Motor control for gas engine exchange device

Abstract

Solves the problems of conventional technology. [Solution] The gas engine exchange device includes a housing, a battery receptacle coupled to the housing and receiving a battery pack, a motor inside the housing, a power take-off shaft that receives torque from the motor and protrudes from the side of the housing, a power switching network configured to supply power from the battery pack to the motor, and an electronic processor coupled to the power switching network and configured to control the power switching network to rotate the motor, the electronic processor configured to receive a command speed, determine whether the command speed is within an exclusion zone, set the output speed to the command speed depending on whether the command speed is outside the exclusion zone, set the output speed to a speed outside the exclusion zone depending on whether the command speed is within the exclusion zone, and control the power switching network to rotate the motor according to the output speed.

Description

【Technical Field】 【0001】 (Cross - reference to related applications) This application claims the benefit of U.S. Provisional Patent Application No. 62 / 932,711, filed on November 8, 2019, and U.S. Provisional Patent Application No. 63 / 009,642, filed on April 14, 2020, and incorporates by reference in its entirety the content of each of them herein. 【0002】 (Technical Field) This application relates to a motor unit for gas engine replacement, and more particularly to a motor unit for gas engine replacement for use with power equipment. 【Background Art】 【0003】 A small single - cylinder or multi - cylinder gasoline engine can be attached to power equipment and the equipment can be driven by a power take - off shaft. 【Summary of the Invention】 【Means for Solving the Problems】 【0004】 In some embodiments, the gas engine exchange device is provided comprising a housing; a battery receptacle coupled to the housing and configured to removably receive a battery pack; a motor located inside the housing; a power take-off shaft receiving torque from the motor and protruding from the side of the housing; a power switching network configured to selectively supply power from the battery pack to the motor; and an electronic processor. The electronic processor is coupled to the power switching network and configured to control the power switching network to rotate the motor. The electronic processor is configured to receive a command speed for the motor, determine whether the command speed is within an exclusion zone, set the output speed for the motor to the command speed depending on whether the command speed is outside the exclusion zone, set the output speed depending on whether the command speed is within the exclusion zone, and control the power switching network to rotate the motor according to the output speed set based on whether the command speed has been determined to be within an exclusion zone. 【0005】 In some embodiments, the electronic processor is configured to set the output speed to the upper limit of the exclusion zone depending on whether the previous output speed is greater than the exclusion zone. In some embodiments, the electronic processor is configured to set the output speed to the lower limit of the exclusion zone depending on whether the previous output speed is less than the exclusion zone. In some embodiments, the exclusion zone defines hysteresis around the resonant frequency of the mechanical system coupled to the motor. In some embodiments, the gas engine exchange device includes a vibration sensor, and the electronic processor is configured to identify the resonant frequency based on the output of the vibration sensor. In some embodiments, the gas engine exchange device includes a vibration sensor, and the electronic processor is configured to generate the exclusion zone based on the output of the vibration sensor. 【0006】 In some embodiments, a gas engine exchange device is provided comprising a housing, a vibration sensor, a battery receptacle coupled to the housing and configured to removably receive a battery pack, a motor located inside the housing, a power take-off shaft receiving torque from the motor and protruding from the side of the housing, a power switching network configured to selectively supply power from the battery pack to the motor, and an electronic processor. The electronic processor is coupled to the power switching network and configured to control the power switching network to rotate the motor. The electronic processor is configured to generate an exclusion zone based on the output of the vibration sensor, receive a command speed for the motor, determine an output speed for the motor based on the command speed and limit the operating speed to a value outside the exclusion zone, and control the power switching network to rotate the motor according to the determined output speed. 【0007】 In some embodiments, the electronic processor is configured to set the output speed to the upper limit of the exclusion zone depending on whether the previous output speed is greater than the exclusion zone. In some embodiments, the electronic processor is configured to set the output speed to the lower limit of the exclusion zone depending on whether the previous output speed is less than the exclusion zone. In some embodiments, the exclusion zone defines a hysteresis around the resonant frequency of the mechanical system coupled to the motor. In some embodiments, the gas engine exchanger includes a vibration sensor, and the electronic processor is configured to identify a resonant frequency based on the output of the vibration sensor, and the exclusion zone is generated based on the identified resonant frequency. 【0008】 In some embodiments, the system is provided comprising a pump and a gas engine exchange device. The gas engine exchange device comprises a housing, a battery receptacle coupled to the housing and configured to removably receive a battery pack, a motor located inside the housing, a power take-off shaft receiving torque from the motor, protruding from the side of the housing and coupled to the pump, a power switching network configured to selectively supply power from the battery pack to the motor, and an electronic processor. The electronic processor is coupled to the power switching network and configured to control the power switching network to rotate the motor. The electronic processor is also configured to receive a command speed for the motor, determine whether the command speed is within an exclusion zone, set the output speed for the motor to the command speed depending on whether the command speed is outside the exclusion zone, set the output speed depending on whether the command speed is within the exclusion zone, and control the power switching network to rotate the motor according to the output speed set based on whether the command speed has been determined to be within an exclusion zone. 【0009】 In some embodiments, the electronic processor is configured to set the output speed to the upper limit of the exclusion zone depending on whether the previous output speed is greater than the exclusion zone. In some embodiments, the electronic processor is configured to set the output speed to the lower limit of the exclusion zone depending on whether the previous output speed is less than the exclusion zone. In some embodiments, the exclusion zone defines a hysteresis around the resonant frequency of the mechanical system coupled to the motor. In some embodiments, the gas engine exchanger includes a vibration sensor, and the electronic processor is configured to identify a resonant frequency based on the output of the vibration sensor, and the exclusion zone is generated based on the identified resonant frequency. 【0010】 In some embodiments, the method is provided, comprising receiving a command speed for a motor by an electronic processor of a gas engine exchange unit. The method further comprises determining, by the electronic processor, whether the command speed is within an exclusion zone. The electronic processor further comprises setting the output speed for the motor to the command speed depending on whether the command speed is outside the exclusion zone, and setting the output speed to a speed outside the exclusion zone depending on whether the command speed is within the exclusion zone. The method further comprises controlling the power switching network by the electronic processor to rotate the motor of the gas engine exchange unit according to the output speed set based on whether the command speed has been determined to be within an exclusion zone. 【0011】 In some embodiments of the method, the electronic processor sets the output speed to the upper limit of the exclusion zone depending on whether the previous output speed is greater than the exclusion zone. In some embodiments of the method, the electronic processor sets the output speed to the lower limit of the exclusion zone depending on whether the previous output speed is less than the exclusion zone. In some embodiments of the method, the exclusion zone defines hysteresis around the resonant frequency of the mechanical system coupled to the motor. In some embodiments of the method, the gas engine exchange device includes a vibration sensor, and the electronic processor identifies the resonant frequency based on the output of the vibration sensor. In some embodiments, the gas engine exchange device includes a vibration sensor, and the electronic processor generates the exclusion zone based on the output of the vibration sensor. 【0012】 In some embodiments, the gas engine exchange device is provided comprising a housing; a battery receptacle coupled to the housing and configured to removably receive a battery pack; a motor located inside the housing; a power take-off shaft receiving torque from the motor and protruding from the side of the housing; a power switching network configured to selectively supply power from the battery pack to the motor; and an electronic processor. The electronic processor is coupled to the power switching network and configured to control the power switching network to rotate the motor. The electronic processor is configured to receive a command speed for the motor, generate an output speed for the motor based on the command speed, detect runaway conditions, and mitigate runaway conditions. 【0013】 In several embodiments, methods are provided for operating a gas engine exchange device, the gas engine exchange device comprising a housing; a battery receptacle coupled to the housing and configured to removably receive a battery pack; a motor located inside the housing; a power take-off shaft receiving torque from the motor and protruding from the side of the housing; a power switching network configured to selectively supply power from the battery pack to the motor; and an electronic processor. The electronic processor is coupled to the power switching network and configured to control the power switching network to rotate the motor. The method comprises the gas engine exchange device receiving a command speed for the motor, generating an output speed for the motor based on the command speed, detecting a runaway condition, and mitigating the runaway condition. 【0014】 In some embodiments, the gas engine exchange device is provided comprising a housing; a battery receptacle coupled to the housing and configured to removably receive a battery pack; a motor located inside the housing; a power take-off shaft receiving torque from the motor and protruding from the side of the housing; a power switching network configured to selectively supply power from the battery pack to the motor; and an electronic processor. The electronic processor is coupled to the power switching network and configured to control the power switching network to rotate the motor. The electronic processor is configured to monitor the motor current, estimate the load condition based on the motor current, and set the motor command speed based on the load condition. 【0015】 In several embodiments, methods are provided for operating a gas engine exchange device, the gas engine exchange device comprising a housing; a battery receptacle coupled to the housing and configured to removably receive a battery pack; a motor located inside the housing; a power take-off shaft receiving torque from the motor and protruding from the side of the housing; a power switching network configured to selectively supply power from the battery pack to the motor; and an electronic processor. The electronic processor is coupled to the power switching network and configured to control the power switching network to rotate the motor. The method comprises the gas engine exchange device monitoring the motor current, estimating a load condition based on the motor current, and setting a motor command speed based on the load condition. 【0016】 In some embodiments, the gas engine exchange device is provided comprising a housing; a battery receptacle coupled to the housing and configured to removably receive a battery pack; a motor located inside the housing; a power take-off shaft receiving torque from the motor and protruding from the side of the housing; a power switching network configured to selectively supply power from the battery pack to the motor; and an electronic processor. The electronic processor is coupled to the power switching network and configured to control the power switching network to rotate the motor. The electronic processor is configured to receive position control commands, determine the loading position, and control the motor based on the loading position. 【0017】 In several embodiments, methods are provided for operating a gas engine exchange device, the gas engine exchange device comprising a housing; a battery receptacle coupled to the housing and configured to removably receive a battery pack; a motor located inside the housing; a power take-off shaft receiving torque from the motor and protruding from the side of the housing; a power switching network configured to selectively supply power from the battery pack to the motor; and an electronic processor. The electronic processor is coupled to the power switching network and configured to control the power switching network to rotate the motor. The method comprises the gas engine exchange device receiving a position control command, determining a loading position, and controlling the motor based on the loading position. 【0018】 Before describing any embodiment in detail, it should be understood that the embodiments are not limited in their intended use to the structural and arrangement details of the components described in the following description or shown in the following drawings. The embodiments described herein can be implemented or performed in a variety of ways. It should also be understood that the expressions and terms used herein are for illustrative purposes only and should not be considered limiting. The use of “including,” “comprising,” or “having,” and their variations herein, means to include the items listed thereafter, their equivalents, and additional items. The terms “attached,” “connected,” and “joined” are used broadly and include both direct and indirect attachment, connection, and joining. Furthermore, “connected” and “joined” are not limited to physical or mechanical connection or joining, but may include electrical connection or joining, whether direct or indirect. In addition, as used herein with the list of items, “and / or” means that the items may be taken together, as a subset, or as alternatives (for example, “A, B, and / or C” means A; B; C; A and B; B and C; A and C; or A, B, and C). 【0019】 It should be noted that multiple hardware and software-based devices, as well as multiple different structural components, may be used to implement the embodiments described herein. Furthermore, as will be described in the following paragraphs, the specific configurations shown in the drawings are intended as illustrative embodiments, and other alternative configurations are possible. The terms “processor,” “central processing unit,” and “CPU” are interchangeable unless otherwise specified. When the terms “processor,” “central processing unit,” or “CPU” are used to identify a unit that performs a particular function, it should be understood that, unless otherwise specified, those functions may be performed by a single processor or by multiple processors arranged in any form, including parallel processors, serial processors, tandem processors, or cloud processing / cloud computing configurations. 【0020】 In addition, embodiments may include hardware, software, and electronic components or modules, and it should be understood that for the purposes of discussion, these may be illustrated and described as if most of the components were implemented only in hardware. However, those skilled in the art will recognize that based on reading this detailed description, in at least one embodiment, an electronic-based aspect may be implemented in software (e.g., stored on a non-transitory computer-readable medium) executable by one or more processing units such as a microprocessor and / or an application-specific integrated circuit ("ASIC"). For this reason, note that multiple hardware and software-based devices, as well as multiple different structural components, may be utilized to implement embodiments. 【0021】 Other features and aspects will become apparent upon consideration of the following detailed description and the accompanying drawings. 【Brief Description of the Drawings】 【0022】 [Figure 1] It is a perspective view of a gas engine replacement device according to an embodiment. [Figure 2] It is a plan view of the gas engine replacement device of FIG. 1. [Figure 3] It is a schematic view of the gas engine replacement device of FIG. 1. [Figure 4] It is a perspective view of the battery pack of the gas engine replacement device of FIG. 1. [Figure 5] It is a cross-sectional view of the battery pack of FIG. 4. [Figure 6] It is a cross-sectional view of the battery receptacle of the gas engine replacement device of FIG. 1. [Figure 7] It is a cross-sectional view of the motor of the gas engine replacement device of FIG. 1. [Figure 8] It is a schematic view of the motor, gear train, and power take-off shaft of the gas engine replacement device of FIG. 1. [Figure 9] It is a block diagram of the gas engine replacement device of FIG. 1. [Figure 10] Schematic diagram of a power switching network for driving the motor of the gas engine replacement device of FIG. 1. [Figure 11A] Diagram showing the operation of the power switching network of FIG. 10 during forward movement of the motor. [Figure 11B] Diagram showing the operation of the power switching network of FIG. 10 during reverse movement of the motor. [Figure 12] Schematic block diagram of the motor controller of the gas engine replacement device of FIG. 1. [Figure 13] Diagram showing the speed profile used by the motor controller of FIG. 12. [Figure 14] Flow diagram of an exemplary method for speed control of the motor of the gas engine replacement device of FIG. 1. [Figure 15] A pump system including the gas engine replacement device of FIG. 1 is shown. [Figure 16] Shows the speed-torque curve of the pump system. [Figure 17] Flow diagram of a method for runaway detection and control of the motor of the gas engine replacement device of FIG. 1. [Figure 18] Flow diagram of a method for load monitoring using the gas engine replacement device of FIG. 1. [Figure 19] Diagram showing disturbances in motor current useful for identifying the load state according to some embodiments. [Figure 20] Diagram showing disturbances in motor current useful for identifying the load state according to some embodiments. [Figure 21] A mixing system including the gas engine replacement device of FIG. 1 is shown. [Figure 22] A cutting system including the gas engine replacement device of FIG. 1 is shown. [Figure 23] Flow diagram of an exemplary method for load positioning using the gas engine replacement device of FIG. 1. [Figure 24]Figure 1 shows a cooling system for one or more electronic components in a gas engine exchange device. [Modes for carrying out the invention] 【0023】 As shown in Figures 1 and 2, the gas engine exchange device 10 for use with a part of the power equipment includes a housing 14 having a first side surface 18, a second side surface 22 adjacent to the first side surface 18, a third side surface 26 facing the second side surface 22, a fourth side surface 28 facing the first side surface 18, a fifth side surface 30 extending between the second and third side surfaces 22 and 26, and a sixth side surface 32 facing the fifth side surface 30. The gas engine exchange device 10 also includes a flange 34 coupled to the housing 14 at the first side surface 18, an electric motor 36 located inside the housing 14, and a power take-off shaft 38 protruding from the second side surface 22 and receiving torque from the motor 36. In some embodiments, as will be described in more detail below, the power take-off shaft 38 protrudes from the first side surface 18 and the flange 34. As shown in Figure 3, the gas engine exchange device 10 also includes control electronics 42, including wiring and a controller 46, which are located inside the housing 14 and electrically connected to the motor 36. A similar gas engine exchange device 10 is described and illustrated in U.S. Patent Application No. 16 / 551,197, filed August 26, 2019, which is incorporated herein by reference in its entirety. 【0024】 As shown in Figures 1-6, the gas engine exchange device 10 also includes a battery pack 50 that is removably received into a battery receptacle 54 within a housing 14 and transmits current from the battery pack 50 to the motor 36 via control electronics 42. Referring to Figures 4-6, the battery pack 50 includes a battery pack housing 58 having a support 62 and first terminals 66 electrically connected to a plurality of battery cells 68 supported by the pack housing 58. The support 62 provides a slide-on configuration having a projection / recess 70 that cooperates with a complementary projection / recess 74 (shown in Figure 6) of the battery receptacle 54. In the embodiments shown in Figures 4-6, the projection / recess 70 of the battery pack 50 is a guide rail, and the projection / recess 74 of the battery receptacle 54 is a guide recess. Similar battery packs are described and illustrated in U.S. Patent Application Publication No. 2019 / 0006980, filed July 2, 2018, and are incorporated herein by reference in their entirety. In some embodiments, the battery cells 68 have a nominal voltage of up to about 80V. In some embodiments, the battery cells 68 have a nominal voltage of up to about 120V. In some embodiments, the battery pack 50 has a weight of up to about 6 lb. In some embodiments, each of the battery cells 68 has a diameter of up to 21 mm and a length of up to about 71 mm. In some embodiments, the battery pack 50 contains up to 20 battery cells 68. In some embodiments, the battery cells 68 are connected in series. In some embodiments, the battery cells 68 are operable to output a sustained operating discharge current between about 40A and about 60A. In some embodiments, each of the battery cells 68 has a capacity between about 3.0Ah and about 5.0Ah. 【0025】 Figure 6 shows a battery receptacle 54 of a gas engine exchange device 10 according to several embodiments. The battery receptacle 54 includes a projection / recess 74, a second terminal 78, a latch mechanism 82, and a power cut-off switch 86. The projection / recess 74 cooperates with the projection / recess 70 of the battery pack 50 to mount the battery pack 50 onto the battery receptacle 54 of the gas engine exchange device 10. Once the battery pack 50 is mounted on the gas engine exchange device 10, the second terminal 78 and the first terminal 66 are electrically connected. The latch mechanism 82 protrudes from the surface of the battery receptacle 54 and is configured to engage with the battery pack 50 to maintain the engagement between the battery pack 50 and the battery receptacle 54. Thus, the battery pack 50 is connectable to and thereby supportable by the battery receptacle 54, so as to be supported by the housing 14 of the gas engine exchange device 10. In some embodiments, the battery pack receptacle 54 is positioned on the housing 14 at a location that creates the maximum possible separation distance between the motor 36 and the battery pack 50 in order to suppress vibrations transmitted from the motor 36 to the battery pack 50. In some embodiments, an elastomer member is positioned on the battery pack receptacle 54 in order to suppress vibrations transmitted from the motor 36 to the battery pack 50 through the housing 14. 【0026】 In other embodiments (not shown), the latch mechanism 82 may be positioned at various locations (e.g., the side wall, end wall, or top end wall of the battery receptacle 54) such that the latch mechanism 82 engages with a corresponding structure on the battery pack 50 to maintain engagement between the battery pack 50 and the battery receptacle 54. The latch mechanism 82 includes a pivotable actuator or handle 90 that operably engages with a latch member 94. The latch member 94 is slidably disposed within a bore 98 of the receptacle 54 and is biased toward the latch position by a biasing member 102 (e.g., a spring) to protrude through the surface of the battery receptacle 54 into the cavity within the battery pack 50. 【0027】 The latch mechanism 82 also includes a power disconnect switch 86 (e.g., a microswitch) that facilitates the electrical connection / disconnection of the battery pack 50 from the battery receptacle 54 while the handle 90 is operating to pull the latch member 94 out of the battery pack 50. The power disconnect switch 86 may act to electrically disconnect the battery pack 50 from the gas engine exchange device 10 before removing the battery pack 50 from the battery receptacle 54. The power disconnect switch 86 is activated when the latch member 94 moves from the latched position (i.e., when the latch member 94 is fully inside the cavity of the battery pack 50) to an intermediate position. The power disconnect switch 86 is electrically connected to the controller 46 and may generate an interrupt indicating that the battery pack 50 is disconnected from the gas engine exchange device 10. When the controller 46 receives the interrupt, the controller 46 initiates a power disconnect operation to safely disconnect the control electronics 42 of the gas engine exchange device 10. Similar latching mechanisms and disconnecting switches are described and illustrated in U.S. Patent Application Publication No. 2019 / 0006980 and are incorporated herein by reference. 【0028】 As shown in Figure 7, the motor 36 includes a motor housing 96 having an outer diameter 97, a stator 99 having a nominal outer diameter 103 with a maximum of approximately 80 mm, a rotor 104 having an output shaft 106 and supported to rotate inside the stator 99, and a fan 108. A similar motor is described and illustrated in U.S. Patent Application Publication No. 2019 / 0006980 and is incorporated herein by reference. In some embodiments, the motor 36 is a brushless DC motor. In some embodiments, the motor 36 has a power output of at least approximately 2760 W. In some embodiments, the power output of the motor 36 may drop to less than 2760 W during operation. In some embodiments, the fan 108 has a diameter 109 that is larger than the diameter 97 of the motor housing 96. In some embodiments, the motor 36 can be stopped by an electronic clutch (not shown) for rapid overload control. In some embodiments, the motor 36 has a maximum of approximately 443,619 mm 3 It has a volume of . In some embodiments, the motor has a maximum weight of approximately 4.6 lb. The housing 14 includes an inlet vent and an outlet vent so that the motor fan 108 draws air through the inlet vent along the control electronics 42 to cool the control electronics 42 before the air is discharged through the outlet vent. In the embodiment shown in Figure 7, the motor 36 is an internal rotor motor, but in other embodiments, the motor 36 can be an external rotor motor having a maximum nominal outer diameter (i.e., nominal outer diameter of the rotor) of approximately 80 mm. 【0029】 Referring to Figure 8, the motor 36 can transmit torque to the power take shaft 38 in various configurations. In some embodiments, the output shaft 106 is also the power take shaft 38, such that the motor 36 directly drives the power take shaft 38 without any intermediate gear train. For example, the motor 36 may be a direct-drive multi-pole motor. As shown in Figure 8, in other embodiments, the gas engine exchange device 10 includes a gear train 110 that transmits torque from the motor 36 to the power take shaft 38. In some embodiments, the gear train 110 may include a mechanical clutch (not shown) that interrupts the transmission of torque from the motor 36 to the power take shaft 38. In some embodiments, the gear train 110 may include a planetary transmission that transmits torque from the output shaft 106 to the power take shaft 38, and the axis of rotation of the output shaft 106 is coaxial with the axis of rotation of the power take shaft 38. In some embodiments, the gear train 110 includes spur gears that engage with the rotor's output shaft 106 such that the axis of rotation of the output shaft 106 is offset from and parallel to the axis of rotation of the power take-off shaft 38. In some embodiments, the gear train 110 includes bevel gears such that the axis of rotation of the output shaft 106 is perpendicular to the axis of rotation of the power take-off shaft 38. In other embodiments utilizing bevel gears, the axis of rotation of the output shaft 106 is not perpendicular, parallel, or coaxial with the axis of rotation of the power take-off shaft 38, and the power take-off shaft 38 protrudes from the flange 34. 【0030】 In some embodiments, the gas engine exchange device 10 includes an on / off indicator (not shown). In some embodiments, the gas engine exchange device 10 includes a filter (not shown) to prevent airborne debris from entering the motor 36 and control electronics 42. In some embodiments, the filter includes a fouling filter sensor (not shown) and a self-cleaning mechanism (not shown). In some embodiments, the motor 36 will mimic a gas engine response when encountering resistance such as deceleration or getting stuck in mud. In some embodiments, the gas engine exchange device 10 includes a heat sink 202 within the housing 14 for air-cooling the control electronics 42 (Figures 1 and 2). In some embodiments, the gas engine exchange device 10 is liquid-cooled. 【0031】 In some embodiments, the output shaft 106 of the rotor 104 has both forward and reverse capabilities, as will be further described below. In some embodiments, the forward and reverse capabilities are controllable without shifting the gears of the gear train 110, compared to a gas engine, which cannot achieve forward / reverse capabilities without extra gears and time delays. Thus, the gas engine exchange device 10 offers higher speed, lighter weight, and lower cost. The gas engine exchange device 10 also offers additional speed, weight, and cost advantages compared to a gas engine, as it has fewer moving parts and no combustion system. 【0032】 The gas engine exchange device 10 can operate in any orientation relative to the ground (vertical, horizontal, or upside down) for extended periods, offering advantages over four-stroke gas engines that can only operate for short periods in one orientation and slight incline. Because the gas engine exchange device 10 does not require gas, oil, or other fluids, it can be operated, transported, and stored upside down or on any given side without leakage or spillage. 【0033】 During operation, the gas engine system can be replaced using the gas engine replacement device 10. Specifically, the gas engine replacement device 10 can be attached to a part of a power equipment having a second bolt pattern by aligning a first bolt pattern defined by a plurality of apertures in the flange 34 with a second bolt pattern. In some embodiments, the flange 34 may include one or more intermediate mounting members or adapters positioned between the flange 34 itself and the flange of the part of the power equipment having the second bolt pattern, such that the adapter connects the flange 34 to the power equipment. In these embodiments, the adapter includes both the second and first bolt patterns such that the first bolt pattern of the flange 34 aligns with the first bolt pattern of the adapter, and the second bolt pattern of the adapter aligns with the second bolt pattern defined on the part of the power equipment, thereby enabling the flange 34 of the gas engine replacement device 10 to be connected to the part of the power equipment. 【0034】 Alternatively, the gas engine exchange device 10 can be connected to a part of the power equipment using a belt system by providing a belt that operably connects the power take-off shaft and the equipment bit. Thus, the power take-off shaft 38 of the gas engine exchange device 10 can be used to drive equipment. 【0035】 During operation, the housing 14 of the gas engine exchange unit 10 is considerably cooler than the housing of the internal combustion unit because there is no combustion in the gas engine exchange unit 10. Specifically, when the gas engine unit is in operation, the housing of the gas engine unit reaches over 220°C. In contrast, when the gas engine exchange unit 10 is in operation, the entire outer surface of the housing 14 is below 95°C. Tables 1 and 2 below further specifically list the temperature limits of various components on the housing 14 of the gas engine exchange unit 10. 【0036】 Table 1 below lists the Underwriter's Laboratories (UL) temperature limits for various components commonly used in power tools, depending on whether those components are made of metal, plastic, rubber, wood, porcelain, or glass. For example, in at least some embodiments, the rated temperature of plastic is never exceeded by the gas engine exchange device 10. 【0037】 [Table 1] 【0038】 Table 2 below lists the UL temperature limits for various components of the battery pack housing 58 of the battery pack 50, depending on whether those components are made of metal, plastic, or rubber. For example, in at least some embodiments, the rated temperature of the plastic is not exceeded by the gas engine exchange device 10. 【0039】 [Table 2] 【0040】 Figure 9 shows a simplified block diagram of a gas engine exchange device 10 according to an exemplary embodiment. As shown in Figure 9, the gas engine exchange device 10 includes an electronic processor 302, a memory 306, a battery pack 50, a power switching network 310, a motor 36, a rotor position sensor 314, a current sensor 318, a user input device 322 (e.g., throttle, trigger, or power button), a transceiver 326, an indicator 330 (e.g., a light-emitting diode), and a vibration sensor 320. In some embodiments, the gas engine exchange device 10 includes fewer or additional components than those shown in Figure 9. For example, the gas engine exchange device 10 may include a battery pack fuel gauge, work lights, additional sensors, a kill switch, a power cut-off switch 86, etc. In some embodiments, the elements of the gas engine exchange device 10 shown in Figure 9, which include one or more of the following: an electronic processor 302, a memory 306, a power switching network 310, a rotor position sensor 314, a current sensor 318, a user input device 322, a transceiver 326, an indicator 330, and a vibration sensor 320, form at least part of the control electronics 42 shown in Figure 3, and the electronic processor 302 and the memory 306 form at least part of the controller 46 shown in Figure 3. 【0041】 Memory 306 includes read-only memory (ROM), random access memory (RAM), other non-temporary computer-readable media, or a combination thereof. The electronic processor 302 is configured to communicate with memory 306 to store and retrieve stored data. The electronic processor 302 is configured to receive instructions and data from memory 306 and, in particular, to execute instructions. Specifically, the electronic processor 302 executes instructions stored in memory 306 to perform the methods described herein. 【0042】 As described above, in some embodiments, the battery pack 50 is detachably mounted to the housing of the gas engine exchange device 10 so that different battery packs 50 may be attached to and detached from the gas engine exchange device 10 to provide different amounts of power to the gas engine exchange device 10. Further descriptions of the battery pack 50 (e.g., nominal voltage, sustained discharge current, size, number of cells, operation, etc.) and the motor 36 (e.g., output, size, operation, etc.) are provided above with reference to Figures 1-8. 【0043】 The power switching network 310 allows the electronic processor 302 to control the operation of the motor 36. Generally, when the user input device 322 is pressed (or otherwise activated), current is supplied from the battery pack 50 to the motor 36 via the power switching network 310. When the user input device 322 is not pressed (or otherwise activated), no current is supplied from the battery pack 50 to the motor 36. In some embodiments, the amount by which the user input device 322 is pressed relates to or corresponds to a desired rotational speed of the motor 36. In other embodiments, the amount by which the user input device 322 is pressed relates to or corresponds to a desired torque. In other embodiments, a separate input device (e.g., a slider, dial, etc.) that communicates with the electronic processor 302 to provide a desired rotational speed or torque to the motor 36 is included in the gas engine exchange device 10. 【0044】 In response to the electronic processor 302 receiving a drive request signal from the user input device 322, the electronic processor 302 activates the power switching network 310 to supply power to the motor 36. Through the power switching network 310, the electronic processor 302 controls the amount of current available to the motor 36, thereby controlling the speed and torque output of the motor 36. The power switching network 310 may include a number of field-effect transistors (FETs), bipolar transistors, or other types of electrical switches. For example, the power switching network 310 may include a 6-FET bridge (see Figure 10) that receives a pulse-width modulation (PWM) signal from the electronic processor 302 to drive the motor 36. 【0045】 The rotor position sensor 314 and the current sensor 318 are coupled to the electronic processor 302 and transmit various control signals to the electronic processor 302 indicating different parameters of the gas engine exchange device 10 or the motor 36. In some embodiments, the rotor position sensor 314 includes one Hall sensor or multiple Hall sensors. In other embodiments, the rotor position sensor 314 includes a right-angle phase encoder mounted on the motor 36. The rotor position sensor 314 outputs motor feedback information to the electronic processor 302, such as an indicator (e.g., a pulse) when the magnets of the motor 36's rotor rotate across the surface of the Hall sensor. In yet another embodiment, the rotor position sensor 314 includes, for example, a voltage or current sensor that provides an indicator of the back electromotive force (inverse EMF) generated in the motor coil. The electronic processor 302 may determine the rotor position, rotor speed, and rotor acceleration based on the back EMF signal received from the rotor position sensor 314, i.e., the voltage or current sensor. The rotor position sensor 314 can be combined with the current sensor 318 to form a combined current and rotor position sensor. In this embodiment, the combined sensor provides current to the active phase coils of the motor 36 and also provides current to one or more inactive phase coils of the motor 36. The electronic processor 302 measures the current flowing to the motor based on the current flowing to the active phase coils and measures the motor speed based on the current in the inactive phase coils. 【0046】 Based on motor feedback information from the rotor position sensor 314, the electronic processor 302 can determine the rotor's position, velocity, and acceleration. In response to the motor feedback information and signals from the user input device 322, the electronic processor 302 transmits control signals to control the power switching network 310 and drive the motor 36. For example, by selectively enabling and disabling the FETs of the power switching network 310, power received from the battery pack 50 is periodically and selectively applied to the stator windings of the motor 36 to rotate the motor's rotor. The motor feedback information is used by the electronic processor 302 to ensure the proper timing of control signals to the power switching network 310 and, in some cases, to provide closed-loop feedback to control the motor 36's speed to a desired level. For example, in order to drive the motor 36, the electronic processor 302 uses motor positioning information from the rotor position sensor 314 to determine where the rotor magnet is located relative to the stator windings, and (a) energizes the next pair (or more pairs) of stator windings in a predetermined pattern to apply a magnetic force to the rotor magnet in the desired direction of rotation, and (b) demagnetizes the previously energized pair (or more pairs) of stator windings to prevent the application of a magnetic force to the rotor magnet opposite to the direction of rotation of the rotor. 【0047】 The current sensor 318 monitors or detects the current level of the motor 36 during the operation of the gas engine exchange device 10 and provides a control signal indicating the detected current level to the electronic processor 302. The electronic processor 302 may use the detected current level to control the power switching network 310, as will be described in more detail below. 【0048】 The transceiver 326 enables communication between the electronic processor 302 and an external device 338 (e.g., a smartphone, tablet, or laptop computer) via a wired or wireless network 334. In some embodiments, the transceiver 326 may comprise separate transmitting and receiving components. In some embodiments, the transceiver 326 may comprise a wireless adapter attached to the gas engine exchange device 10. In some embodiments, the transceiver 326 is a wireless transceiver that encodes information received from the electronic processor 302 into a carrier radio signal and transmits the encoded radio signal to the external device 338 via the communication network 334. The transceiver 326 also decodes information from the radio signal received from the external device 338 via the communication network 334 and provides the decoded information to the electronic processor 302. In some embodiments, the transceiver 326 communicates with one or more external sensors 340 via the communication network 334. For example, the external sensors 340 may be associated with equipment to which the gas engine exchange device 10 is attached. In some embodiments, the external sensor 340 is a speed sensor, a position sensor, and the like. 【0049】 The communication network 334 provides wired or wireless connectivity between the gas engine exchange device 10, the external device 338, and the external sensor 340. The communication network 334 may include a short-range network, such as a Bluetooth® network or a Wi-Fi network, or a long-range network, such as the Internet or a cellular network. 【0050】 As shown in Figure 9, the indicator 330 is also coupled to the electronic processor 302 and receives control signals from the electronic processor 302 to turn on and off or otherwise transmit information based on different states of the gas engine exchange unit 10. The indicator 330 includes, for example, one or more light-emitting diodes ("LEDs") or a display screen. The indicator 330 may be configured to display the state of the gas engine exchange unit 10 or information related thereto. For example, the indicator 330 may be configured to show the measured electrical characteristics of the gas engine exchange unit 10, the state of the gas engine exchange unit 10, the mode of the gas engine exchange unit 10, etc. The indicator 330 may also include elements that transmit information to the user via audible or tactile output. In some embodiments, the indicator 330 includes an eco-indicator that shows the amount of energy being used by the load during operation. 【0051】 The connections between the components of the gas engine exchange unit 10 are simplified in Figure 9. In reality, the wiring of the gas engine exchange unit 10 is more complex, as its components are interconnected by several wires for power and control signals. For example, each FET in the power switching network 310 is separately connected to the electronic processor 302 by a control line, each FET in the power switching network 310 is connected to the terminals of the motor 36, and the power line from the battery pack 50 to the power switching network 310 includes a positive wire and a negative / ground wire, etc. In addition, the power lines may have a larger gauge / diameter to handle increased currents. Furthermore, although not shown, additional control and power lines are used to interconnect additional components of the gas engine exchange unit 10. 【0052】 Figure 10 shows an embodiment of a power switching network 310 for driving the motor 36 of the gas engine exchange device 10. The power switching network 310 includes three high-side FETs H1, H2, and H3 and three low-side FETs L1, L2, and L3, each having a first, i.e., conducting state and a second, i.e., non-conducting state. The power switching network 210 is used to selectively apply power from the battery pack 50 to the motor 36. An exemplary method by which the high-side and low-side switches are controlled to operate the motor 36 in the forward and reverse directions is described below. 【0053】 The high-side and low-side switches may be controlled using (pulse-width modulated) PWM commutation, centerline commutation, or other commutation methods. Figure 11A shows a simple PWM commutation that controls the motor 36 to rotate in the forward direction. As shown in Figure 11A, each of the high-side FETs H1, H2, and H3 conducts periodically throughout the entire commutation phase. When one of the FETs H1, H2, and H3 stops conducting, the next high-side FET begins conducting. Similarly, each of the low-side FETs L1, L2, and L3 conducts periodically throughout the entire commutation phase. When one of the FETs L1, L2, and L3 stops conducting, the next low-side FET begins conducting. However, one or both of the high-side or low-side FETs may be operated only for the duration of the commutation phase (e.g., by a PWM signal with a duty cycle of 75%, 50%, 25%, or another duty cycle) based on the desired speed of the motor 36 or the load on the motor 36. In the illustrated embodiment, the high-side and low-side FETs operate in predetermined pairs and in predetermined sequences to drive the motor 36 in the forward direction. In the embodiment shown in Figure 11A, H1 and L2 operate first, then H2 and L3 operate, then H3 and L1 operate. This sequence continues for the duration of the motor 36's operation in forward motion. Figure 11B shows a simple PWM commutation that controls the motor 36 to rotate in the reverse direction. In the embodiment shown in Figure 11B, H1 and L3 operate first, then H3 and L2 operate, then H2 and L1 operate. This sequence continues for the duration of the motor 36's operation in reverse motion. In some embodiments, one or more variations of the sequence can be made based on the desired motor operation. For example, one or both of the high-side and low-side FETs may be switched at a certain frequency during their operating phase to control the motor speed. In addition, the operating phases of the high-side and low-side FETs may be shifted to create overlap with other operations to achieve different control (e.g., field-oriented control). 【0054】 Figure 12 is a schematic block diagram of a motor controller 400, which in some embodiments is implemented by software stored in memory 306 and executed by an electronic processor 302. The motor controller 400 includes a profile generator 405, a speed controller 410, a torque controller 415, a brushless controller 420, and a D / DT unit 425. In some embodiments, the D / DT unit 425 calculates the derivative of the shaft angle to determine the shaft speed. The profile generator 405 receives throttle settings (e.g., from a user input device 322) and system settings. The profile generator 405 generates a speed reference for the speed controller 410 and a torque reference for the torque controller 415. The profile generator 405 aligns the speed and torque control with specific characteristics of the mechanical system coupled to the motor 36. 【0055】 The torque controller 415 receives shaft angle feedback from the rotor position sensor 314, and the speed controller 410 receives shaft speed feedback from the D / DT unit 425. The brushless controller 420 receives the speed and torque outputs from the speed controller 410 and the torque controller 415 and generates control signals for the power switching network 310 as described above. For example, the brushless controller 420 may drive the motor 36 by generating a sequence of PWM signals for each of the power switching elements of the power switching network 310. The motor controller 400 provides independent speed and torque control over a wide operating range. The motor controller 400 enables operation over a wide speed range that exceeds the typical speed range of an internal combustion engine. For example, while a reciprocating engine is limited to a small operating speed and torque transmission range, the motor controller 400 provides a virtually unlimited speed range with full torque control over that range without requiring the complex gearbox or reduction gear that is common in systems driven by internal combustion engines. The motor controller 400 can generate rated torque at or slightly above stall speed, thus supporting low-speed operation for jog and inching applications. 【0056】 The profile generator 405 enables the use of a speed profile that matches the mechanical system, thereby enabling features such as detection of pump cavitation or water hammer in pumping applications, nonlinear speed and torque relationships for fans and pumps, and torque limiting and control for lifting and tension winding applications. In some embodiments, to mitigate damage to the mechanical system, the motor controller 400 detects stall or lock conditions and limits the torque output by the torque controller 415. The motor controller 400 enables smoother acceleration and closed-loop speed regulation compared to mechanical systems operated by internal combustion engines that require inaccurate mechanical governors. The motor controller 400 provides load-independent speed control, thereby enabling constant-speed operation under load (e.g., for cutting or finishing applications). In some embodiments, the profile generator 405 receives shaft speed, shaft angle, or both. 【0057】 Referring to Figures 13 and 14, the motor controller 400 employs skip speed technology to avoid mechanical resonance inherent in the mechanical system coupled to the motor 36. Figure 13 is a diagram showing speed profiles used by the profile generator 405 in several embodiments. Figure 14 is a flowchart of an exemplary method for speed control of the motor 36. 【0058】 Mechanical systems often have rotational speeds associated with the system's natural resonant frequency. Operation at these speeds can cause excessive wear and failure of the mechanical system. In typical internal combustion engine applications, vibration dampers or other methods may be used to prevent damage from mechanical vibration. In some embodiments, the motor controller 400 is programmed to avoid speeds that cause mechanical resonance, thereby reducing the need for vibration damping equipment. The profile generator 405 provides speed profiles that avoid a predetermined programmed speed range. In one embodiment, the profile generator 405 provides speed commands with hysteresis. 【0059】 The profile generator 405 receives the command speed (specified, for example, by the throttle setting or system setting) and generates an output speed for the speed controller 410. As shown in Figure 13, the command speed and output speed follow the command speed until it approaches the skip speed. An exclusion zone 455 is defined in correspondence with a programmed speed range (for example, a skip speed or resonant frequency boundary defined for the mechanical system). For example, the exclusion zone 455 is defined by an upper speed limit 460 and a lower speed limit 465. Even if the command speed continues to increase, the profile generator 405 maintains the output speed at a first (low) speed value 470 until the command speed exceeds the upper limit 460 of the exclusion zone 455. The first (low) speed value 470 is the speed value associated with the command speed at the lower speed limit 465. After the command speed exceeds the exclusion zone 455, the output speed increases to match the command speed. The profile generator 405 implements the exclusion zone for both increasing and decreasing command speeds. For example, if the command speed decreases to or below the upper limit of 460, the profile generator 405 maintains the output speed at a second (high) speed value 475 until the command speed decreases to below the lower limit of 465 in the exclusion zone 455. The second (high) speed value 470 is the speed value associated with the command speed at the upper speed limit of 460. After the command speed decreases to below the exclusion zone 455, the output speed decreases to match the command speed. In some embodiments, multiple exclusion zones may be implemented by the profile generator 405. 【0060】 In some embodiments, the exclusion zone 455 is pre-programmed in the profile generator 405. For example, the upper and lower limits of the exclusion zone may be determined based on vibration testing of a particular mechanical system, including the gas engine exchange device 10, and limits stored in memory 306. In other embodiments, the profile generator 405 employs a vibration sensor 320 (see Figure 9) to measure vibrations of the mechanical system. In some embodiments, the profile generator 405 employs the exclusion zone 455 in response to the output of the vibration sensor 320 exceeding the vibration limits. In some embodiments, the profile generator 405 employs a learning technique to dynamically set the exclusion zone 455 as data on the vibration characteristics of the mechanical system is collected by the vibration sensor 320 over a period of time. 【0061】 In some embodiments, the profile generator 405 dynamically identifies exclusion zones 455 based on the real-time output of the vibration sensor 320. If the vibration sensor 320 measures vibrations exceeding a first threshold, the profile generator 405 limits the output speed to a first value, thereby setting a first limit for exclusion zones 455 (i.e., an upper limit if the command speed is decreasing, or a lower limit if the command speed is increasing). As the command speed continues to change, the profile generator 405 sets the output speed to a provisional command speed and determines whether the vibration sensor 320 measures vibrations below the first threshold. If the vibration level does not fall below the first threshold at the provisional command speed, the profile generator 405 determines that the gas engine exchange unit 10 is still in exclusion zones 455 and returns the output speed to the first value. If the vibration level falls below the first threshold at the provisional command speed, the profile generator 405 determines that a second limit for exclusion zones has been exceeded and allows continued operation at the provisional command speed. In some embodiments, the profile generator 405 sets a provisional command speed by a predetermined increment of the command speed change until it exceeds a second limit. 【0062】 As described above, the flow diagram 500 in Figure 14 is for a method of controlling the speed of the motor 36. The flow diagram 500 will be explained with respect to the motor controller 400 in Figure 12, which is mounted on the gas engine exchange device 10, and the exclusion zone as generally shown in Figure 13. However, in some embodiments, the method of the flow diagram 500 is implemented by other devices or modifications of the motor controller 400, and in some embodiments, the flow diagram is implemented with an exclusion zone that takes a different form than that shown in Figure 13. Referring to Figure 14, in block 505, the profile generator 405 receives a command speed for the motor 36 (e.g., indicated by a throttle setting or system setting, as previously described). For example, in some embodiments, the throttle setting and system setting are values ​​that represent a desired speed for the motor 36. 【0063】 In block 510, the profile generator 405 determines whether the command speed is within the exclusion zone (in block 510). For example, the profile generator 405 compares the command speed received in block 505 with the exclusion zone defined by the upper speed limit 460 and the lower speed limit 465. If, based on the comparison, the profile generator 405 determines that the command speed is greater than the lower speed limit 465 and less than the upper speed limit 460, the profile generator determines that the command speed is within the exclusion zone. Depending on whether the command speed is not within the exclusion zone, the profile generator 405 sets the output speed to the command speed (in block 515). 【0064】 In response to identifying that the command speed is within the exclusion zone, the profile generator 405 determines whether the previous output speed was lower than the exclusion zone (in block 520) (i.e., approaching from below). In response to identifying that the previous output speed was lower than the exclusion zone, the profile generator sets the command speed to a lower limit of 465, thereby setting the output speed to a first (low) speed 470 associated with the lower limit of 465 (in block 525). In other words, in block 525, the profile generator sets the output speed to the lower limit of the exclusion zone. If the previous output speed was not lower than the exclusion zone (i.e., approaching from above), the profile generator sets the command speed to an upper limit of 460, thereby setting the output speed to a second (high) speed 475 of the exclusion zone (in block 530). In other words, in block 530, the profile generator sets the output speed to the upper limit of the exclusion zone. 【0065】 The profile generator 405 receives the next command speed (in block 505) and repeats the speed limit until the command speed is no longer within the exclusion zone (in block 515). 【0066】 As described above, in some embodiments, the flow chart 500 is implemented with exclusion zones that take a different form than those shown in Figure 13. For example, in some embodiments, multiple exclusion zones are implemented, each having its own speed upper and lower limits, as well as first and second speeds associated with them. In such embodiments, in block 510, the profile generator 405 determines whether a command speed is in any of the exclusion zones, using a comparison function similar to that described above for determining whether a command speed is in an exclusion zone 455, although the constraints for the various exclusion zones are different. Furthermore, in blocks 525 and 530, the output speed is set to a first or second speed associated with the exclusion zone in which the command speed was identified, respectively. 【0067】 Figure 15 shows a pump system 620 including a frame 624 supporting the gas engine exchange device 10 and a pump 628, the gas engine exchange device 10 being operable to drive the pump 628. The illustrated pump 628 is a centrifugal pump having an impeller positioned inside the housing 632 of the pump 628, which is rotatable about an axis to move material from the inlet 636 of the pump 628 to the outlet 640 of the pump 628. In some embodiments, the gas engine exchange device 10 of the pump system 620 implements the motor control described above with respect to Figures 12-14. 【0068】 Figure 16 shows the speed-torque operating curve 700 of the pump system 620. The profile generator 405 within the motor controller 400 provides speed and torque control over the entire operating range, which closely matches the theoretical operating curve 705. 【0069】 Figure 17 is a flowchart 800 of an exemplary method for runaway detection and control of motor 36 according to several embodiments. The motor controller 400 employs runaway detection technology to identify and respond to potential runaway conditions. For example, in an embodiment in which the gas engine exchange device 10 provides power to move a vehicle such as a lawnmower, garden tractor, etc., the vehicle may be operated on a slope such that the vehicle speed increases when there is no signal to increase the motor command speed (e.g., using a user input device 322). The flowchart 800 is described with respect to the motor controller 400 of Figure 12 implemented in the gas engine exchange device 10. However, in some embodiments, the method of the flowchart 800 may be implemented by other devices or modifications of the motor controller 400. 【0070】 Referring to Figure 17, in block 805, the profile generator 405 of the motor controller 400 receives a command speed for the motor 36 (e.g., indicated by a throttle setting or system setting, as previously described). For example, in some embodiments, the throttle setting and system setting are values ​​representing a desired speed for the motor 36. In block 810, the motor controller 400 generates a command speed for the motor 36. For example, in some embodiments, the profile generator 405 generates the command speed based on the profile of the equipment powered by the gas engine exchange device 10, and the brushless controller 420 generates drive parameters for the motor 36 (e.g., a PWM duty cycle) based on the command speed. In some embodiments, the speed controller employs a closed-loop control process in which shaft speed feedback is employed to adjust the drive parameters employed by the brushless controller 420. In some embodiments, the speed controller employs an open-loop control process in which the drive parameters generated by the brushless controller 420 are set according to the throttle setting and system setting received by the profile generator 405 (e.g., via a fixed PWM duty cycle). 【0071】 The motor controller 400 detects a runaway condition in block 815. In some embodiments, the speed controller 410 monitors the shaft speed of the motor 36 or the power take-off shaft 140, etc., to identify a runaway condition. In one embodiment, the speed controller 410 identifies a runaway condition if the shaft speed increases by a predetermined value within a predetermined time interval. For example, the motor controller 400 may periodically detect the shaft speed (e.g., every 100 ms, 10 ms, or 1 ms) using the output from the rotor position sensor 314, and at the same frequency, detect the change in shaft speed relative to a previous reading (e.g., from 100 ms or 1 second ago). The motor controller 400 may further compare the change in shaft speed to a threshold, and identify a runaway condition if the detected change in shaft speed exceeds the threshold. Since the speed of the motor 36 is proportional to the speed of the vehicle powered by the gas engine exchange device 10, an unexpected increase in shaft speed indicates a runaway condition. In some embodiments, the speed controller 410 employs information from an external sensor 340 to identify a runaway condition. For example, the external sensor 340 may be a sensor that measures the ground speed of the vehicle powered by the gas engine exchanger 10. Rather than (or in addition to) determining whether the shaft speed increases by a predetermined value within a predetermined time interval, the motor controller determines whether the vehicle ground speed increases by a predetermined value within a predetermined time interval. This determination may be performed using a similar technique to that for the shaft speed, but instead using the sensed vehicle ground speed. In some embodiments, a threshold is set in part on a desired throttle setting, taking into account that the user requests a speed increase. For example, the threshold may be increased when the user requests a vehicle speed increase as indicated by the throttle setting signal, and decreased when the user requests a vehicle speed decrease as indicated by the throttle setting signal. In this way, common requests to increase the speed of the vehicle are less likely to be detected as a runaway condition. 【0072】 In response to the detection of a runaway condition, the motor controller 400 mitigates the runaway condition in block 820. In some embodiments, the motor controller 400 reduces the command speed in response to the detection of a runaway condition. In some embodiments, the motor controller 400 generates a braking signal in response to the detection of a runaway condition. In one embodiment, the motor controller 400 turns off the power switching network 310 by controlling all high-side and low-side FETs to turn off, allowing the motor 36 to coast and stop. Since the motor is no longer supplied with current when the FETs are turned off, the motor 36 stops due to friction or load acting on it. In other embodiments, passive or active braking may be used to stop the motor 36. During passive braking, the motor controller 400 may provide control signals to the high-side and low-side FETs to connect the motor to a braking load (e.g., a braking coil or braking resistor coupled between one or more stator coils and ground) to rapidly dissipate the energy in the motor 36 and brake the motor 36. During active braking, the motor controller 400 may control the motor coil to short-circuit to ground by turning off the high-side FET and turning on the low-side FET, thereby dissipating the remaining energy in the coil to ground. In another embodiment, the motor controller 400 may provide control signals to the high-side FET and low-side FET to perform regenerative braking and return the energy in the motor 36 to the battery pack 50 via the power switching network 310. In yet another embodiment, dynamic pulsing may be used to brake the motor 36. The motor controller 400 may provide control signals to the high-side FET and low-side FET to provide electric braking force to the rotor of the motor 36. The motor controller 400 may monitor the rotor position sensor 314 and activate the phase (i.e., the corresponding pair of high-side and low-side FETs) when the rotor is just passing through the phase. For example, the rotor position sensor 314 indicates that the rotor has just rotated past the phase corresponding to FETs H1 and L2.Accordingly, the motor controller 400 may activate FETs H1 and L2 to drive current through the stator coils and generate a magnetic field that provides a braking force to the rotor in the opposite direction to the rotor's rotation, thereby stopping its rotation. The motor controller 400 may continue to activate the FET pair at timings based on rotor position information from the rotor position sensor 314, in a sequence similar to that of Figure 11A, so that the resulting magnetic field generated by the coupled stator coils continues to provide a braking force that stops the rotation. In some embodiments, the motor controller 400 transmits a signal to the electronically controlled mechanical brake of the vehicle powered by the switching device 10. 【0073】 Referring to Figures 18, 19, and 20, the motor controller 400 employs load monitoring techniques to estimate the load state and adjust the load speed as a function of load parameters. Figure 18 is a flowchart of an exemplary method for load monitoring according to several embodiments. Figures 19 and 20 are diagrams showing disturbances in the motor current useful for identifying the load state according to several embodiments. For example, in an embodiment in which the gas engine exchanger 10 powers a cement mixer, the viscosity of the load is variable based on the contents of the mixer and the rotational speed. Increasing the rotational speed of the mixer generally decreases the viscosity, while decreasing the rotational speed of the mixer generally increases the viscosity. In another embodiment in which the gas engine exchanger 10 powers a cutting blade such as a lawnmower or saw, the density of the material being cut is variable (e.g., based on the length and thickness of the grass or the material composition). Increasing the rotational speed of the cutting blade is useful for thick grass or dense material, while decreasing the rotational speed of the cutting blade is useful for less dense grass or material, which reduces power consumption. Flowchart 900 will be explained with respect to the motor controller 400 shown in Figure 12, which is implemented in the gas engine exchange device 10. However, in some embodiments, the method of flowchart 900 may be implemented by other devices or modifications of the motor controller 400. 【0074】 Referring to Figure 18, the motor controller 400 monitors the current parameters of the motor 36 in block 905. In some embodiments, the motor controller 400 identifies overshoot conditions in the motor current. For example, in an embodiment of a cement mixer, when the mixer is first rotated, the material adheres to the walls of the mixer. At a certain rotational position, depending on the viscosity of the material, the material falls to the bottom of the mixer, resulting in a sharp decrease in the load on the mixer. As shown in Figure 19, this load reduction is demonstrated by an overshoot 1000 in the motor current curve 1010. As shown in Figure 20, in an embodiment of a cutting blade, an increase in the density of the material being cut is demonstrated by a slope 1100 in the motor current curve 1110. 【0075】 The motor controller 400 estimates the load state in block 910. For example, the motor controller estimates a load viscosity or density parameter as the load state. In the mixing embodiment, the rotational position and the magnitude of the overshoot 1000 are functions of the material viscosity. In some embodiments, the motor controller 400 uses a rotor position sensor 314 to determine the rotational position. In some embodiments, an external sensor 340 is a position sensor that provides the rotational position of the mixer. In the cutting embodiment, the magnitude and inclination of the inclined section 1100 are functions of the material density. In some embodiments, a profile generator 405 stores a profile of the equipment powered by the gas engine exchange device 10, which is associated with the motor parameters that sense the load state. In some embodiments, the profile includes a lookup table, an equation model, or a deep learning model. 【0076】 In block 915, the motor controller 400 sets the motor command speed based on the load state. In some embodiments, the motor controller 400 (e.g., profile generator 405) is programmed with a viscosity target value and adjusts the command speed of the motor 36 according to the estimated viscosity load state to drive or maintain the estimated viscosity load state near the viscosity target value. In some embodiments, for cutting applications, the motor controller 400 changes the command speed in proportion to the change in estimated density. In some embodiments, the motor controller 400 increases the command speed of the cutting blade as the density increases and decreases the command speed as the density decreases. In some embodiments, the motor controller 400 stores a model or lookup table that specifies an adjustment coefficient for the command speed as a function of the estimated load state. 【0077】 Figure 21 shows a mixing system 1200 including a frame 1205 supporting the gas engine exchange device 10 and a mixing drum 1210, the gas engine exchange device 10 being operable to rotate the mixing drum 1210. In some embodiments, the gas engine exchange device 10 of the mixing system 1200 implements the motor control described above with respect to Figures 18 and 19. 【0078】 Figure 22 shows a cutting system 1300, which is a cutting saw in the illustrated embodiment. The cutting system 1300 includes a housing 1305, a support arm 1310 coupled to and extending from the housing 1305, a cutting wheel 1315 supported by the support arm 1310, and a guard 1320 covering part of the periphery of the cutting wheel 1315. The cutting wheel 1315 can be a blade, an abrasive disc, or any other rotatable element capable of removing material from a workpiece. A first or rear handle 1325 extends from the rear of the housing 1305 in a direction substantially opposite to the support arm 1310. A trigger 1330 for operating the cutting system 1300 is located on the rear handle 1325. In the illustrated embodiment, the cutting system 1300 also includes a second or front handle 1335 wrapped around the upper portion of the housing 1305. The front handle 1335 and the rear handle 1325 provide gripping areas to facilitate two-handed operation of the cutting system 1300. The illustrated cutting system 1300 is a cordless electric saw and includes a gas engine exchange device 10. In some embodiments, the gas engine exchange device 10 of the cutting system 1300 implements the motor control described above with respect to Figures 18 and 20. 【0079】 Figure 23 is a flowchart 1400 of exemplary methods for loading and positioning according to several embodiments. For example, in an embodiment in which a gas engine exchange device 10 powers a cement mixer, the material may be loaded into the mixing drum when the mixing drum is positioned at a first rotational position and removed from the mixing drum when the mixing drum is positioned at a second rotational position. 【0080】 Referring to Figure 23, the motor controller receives a position control command in block 1405. In some embodiments, the user inputs the position control command using an external device 338 (see Figure 9). For example, the user may select a loading position or an unloading position by selecting a control displayed on the external device 338 or a user input device 322 (e.g., a push button). In some embodiments, the external device 338 is a wired or wireless remote control associated with the equipment driven by the gas engine exchange device 10. The position control command instructs the motor controller 400 to rotate the load to a specific position (e.g., a specific rotational position of the mixing drum of the cement mixer 1200). 【0081】 In block 1410, the motor controller 400 determines the loading position. In some embodiments, the motor controller 400 uses a rotor position sensor 314 to determine the position of the load. In some embodiments, an external sensor 340 is a position sensor that provides the position of the load (e.g., the rotational position of the mixing drum). 【0082】 In block 1415, the motor controller 400 controls the motor 36 based on the loading position. In some embodiments, the profile stored by the profile generator 405 includes position data such as loading or unloading positions, or loading positions for other positions associated with the equipment. In response to the position control command received in block 1405 and the loading position identified in block 1410, the motor controller 400 stops the motor 36 according to the loading position corresponding to the position control command. For example, the motor controller 400 may control the motor 36 to rotate until it reaches a specific rotational position of the mixing drum and then stop the motor 36 at that point. Before reaching the desired position of the load, the motor 36 may be decelerated to reduce position overshoot. 【0083】 In some embodiments, the loading position corresponding to a position control command is set by the manufacturer setting up the gas engine exchange device 10 or by the user of the device. For example, an external device 338 or a user input device 322 may be used to specify the loading position corresponding to a position control command. For example, the current loading position may be stored as a loading position target corresponding to a position control command in response to user input via the external device 338 or the user input device 322. In some embodiments, multiple position control commands may be provided corresponding to multiple loading position targets (e.g., loading and unloading positions), each of which may be associated with a desired loading position with a different load, which may be set in the motor controller 400 using a similar technique (e.g., via the manufacturer's setup or via a user using the external device 338 or the user input device 322). For example, the user input device 322 may include loading position setting buttons and unloading position setting buttons that provide input to the motor controller 400 to store the current loading position as a desired loading position and a desired unloading position, respectively. The desired stored loading and unloading positions may then be used by the motor controller 400 in block 1415, where one of the two stored positions is selected depending on whether a position control command requests a load to be rotated to the loading or unloading position. 【0084】 Power tools can be potentially exposed to ingress, vibration, and thermal elements, and the electronic components of power tools can be susceptible to damage from these elements. Various techniques may be used to protect one or more electronic components of the gas engine exchange device 10 from extreme environments. In one embodiment, excessive heat can damage the electronic components. In some embodiments, a protection technique against excessive thermal environments that improves tool performance includes using thermally conductive potting. Another technique includes placing one or more electronic components in a pressurized mineral oil bag to cool and dissipate heat, enabling improved performance. These techniques can also provide protection against environmental hazards such as the ingress of water or other substances. Additionally, open contacts may be covered with adhesive or low-pressure injection molds for charged or sensitive components to extend tool life under extreme conditions. In some applications, these techniques are also effective in reducing the risk from vibration and assisting in the release of strain on components soldered to circuit boards. 【0085】 Figure 24 shows a cooling system 1500 for one or more electronic components in the gas engine exchange unit of Figure 1. The cooling system 1500 includes an electronics housing 1510, a pump 1520, and a heat exchanger 1530. Vulnerable components of the gas engine exchange unit 10, such as the electronic processor 302 and memory 306 in Figure 9, may be housed within the electronics housing 1510. The pump 1520 circulates an inert fluid, such as mineral oil, through the electronics housing 1510 to remove heat. The heat exchanger 130 cools the inert fluid to remove heat from the cooling system 1500. In some embodiments, the heat exchanger may be a radiant heat exchanger, such as a fin-based heat sink, which radiates heat to the external environment. Air in the ambient environment may circulate over the fins to remove heat. The electronics housing 1510 also serves to provide protection from ingress, vibration, strain, etc. 【0086】 The mechanical system described above, driven by the gas engine exchange device 10, offers many advantages over conventional equipment driven by internal combustion engines, some of which are described below. 【0087】 In some embodiments, the gas engine exchange device 10 can be mated with a new device, and the memory 306 can be reprogrammed to optimize the gas engine exchange device 10 for operation with the new device. In some embodiments, the electronic processor 302 automatically recognizes what type of new device the gas engine exchange device 10 is mated with and manages the operation of the gas engine exchange device 10 accordingly. In some embodiments, the electronic processor 302 can automatically detect which device the gas engine exchange device 10 is mated with via radio frequency identification (RFID) communication with the new device. 【0088】 In some embodiments, the memory 306 is reprogrammable via either a Bluetooth or Wi-Fi communication protocol. In some embodiments, the electronic processor 302 has control modes for different uses of the same device. The control modes may be preset or user-programmable and may be programmed remotely via Bluetooth or Wi-Fi. In some embodiments, the electronic processor 302 utilizes master / slave device communication and cooperation so that the gas engine exchange device 10 can perform one-way control over the device, or so that an operator can perform one-way control over the gas engine exchange device 10 using a smartphone application. 【0089】 In some embodiments, the operator or original equipment manufacturer (OEM) is granted limited access to control the speed of the gas engine exchanger 10 through the electronic processor 302 via an interface such as a Controller Area Network (CAN). In some embodiments, the electronic processor 302 allows for a wider range of speed selection than a gasoline engine through a single set of gears in the gear train 110. For example, the control electronics 42 is configured to drive the motor 36 at less than 2,000 RPM, which is lower than any speed a gasoline engine can achieve, allowing the associated equipment to have a longer total run time than a gasoline engine over the full discharge of the battery pack 50. In addition, the control electronics 42 is configured to drive the motor above 3,600 RPM, which is higher than any speed a gasoline engine can achieve and has the ability to output more torque. The wider speed range of the motor 36 provides higher efficiency and capability than a gasoline engine. In some embodiments, the operator may have access to control the current drawn by the motor 36 in addition to the speed. 【0090】 In some embodiments, the electronic processor 302 is configured to record and report data. For example, the electronic processor 302 is configured to provide wired or wireless diagnostics for monitoring and reading the status of the gas engine exchange unit 10. For example, the electronic processor 302 can monitor and record the running time of the gas engine exchange unit 10, for example, in a rental scenario. In some embodiments, the motor 36 and the electronic processor 302 use regenerative braking to charge the battery pack 50. In some embodiments, the gas engine exchange unit 10 includes a DC output for lighting or accessories. In some embodiments, the electronic processor 302 can detect abnormalities or malfunctions of the gas engine exchange unit 10 via voltage, current, motion, speed, and / or thermocouples. In some embodiments, the electronic processor 302 can detect unintended use or shutdown of the gas engine exchange unit 10. If the equipment driven by the gas engine exchange unit 10 is not operating with its intended characteristics or is not being used correctly or safely, the electronic processor 302 can detect the abnormality and shut down the gas engine exchange unit 10. For example, the gas engine exchange device 10 may include one or more accelerometers that sense whether the gas engine exchange device 10 and the equipment are in the intended orientation. Also, if the electronic processor 302 determines that the gas engine exchange device 10 is not in the intended orientation (i.e., the equipment has tipped over), the electronic processor 302 may shut down the gas engine exchange device 10. 【0091】 In some embodiments, the gas engine exchange device 10 includes an accessible sensor support (not shown) electrically connected to a user-selectable sensor for use with some of the power equipment, such as an accelerometer, gyroscope, GPS unit, or real-time clock, allowing the operator to customize the variables sensed and detected by the electronic processor 302. In some embodiments, the electronic processor 302 can indicate the status of the battery pack 50, such as when the battery is depleted, to the operator via visual, auditory, or tactile notification. In some embodiments, the electronic processor 302 can operate an auxiliary motor separate from the motor 36 to drive an auxiliary device such as a winch. The auxiliary motor may be located inside or outside the gas engine exchange device 10. 【0092】 In some embodiments, the gas engine exchange device 10 may include digital control on a customizable user interface such as a touch display or a combination of knobs and buttons. In contrast, the analog gasoline engine does not include such digital control. In some embodiments, the user interface for the gas engine exchange device 10 may be modular, wired, or wireless, and may be mountable on the gas engine exchange device 10 or handheld. In some embodiments, the gas engine exchange device 10 may be controlled by remote control, including status indicators for certain characteristics of the gas engine exchange device 10, such as the charge and temperature of the battery pack 50. In some embodiments, the gas engine exchange device 10 may provide status indication by a remote programmable device.

Claims

[Claim 1] A gas engine exchange device, Housing and A battery receptacle, coupled to the housing and configured to removably receive a battery pack, The motor located inside the housing, A power take-off shaft that receives torque from the motor and protrudes from the side of the housing, A power switching network configured to selectively supply power from the battery pack to the motor, An electronic processor coupled to the power switching network and configured to control the power switching network to rotate the motor, Monitor motor current, Based on the motor current, the load state is estimated, The system includes an electronic processor configured to set the motor command speed based on the load condition, Gas engine exchange device. [Claim 2] The gas engine exchange device according to claim 1, wherein the electronic processor is configured to estimate the viscosity of a mixture contained in a mixer coupled to the power take-off shaft in order to estimate the load state. [Claim 3] The gas engine exchange apparatus according to claim 2, wherein the electronic processor is configured to estimate the viscosity based on the magnitude of the overshoot in the current signal associated with the motor, in order to estimate the viscosity. [Claim 4] The gas engine exchange apparatus according to claim 3, wherein the electronic processor is configured to estimate the viscosity based on the magnitude of the overshoot and the rotational position of the mixer, in order to estimate the viscosity. [Claim 5] The gas engine exchange device according to claim 2, wherein the electronic processor is configured to set the motor command speed based on the estimated viscosity and viscosity target value in order to set the motor command speed. [Claim 6] The electronic processor increases the motor command speed in accordance with the fact that the estimated viscosity is less than the viscosity target value, in order to set the motor command speed. The system is configured to set the motor command speed by decreasing the motor command speed if the estimated viscosity is greater than the viscosity target value. The gas engine exchange device according to claim 5. [Claim 7] The gas engine exchange device according to claim 1, wherein the electronic processor is configured to estimate the density of the material to be cut by a cutting blade coupled to the power take-off shaft in order to estimate the load state. [Claim 8] The gas engine exchange device according to claim 7, wherein the electronic processor is configured to estimate the density based on the gradient of a slope in a current signal associated with the motor, in order to estimate the density. [Claim 9] The gas engine exchange device according to claim 8, wherein the electronic processor is configured to change the motor command speed in proportion to the estimated change in density in order to set the motor command speed. [Claim 10] The aforementioned electronic processor is surrounded by a housing containing an inert fluid, A pump configured to circulate the inert fluid within the housing, The housing further comprises a heat exchanger coupled to the housing, The gas engine exchange device according to claim 1. [Claim 11] A method for operating a gas engine exchange device, comprising: a housing; a battery receptacle coupled to the housing and configured to removably receive a battery pack; a motor located inside the housing; a power take-off shaft receiving torque from the motor and protruding from the side of the housing; a power switching network configured to selectively supply power from the battery pack to the motor; and an electronic processor coupled to the power switching network and configured to control the power switching network to rotate the motor, The aforementioned electronic processor monitors the motor current, The electronic processor estimates the load state based on the motor current, The electronic processor includes setting the motor command speed based on the load state, method. [Claim 12] The electronic processor is used to estimate the load state. The electronic processor includes estimating the viscosity of the mixture contained in the mixer coupled to the power take-off shaft, The method according to claim 11. [Claim 13] The viscosity is estimated by the aforementioned electronic processor. The electronic processor includes estimating the viscosity based on the magnitude of the overshoot in the current signal associated with the motor. The method according to claim 12. [Claim 14] The viscosity is estimated by the aforementioned electronic processor. The electronic processor includes estimating the viscosity based on the magnitude of the overshoot and the rotation position of the mixer. The method according to claim 13. [Claim 15] The motor command speed is set by the aforementioned electronic processor. The electronic processor includes setting the motor command speed based on the estimated viscosity and viscosity target value. The method according to claim 14. [Claim 16] The motor command speed is set by the aforementioned electronic processor. The electronic processor increases the motor command speed in accordance with the fact that the estimated viscosity is less than the viscosity target value. The electronic processor includes reducing the motor command speed in accordance with the fact that the estimated viscosity is greater than the viscosity target value, The method according to claim 15. [Claim 17] The electronic processor is used to estimate the load state. The electronic processor includes estimating the density of the material to be cut by the cutting blade coupled to the power extraction shaft, The method according to claim 11. [Claim 18] The density is estimated by the aforementioned electronic processor. The electronic processor includes estimating the density based on the gradient of the slope in the current signal associated with the motor, The method according to claim 17. [Claim 19] The motor command speed is set by the aforementioned electronic processor. The electronic processor includes changing the motor command speed in proportion to the estimated change in density, The method according to claim 18.

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