Claims

What is claimed is:

1. A controller for closed-loop control of a winch, the controller comprising: a speed input configured to receive a speed signal corresponding to a speed of a motor of a winch; a current sense input configured to receive a signal corresponding to a current of the motor; and wherein the controller is configured to: sample a speed signal from the speed input; sample a current signal from the current sense input; and determine if the winch is operating within pre-determined parameters based on the sampled speed signal and the sampled current signal.

2. The controller of claim 1, wherein the controller is further configured to calculate a motor torque based on the current signal and to calculate a spool speed based on the speed signal.

3. The controller of claim 1, wherein the controller is further configured to provide a normal operation signal when the winch is operating within the pre-determined parameters.

4. The controller of claim 1, wherein the controller is further configured to determine if the winch is operating in a condition for overheating risk based on the sampled speed signal and the sampled current signal.

5. The controller of claim 1, wherein the controller is further configured to determine if the winch is operating in a stall condition based on the sampled speed signal and the sampled current signal.

6. The controller of claim 1, wherein the controller is further configured to determine if the winch is operating at condition for winch damage or rope damage based on the sampled speed signal and the sampled current signal.

7. The controller of claim 1, wherein the controller is further configured to provide one or more status signals when the winch is operating at risk for overheating, in a stall condition, or when operating at risk for winch or rope damage.

8. A winch comprising a controller according to any one of claims 1-8.

9. A method of controlling a winch, comprising: receiving a speed signal corresponding to a speed of a motor of a winch; receiving a current signal corresponding to a current of the motor; and determining if the winch is operating within pre-determined parameters based on the received speed signal and received current signal.

10. The method of claim 9, wherein the current signal is a voltage across a current sense circuit.

11. The method of claim 9, further comprising: calculating a motor torque based on the current signal; and calculating a speed of a spool of the winch based on the speed signal.

12. The method of claim 9, further comprising providing a normal operation signal when the winch is operating within the pre-determined parameters.

13. The method of claim 9, further comprising determining if the winch is operating in a condition for overheating risk based on the received speed signal and the received current signal.

14. The method of claim 9, further comprising determining if the winch is operating in a stall condition based on the received speed signal and the received current signal.

15. The method of claim 9, further comprising determining if the winch is operating at condition for winch damage or rope damage based on the received speed signal and the received current signal.