Large equipment has to be able to complete a variety of tasks. The equipment has to be able to execute tasks that require great strength and power while being mobile. A variety of systems are including to execute these tasks, including a primary power source and other systems which may redeploy power from the primary power source, such as hydraulic systems and electrical systems.
Providing additional power to move bigger objects and lift bigger things usually means installing a larger engine with additional power. Additional power has often meant more fuel consumption. While engine efficiency has improved over time, fuel costs are still significant. Every gain in efficiency is meaningful. In addition, the equipment has to be reliable and long lasting, meaning that the pursuit of efficiency cannot overshadow the need for the equipment to be long lasting.
A power platform for a motorized work device that includes hybrid power sources is disclosed. The hybrid power system may include a hydraulic power source that provides power and stores power, an electric power source that provides power and stores power and a kinetic power source that provides power and stores power. The power platform may also include an engine that produces less power than engines for similar sized devices where the hydraulic power source, electric power source and kinetic power source provide additional power to the engine when required. The hydraulic power source, the electric power source and kinetic power source may also store power when excess power is available to be stored. Further, if the engine is under stress, additional power may be provided from at least one of the hydraulic power source, the electric power source and the kinetic power source.
The kinetic power source may include a high speed, low mass flywheel that is in communication with the power source. The hydraulic power source may include an accumulator that is filled if reverse pressure is presented to the hydraulic system along with a hydraulic pump/motor and hydraulic supply lines that communicate with the hydraulic pump/motor, the accumulator and the hydraulic supply lines. The electric power source may include an electricity storing device such as one or more batteries or capacitors that store electricity when reverse power is provided to a generating device along with an integrated starter-generator which is in communication with the drivetrain of the device and provides power as a motor when needed.
The system may operating in a variety of modes depending on a variety of factors including the location of the device, the current demands on the device, the start of charge of the hybrid systems and available power from the primary power unit. The decision on the mode to use may be made using a remote or distant computing device physically configured to make the decision. Further, the decision on which hybrid system to use store or provide additional power may be based on a plurality of functions that may vary based on a variety of inputs to the system. Of course, additional embodiments of the system are possible and are contemplated.
There are a variety of hybrid power source that may assist a main power source, each of which has its own advantages and disadvantages.
Referring to
Another form of power may be a hydraulic source.
Another hybrid power source 200 may be a kinetic power storage device 500.
Energy may also be supplied from the kinetic storage device 500 but using the kinetic energy stored in the spinning object 240 to supplement the main power source 205 or any other source 200. For example, a flywheel 240 may be the kinetic storage object and may be in communication with the crankshaft of an internal combustion engine 205 or the drivetrain to provide additional power to the main power source 205. Of course, the kinetic storage object 240 may provide power to an integrated starter/generator 245, for example, which may provide power to the other hybrid power sources 200 which may be stored by the other objects.
At a high level, the hybrid power devices 200 store power when excess power is available and provide power when additional power is needed. The decision on which hybrid power source is used to provide additional power and which power source is used to store power at which time may be based on a variety of factors which will be discussed further in this application in reference to
Referring again to
The power may also pass through a clutch 215. The clutch 215 may be engaged during most operations. The clutch 215 may be opened or disengaged when the machine 100 is at idle. The clutch 215 may also be open during engine off events. In such a situation, the engine 205 may be started without the burden of powering the hybrid systems 200 or other downstream loads. In addition, the hybrid systems 200 may be used to power the device 100 such as in creep mode when the main engine 205 is off.
The clutch 215 may also be in communication with a gear box 220 which may amplify or reduce the rotational motion and or power passing through the hybrid sources 200 and the main power source 205. From the gearbox 220, power may be in communication with a hydraulic pump/motor 225. In times of excess power, the hydraulic pump/motor 225 may operate to fill the hydraulic accumulator 230 with fluid under pressure. In times of power need, the force stored in the accumulator 230 may be released to provide force to the hydraulic pump/motor 225 which may communicate the power to the gearbox, 220, the clutch 215 and then the main power source 205.
The gearbox 220 may also be in communication with an additional mechanical continuously variable transmission 235 which may be in communication with a kinetic storage object 240 such as a flywheel. In times of excess power, the mechanical continuously variable transmission 235 may communicate power to the kinetic storage device 500 which may spin an object 240, thereby storing the energy. In times of power need, the kinetic energy stored in the kinetic storage object 240 may be release to the mechanical continuously variable transmission 235 which may communicate to the gearbox 220 and then to the main power source 205.
The gearbox 220 may also be in communication with an integrated starter/generator 245. The integrated starter/generator 245 may operate as a starter and a motor, adding power to the main power unit 205 when needed. The power for the integrated starter/generator 245 may come from an electrical storage device 250 such as a battery or capacitor. In addition, electrical accessories 255 may operate by drawing on the electrical storage device 250. In times when there is excess power, the integrated starter/generator 245 may spin and generate electricity which may be stored in the electronic storage device 250.
Logically, the main power source 205 may be in communication with the gearbox 220 which may provide power to the differential 265 and a planetary gear 260. In some situations, the main power source 205 and the hybrid power sources 200 may provide power to the planetary gears 260 which may then power the device 100. In other situations, the planetary gears 260 may provide excess force to the device 100 such as when the vehicle 100 is traveling downhill. This excess power may be used to provide power to the various hybrid systems 200 to be stored for a later time. Similarly, when the device 100 is braking, the excess force may be used to charge the various hybrid systems 200. In yet another aspect, when the main power source 205 is operating at a desired speed but the device 100 does not require all the power, the excess power may be diverted to the hybrid power sources 200 to be stored for future use.
Hybrid Modes
The device 100 may have a variety of modes. The decision on which mode to use may be based on a variety of factors.
At block 600, the device 100 operating status may be evaluated. In the illustration in
At block 605, it may be determined whether the device is traveling downhill or in a manner that generates excess force that may be converted into power. If the determination is true, the regeneration mode may begin at block 610. The regeneration mode is described further with reference to
At block 615, it may be determined whether the engine is producing excess power that may be converted into power that may be stored for future use by the hybrid power systems 200. If the power demand from the engine is below its capability, it may be desirable to increase the power production of the engine for the purpose of storing energy via the hybrid systems. For example, the current torque demand on the engine 205 may be low and excess torque may be available at the current engine 205 speed to be used to charge the hybrid power systems 200. If the determination is true, the generation mode may begin at block 620. The generation mode is further described with reference to
At block 625, it may be determined whether the engine 205 requires additional power. For example, the torque demanded may exceed the torque currently being produced by the engine 205. If the determination is true, at block 630 the assist mode may begin. The assist mode is further described with reference to
At block 635, it may be determined whether the power required by the device 100 is low enough that the main power source 205 is not required and that the power required may be provided by the hybrid power sources 200. For example, the device 100 may have to slowly creep and the hybrid power sources 200 may be capable of providing the needed power without starting the engine 205 and using fuel. If the determination is true, at block 640, the creep mode may begin. The creep mode is discussed further in reference to
At block 645, it may be determined whether the device is braking. Braking traditionally is accomplished by applying a slowing force, such as clamping onto a rotor. Braking also may be accomplished by converting the slowing force into energy that may be stored. For example, a kinetic storage device 500 may be connected to the wheels that need to be slowed and the force of turning the kinetic storage object 240 may cause the wheels to slow while the energy is stored in the kinetic storage device 500. Similarly, the wheel to be slowed may be in communication with a generator (or an integrated starter/generator 245) which may slow the wheel and generate electricity which may be stored in a storage device 250 like a battery or capacitor. Not surprisingly, the wheel to be slowed may also be in communication with a hydraulic pump/motor which may store hydraulic fluid under pressure in an accumulator 230 and may cause the wheel to slow. If the determination at block 645 is true, at block 650 the braking mode may begin. The braking mode is discussed further in reference to
At block 655, it may be determined whether the device 100 has entered starting mode. In starting mode, a starter (or an integrated starter/generator 245) may use power from a battery 250 to spin a motor 245 in communication with the engine 205 such that it will start. In other embodiments, power from an accumulator 230 may be transferred through a hydraulic motor 225 to the gearbox 220 which may be in communication with the engine 205 which may then spin and start. The starting mode is discussed further in reference to
Regeneration Mode
Generation Mode
The clutch 215 may also be in communication with a gear box 220 which may amplify or reduce the rotational motion and or power passing through the hybrid sources 200 and the main power source 205. From the gearbox 220, power may be in communication with a hydraulic pump/motor 225. In times of excess power, the hydraulic pump/motor 225 may operate to fill the hydraulic accumulator 230 with fluid under pressure. In some embodiments, the hydraulic pump/motor 225 is electric and is in communication with the electrical system of the device 100 including the electrical storage device 250. In other embodiments, the hydraulic pump/motor 225 is mechanically driven and is in mechanical communication with the gearbox 220. And in yet an additional embodiment, both mechanical and electric hydraulic pump/motors 225 may be used and managed as circumstances merit.
The gearbox 215 may also be in communication with an additional mechanical continuously variable transmission 235 which may be in communication with a kinetic storage device 500 such as a flywheel 240. In times of excess power, the mechanical continuously variable transmission 235 may communicate power to the kinetic storage device 500 which may spin an object 240, thereby storing the energy.
The gearbox 220 may also be in communication with an integrated starter/generator 245. The integrated starter/generator 245 may operate as a starter and a motor, adding power to the main power unit 205 when needed. The power for the integrated starter/generator 245 may come from an electrical storage device 250 such as a battery or capacitor. In addition, electrical accessories 255 may operate by drawing on the electrical storage device 250. In times when there is excess power, the integrated starter/generator 245 may spin and generate electricity which may be stored in the electronic storage device 250.
Logically, the main power source 205 may be in communication with the gearbox 220 which may provide power to the differential 265 and a planetary gear 260 which may then power the device 100. In yet another aspect, when the main power source 205 is operating as a desired speed but the device 100 does not require all the power, the excess power may be diverted to the hybrid power sources 200 to be stored for future use.
Assist Mode
Creep Mode
Braking Mode
Starting Mode
Hybrid Decision Making
In block 1320, the state of charge and the power path efficiency of each hybrid system may be scored. The scoring may involve subjecting the state of charge to a charge function and the power path efficiency to a path function and the results of the function may be totaled. The charge function and path function may vary based on a variety of factors, such as the type of power demanded, the anticipated length of time the power will be demanded, the environmental factors, etc. For example, if the device 100 is working in extreme cold environment, batteries 250 may be more quickly depleted of power and the function may take this issue into account.
At block 1330, the power capability of each hybrid system 200 may be evaluated. For example, if excess power is available, it may be stored in one of the hybrid systems 200 if there is sufficient capacity to store the power. If the hybrid system 200 storage is already full, then it may be physically impossible to store more. Similarly, if a power storage device is currently storing little power, the power storage device in question may be the first choice to receive excess power.
At block 1340, the scores from block 1320 are reviewed. Based on the review, power may be obtained from the hybrid system 200 or may be allocated to be stored by the various hybrid systems 200. In addition, if one hybrid system 200 is “full” or at capacity of stored energy, the excess energy may be supplied to another hybrid storage system 200. Similarly, if energy is needed, the scores from block 1320 may be reviewed to determine a hybrid source 200 to be used for excess power. At a high level, whether storing or releasing power, the hybrid system 200 with the highest power score may be selected first. When considering storing power, a high score results from having a low state of charge but high efficiency and when considering releasing power, a high score may result from having a high state of charge and high efficiency.
At block 1400, the state of charge of each hybrid power source 200 may be determined. Each hybrid power source 200 may store and provide power. At some times, all the hybrid power sources 200 may be fully charged. At other times, all the hybrid power sources 200 may have no charge. Of course, there may be other situations in which some of the hybrid systems 200 are fully charged while other hybrid systems 200 have less of a charge. As mentioned previously, the hybrid sources 200 and storage systems may include a hydraulic source 230, an electric source 250 and a kinetic object 240 but other hybrid sources 200 are possible and are contemplated.
At block 1410, a current power score may be determined for each hybrid power source 200. The power score may be a function of the current state of charge and state of efficiency of each of the hybrid power sources 200. The efficiency may relate to the power in demand and the ability to deliver power from the hybrid device 200. For example, if the demand is for hydraulic power, the power stored in the hybrid accumulator 230 may be more readily available than power stored in batteries 250 that would have to be transmitted to the hydraulic pump/motor 225.
In some situations, it may make sense to use the current hybrid power source 200 until the current hybrid power source 200 falls below a minimum power level. As switching hybrid power sources 200 may take time and power loss, the hybrid power source 200 that is currently providing additional power may continue to provide additional power even if the current power source has less excess power than some of the other hybrid power sources 200. In some embodiments, the function for the current power source may give an additional weight making it more likely the present hybrid source 200 in use will continue to be used. Similarly, if excess power is currently being sent to a first hybrid storage device 200, it may be easier to continue to send power to that hybrid storage device 200. As such, the current storage device 200 may be given an additional weight making it more likely that power will continue to be stored in the same device 200.
At block 1420, if there is power demand, power may be provided from the hybrid power source 200 with the highest current power score. As mentioned previously, the scores may be determined by a function. A simple function may be to simply compare the stored power against the maximum stored power and the score may reflect the amount of empty space in the hybrid storage device 200 as a percentage. If power is needed, the hybrid source 200 with the highest percentage may be used and if power is to be stored, the source with the lowest percentage may be used.
Of course, the function may be more complex. For example, the function may take into account a variety of factors. As previously mentioned, the type of power demanded or excess power to be stored may result in the function weighting toward a particular hybrid storage device 200 over another. Similarly, some hybrid devices 200 may be better at providing instantaneous power than other hybrid devices 200 and if the power demanded is instantaneous power, then an increased weight may be placed on the functions for the hybrid devices 200 that are most capable of providing instantaneous power.
Further, a processor with a memory and an input/output may control and keep track of the decisions of the hybrid power system. To provide ever improving performance, the system may learn from past instances of needing power or storing power and may follow successful outcomes from the past.
At block 1430, if the power demand is beyond the capabilities of the hybrid power source 200 with the highest current power score, additional power may be provided from the hybrid power source 200 with the next greater power score. In this embodiment, power from two or more hybrid sources 200 may be used to add power to the main power source 205. In some embodiments, the plurality of hybrid sources 200 may act in concert and in other embodiments, the first hybrid source 200 may operate until it is at a state of exhaustion and then the second hybrid source 200 may assist until it is at a state of exhaustion, etc.
At block 1440, if there is excess power, it may be determined if any of the hybrid powers sources 200 has excess capacity. For example, some of the hybrid sources 200 may not be fully charged and the excess power may be used to charge one or more of the hybrid sources 200. If none of the hybrid sources 200 has excess capacity, then no effort may be made to store the excess power.
At block 1450, if any of the hybrid power sources 200 have excess capacity, power may be added to the hybrid power sources 200. The decision of which hybrid power source 200 to add power may be based on a variety of factors. In one embodiment, the hybrid power source 200 that has the lowest power score may be charged first, the hybrid power source 200 that has the next lowest score may be charged next, etc. In some embodiments, multiple hybrid sources 200 may be charged at the same time. In other embodiments, a first hybrid source 200 may be charged, a second hybrid source 200 may be charged, etc.
Computing Elements
Referring again to
The portable computing device 1600 may be able to communicate with a remote computing device 1700. The portable computing device 1600 may be able to communicate in a variety of ways. In some embodiments, the communication may be wired such as through an Ethernet cable, a USB cable or RJ6 cable. In other embodiments, the communication may be wireless such as through Wi-Fi (802.11 standard), Bluetooth, cellular communication or near field communication devices. The communication may be direct to the computing device 1700 or may be through a communication network 1620 such as cellular service, through the Internet, through a private network, through Bluetooth, etc.
User Display of System Status
The display 1800 may also display the current status of the system, such as the torque currently demanded 1850 and the current status 1855 such as assisting, charging, resting etc. In addition, indications may be displayed to obtain even more information about the electric hybrid system 1860, the hydraulic system 1865 and the kinetic storage system 1870. An option may be presented to a user to turn on 1872 and off 1874 the hybrid electric system, turn on 1876 or off 1878 the hybrid hydraulic system or turn on 1880 or off 1882 the hybrid kinetic storage system.
The display may display additional information or less information depending on the current state of the device 100 and the hybrid systems 200. In addition, a user may be able to modify the display as desired, such as including some indications and eliminating others or placing the indications on screens that are down in further levels.
Additional Considerations for the Hybrid Systems
In some embodiments, the function used to score the hybrid power sources 200 may take into account the type of energy that is available to be stored. For example, if the device 100 is traveling downhill, energy may be stored in the kinetic source 500 as the energy may be easily transferred to the kinetic source 500. In such a case, the function may be modified to add additional weight to direct the excess energy toward the most logical hybrid storage source 200. Similarly, in other designs, the downhill force may be easily converted into electricity that may be easily stored in the electric storage devices 250. In such a case, the function may be modified to add additional weight to direct the excess energy toward the most logical storage source 200. As yet another example, if the excess power is hydraulic pressure, it may be most logical to store the hydraulic pressure in the hydraulic accumulator 230. In such an embodiment, the function may be modified to add additional weight to direct the excess energy toward the most logical storage source, specifically, the hydraulic accumulator 230.
The excess energy may also exist when the main power source 205 is not operating at a full load. The excess power that is not being used but the current power load may be used to add power to the hybrid power sources 200. For example, an engine may operate at 2,000 rpm and a given amount of power may be available from the engine at 2,000 rpm without taxing the engine 205. One or more hybrid systems 200 may tap into the excess power and from the engine 205 to provide power to one or more of the hybrid system 200 to be stored.
Further, a processor with a memory and an input/output may control and keep track of the decisions of the hybrid power system. Thus, the system may learn from past instances of storing excess power and may follow successful outcomes from the past. The system may continually learn and improve the scoring functions and decision making process. For example, the system may track in a memory past inputs to the system in a manner which allows the inputs to be searched and analyzed. Some possible inputs include the time of day, the length of operations, the source of the power demand, the current functions demand power, the previous functions demanding power, etc.
The inputs may be stored locally such as on the portable computing device 1600 or remotely such as on the server 1700. As an example, the inputs may be stored in a cloud storage system making the inputs and analysis available to all machines operating. In yet another embodiment, all the data is forwarded to a central analysis site where the data is analyze and continual improvements are made to the functions based on the inputs. Further, the data may be analyzed for errors and maintenance reminders that may need attention on the device 100 in question or across multiple devices.
In accordance with the provisions of the patent statutes and jurisprudence, exemplary configurations described above are considered to represent a preferred embodiment of the invention. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.