ELECTRONIC CONTROL FOR A ROTARY FLUID DEVICE
A fluid system is provided including a fluid pump having an output and an electric motor coupled to the fluid pump. The electric motor is adapted to operate the fluid pump in response to an electrical signal. A controller adapted to communicate the electrical signal to the electric motor, the controller including an initial lookup table having initial performance data related to the fluid pump and the electric motor. The initial performance data from the initial lookup table and sensed performance data applied to a modifiable lookup table are used by the controller to set aspects of the electrical signal communicated to the electric motor to achieve a desired system pressure generated by the fluid pump. A pressure sensor in communication with the output that is adapted to communicate a sensed system pressure to the controller, the controller being adapted to update the modifiable lookup table based on a difference between the desired system pressure and the sensed system pressure to minimize variation between the sensed system pressure and the desired system pressure.
This application is being filed on Oct. 29, 2014, as a PCT International Patent application and claims priority to U.S. Patent Application Ser. No. 61/896,683 filed on Oct. 29, 2013, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUNDAn electronic controlled rotary fluid device according to the present disclosure improves robustness of the device identified in U.S. Patent Publication Number 2010/0021313 for systems in which the variation in performance due to external factors such as fluid temperature is to be reduced.
SUMMARYSome or all of the above needs and/or problems may be addressed by certain examples of the disclosure. Certain examples of the disclosure can include systems and methods for controlling a rotary fluid device. A control methodology can be applied to single motor-pump configurations and multiple motor-pump configurations. In addition, the single and multiple motor-pump configurations may only require a single pressure sensor for an entire power pack system. The single pressure sensor can be integrated into a control loop to periodically provide pressure data used to reduce variation in the performance of the system. Accordingly, the sensed pressure data may initiate an updating step causing a recalculation to the parameters used to control the fluid device system.
Other facets of the control methodology can be implemented by a controller that allows for the system to further refine current commands sent to a motor by using a dynamic current command update. In an example, the dynamic current command update can be applied to maintain steady state operation, when a flow demand or system pressure may cause the fluid device system to operate in a transient state. In controlling the system, the periodic sampling of the pressure sensor of system can be used to determine if an update to the operating parameters should be made. For example, when the desired system pressure and the sensed system pressure exceed a predetermined threshold, the operating parameters may be updated to minimize the difference between the current and desired system pressure. In the proceeding system operations, updates may serve as the system parameters. However, the control methodology also possesses fail safe mechanisms, wherein when certain operating parameters exceed predetermined thresholds the system may revert back to initial factory settings.
In other examples, the controller uses updated operating parameters to perform control operations on multi-motor pump systems. For example, the controller can maintain and update a lookup table for each motor-pump configuration in the system. In the process of maintaining the lookup tables, the controller can recalibrate the lookup table for each configuration. When the system output flow is sensed by the pressure sensor and the flow can be isolated to a single motor-pump configuration, the recalibrations can be completed. The controller can also be configured to determine the operation of the pressure sensor by comparing the operation of the sensor by alternating the active motor-pump configuration. In another example, the controller can be configured to statistically differentiate the current operation from the initial operation of the system using the system operating parameters to determine the useful life of system components. In addition, the statistical calculations may be used to predict component failure. Further, the controller can operate the system in a power savings mode, wherein various configurations and alternating activity of multi-motor-pumps can be used to maximize the useful life of the motor-pumps, while maintaining a requested system flow output and pressure. The power saving mode may be applied in controller examples where the controller is configured with sub-controllers that control an individual motor-pump and communicate with each other.
Reference will now be made in detail to the exemplary aspects of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like structure.
An aspect of the present disclosure relates to a fluid system that has a fluid pump having an output, an electric motor that operates the fluid pump in response to an electrical signal, a pressure sensor, and a controller. The controller communicates the electrical signal derived from a modifiable lookup table. The pressure sensor communicates with the controller and the controller updates the modifiable lookup table based on a difference between the desired system pressure and the sensed system pressure to minimize variation between the sensed system pressure and the desired system pressure.
Another aspect of the present disclosure relates to the fluid system also including a temperature sensor for sensing a hydraulic fluid temperature of hydraulic fluid passing through the fluid pump. The controller also includes a plurality of initial lookup tables and plurality of modifiable lookup tables corresponding to different hydraulic fluid temperatures. Based on the hydraulic fluid temperature sensed by the temperature sensor, the controller selects an appropriate modifiable lookup table from the plurality of updatable lookup tables.
Another aspect of the present disclosure relates to the controller in the fluid system being configured to monitor the sensed motor speed over time and determine whether an acceleration condition exists. The controller is also configured to modify the electrical signal sent to power the motor when the acceleration condition exits.
Another aspect of the present disclosure relates to the controller in the fluid system being configured to perform a recalibration routine to update the modifiable table. The recalibration steps may comprise receiving sensed performance data from a sensor; retrieving initial performance data related to the fluid pump and the electric motor from a memory module; storing the sensed performance data and the initial performance data in a modified lookup table; in response to a sensed measurement from the pressure sensor, comparing the sensed performance data and the initial performance data to determine a correlation between the sensed performance data, the initial performance data and the desired system pressure; generating an updated version of the modifiable lookup table; using the updated version of the modifiable lookup table to send a motor current command signal to the controller.
Another aspect of the present disclosure relates to a fluid system that has a plurality of fluid pumps, each pump coupled to a motor. The fluid system includes a junction location for combining fluid output flow from the fluid pumps, and wherein a pressure sensor is positioned at or downstream of the junction location. In another example, each motor is controlled by a sub-controller.
Another aspect of the present disclosure relates to the controller in the fluid system being configured to determine pressure sensor functionality in multi-motor-pump configurations. The steps to determine pressure sensor functionality may comprise sensing a first pressure measurement while first individual pump in the plurality of pumps produces an output flow and the remainder pumps in the plurality of pumps do not produce a flow output; determining whether the first pressure measurement is an anomaly based on a predetermined threshold for system pressure; in response to determining that the first pressure measurement is an anomaly, sensing a second pressure measurement wherein the second pressure measurement is based on alternating the first individual pump to a no flow output state and producing the flow output from a second individual pump from the remainder pumps; and determining whether the second pressure measurement is an anomaly based on the predetermined threshold for system pressure.
Referring now to the drawings,
The controller 106 further includes a plurality of outputs including a voltage output, a phase current output, and a phase angle output. In the subject example, each of the plurality of outputs is in electrical communication with the electric motor 104.
The controller 106 further includes a circuit having a microprocessor and a storage media. In an example, the microprocessor may be a field programmable gate array (FPGA). The FPGA is a semiconductor device having programmable logic components, such as logic gates (e.g., AND, OR, NOT, XOR, etc.) or more complex combinational functions (e.g., decoders, mathematical functions, etc.), and programmable interconnects, which allow the logic blocks to be interconnected. In an example, the FPGA can be programmed to provide voltage and current to the electric motor 104 of the rotary fluid device system 100 such that the rotary fluid device system 100 responds in accordance with desired performance characteristics (e.g., constant horsepower, pressure compensation, constant speed, constant pressure, etc.). In another example, the storage media can be volatile memory (e.g., RAM), non-volatile memory (e.g., ROM, flash memory, etc.), or a combination of the two. The storage media includes program code for the FPGA, an initial lookup table 120 and a modified (dynamic) lookup table 116.
Motor speed command 128 is based on a modifiable lookup table 116, which consolidates the pump and motor characteristics (e.g., torsional, volumetric, and electrical efficiency) into a single curve of steady state motor speed versus current that results in the desired pressure 132 versus flow at the output of the pump 102. This approach may be modified to use a family of curves for external factors, which may have a strong influence on the motor-pump performance. Fluid temperature 138 is an example of one such variable illustrated in
The fast speed response required by typical hydraulic consumers 124 will be satisfied by the internal motor speed control loop based on the lookup tables (120 and 116) as described in U.S. Patent Publication Number 2010/0021313. Unlike U.S. Patent Publication Number 2010/0021313, the adjustments to the control tables described herein can be applied to the steady state performance—an adjustment/re-calibration control should not respond to transient conditions including pressure changes during flow transients. This is achieved by requiring persistence in the operating condition (e.g., greater than about 0.5 seconds) prior to invoking the control and monitoring logic described. In referring to
One technical effect of certain examples of the disclosure is that the control methodology adjusts the motor-pump steady state operating characteristics, which can be considered a slow control loop that adjusts the pump performance at a very slow rate (e.g., less than about 1 Hz). By adding a pressure sensor 108 between the pump outlet port 102 and the hydraulic consumers 124, the pump control lookup table 120 can be modified in order to minimize the variation in the outlet pressure. A pressure sensed 130 by the sensor 108 is compared with a desired set pressure 132 (e.g., 3000 psi) and the difference is added as an error signal to adjust the speed versus current modified lookup table 116 (possibly as an outer proportional-integral-derivative (PID) control, although other control schemes are possible).
In another example as depicted in
In referring to
Referring to
Referring to
In
Any detected faults or prediction of faults to occur will be communicated outside of the control system through an appropriate interface, such as an aircraft user interface. These communications can be used by a system controller or maintenance computer to direct action (e.g., maintenance activity or reconfiguration of the aircraft system).
The motor-pump control described herein is robust as described above and fail safe. In the event of pressure sensor failure (e.g., detectable by a time history similar to curve 7128 but differentiated from normal transient flow response by persistence greater than about 0.5 seconds for instance), the motor 104 and pump 102 will continue operating with the data table as constructed just prior to loss of the signal. If the error is too great (exceeds a pre-determined threshold 702), the motor 104 and pump 102 will revert to the initial lookup table coded in read-only memory at the factory. In this condition the motor 104 and pump 102 would operate at a lower operating pressure, but would still be available to power the hydraulic consumers 124.
If a temperature sensor signal is lost (broken cable for instance), the pressure sensor 108 will continue to update the lookup table 116 to control the motor-pump device to the set pressure.
If performance of the motor 104 and pump 102 degrades to a point where the steady state current exceeds the limit allowed by the electrical power distribution system, the motor-pump control 106 can be set to reduce the set pressure to continue operation. Trending, as described above, can be used to determine the maximum duration of safe operation within an operating threshold based on the maximum current allowed and the minimum pressure required.
Referring to
Referring still to
In order to distinguish each motor-pump performance from the others for the purpose of calibrating the modifiable lookup table 116 as described in the example of
In one example, during conditions where there is no requirement for all of the parallel motor-pumps to remain powered simultaneously (e.g., steady cruise in an aircraft hydraulic system), the power packs can be individually powered and calibrated (e.g., only one motor-pump is powered at a time) using the common pressure sensor 814 illustrated in
In another example, during conditions where a total flow rate demanded by the hydraulic consumers 828 is less than the maximum flow capacity of a single pump, the remaining pumps can be commanded to operate at reduced pressure (e.g., 1500 psi). In this case, the pump(s) set to operate at lower pressure will have their output flow blocked by the outlet check valve (822, 824) and will not contribute to the system flow. The pump operating at full pressure may be calibrated using the methodology described above in reference to
Similar to the calibration mode described above, it is possible to reduce the power consumed by a dual motor-pump power pack by reducing the pressure of one of the pumps to a low pressure setting (e.g., 1500 psi), the alternate pump will maintain the required system pressure (e.g., 3000 psi) and hold the reduced pressure pump check valve closed. If a high flow demand is detected by a low pressure in combination with the primary pump reaching maximum speed or a speed above a predetermined threshold (e.g., 90% speed), the lower pressure pump will immediately exit power savings mode and provide supplemental flow to the system at the rated system pressure (e.g., 3000 psi).
It may be desirable to add a communication link between the motor-pump sub-controllers (818, 820) to reduce the individual motor-pump power/energy extraction, to minimize wear and tear and/or to minimize the audible noise generated by the power pack system 800. For example, if a dual motor-pump power pack is used and it is determined that one of the motor-pumps will operate in the low pressure power savings mode for most of the system life, an additional monitoring and control function may be used to track the motor-pump usage (e.g., time at torque/speed for the individual motors) and balance the power savings mode between the two units. One such method is to always opt to operate the motor-pump with the highest damage ratio (calculated as integral of input electrical power over the operating time) in power savings mode. This will balance the wear and tear between the two motor-pumps (802, 804, 806, 808) and maximize system life.
A communication linkage between sub-controller 1 (818) and sub controller 2 (820) may also be used to prevent the individual motor-pumps from operating at maximum speed (or minimize the time operating at or near maximum speed) by balancing the loads between the two motors (802, 806). For example, if a large hydraulic consumer 828 flow is demanded, the typical control will cause one motor-pump to ramp-up to near full speed while the other, potentially in a lower pressure power savings mode, will continue to operate at a near zero speed. Alternatively, a system monitoring and control function may be used to command the two pumps (804, 808) to equal speeds, whereby each pump will output half of the system flow demand by operating at one-half its rated speed. This has the advantage of reducing the typical wear and tear on the otherwise high speed motor-pump as well as reducing the audible noise levels. To balance the power savings with the reduced speed objective, a speed threshold may be used on the primary pump to determine when the second pump should be powered to supplement the system flow. For example, the second motor-pump may be commanded out of low pressure power savings mode if the primary motor-pump speed exceeds 25% of its rated value.
Additionally, temperature sensors (830, 832) on the motor-pumps can be used by a monitoring and control function to adjust which motor-pump is providing system flow based on the individual motor temperatures. This can potentially be used to permit safe operation of the power pack if the usage, duty cycle, or failure of one of the motor-pumps causes one of the motor-pumps to overheat. In this case, the overheating motor-pump will be commanded into a lower power state (or off depending on the severity of the overheat condition) and the other (in a dual motor-pump arrangement) will be commanded into full pressure mode.
Method 1000 proceeds to Decision Block 1025 from Block 1020 and a determination is made whether the second pressure measurement is an anomaly. If it is determined that the second sensed pressure is an anomaly, then the YES branch is followed and the method continues to block 1035. At Block 1035, a responsive action may be required to address the pressure sensor. Referring back to Decision Block 1025, if it is determined that the second pressure measurement is not an anomaly, then the NO branch is followed and the method 1000 continues to Block 1030 where a responsive action may be required for the first pump. In addition, method 1000 can be applied to a fluid device system where there are more than two pumps, where active pump operational status can be rotated through each pump in the plurality to determine the operational efficiency of each pump, as well as determine the operation of the pressure sensor.
Accordingly, blocks of the block diagrams and flow diagrams support combinations of means for performing the specified functions, combinations of elements or steps for performing the specified functions and program instruction means for performing the specified functions. It will also be understood that each block of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and flow diagrams, can be implemented by special purpose, hardware-based computer systems that perform the specified functions, elements or steps, or combinations of special purpose hardware and computer instructions.
While the disclosure has been described in connection with what is presently considered to be the most practical of various examples, it is to be understood that the disclosure is not to be limited to the disclosed examples, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Various modifications and alterations of this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of this disclosure, and it should be understood that the scope of this disclosure is not to be unduly limited to the illustrative examples set forth herein.
Claims
1. A fluid system comprising:
- a fluid pump having an output:
- an electric motor coupled to the fluid pump, the electric motor being adapted to operate the fluid pump in response to an electrical signal;
- a controller adapted to communicate the electrical signal to the electric motor, the controller including an initial lookup table having initial performance data related to the fluid pump and the electric motor, wherein the initial performance data from the initial lookup table and sensed performance data applied to a modifiable lookup table are used by the controller to set aspects of the electrical signal communicated to the electric motor to achieve a desired system pressure generated by the fluid pump; and
- a pressure sensor in communication with the output that is adapted to communicate a sensed system pressure to the controller, the controller being adapted to update the modifiable lookup table based on a difference between the desired system pressure and the sensed system pressure to minimize variation between the sensed system pressure and the desired system pressure.
2. The fluid system of claim 1, wherein the initial lookup table establishes a relationship between motor current, motor speed, and the desired system pressure.
3. The fluid system of claim 1, further comprising a motor speed sensor for communicating a sensed motor speed to the controller, wherein the electrical signal includes a motor current command, and wherein the controller determines a value of the motor current command for achieving the desired system pressure.
4. The fluid system of claim 1, further comprising a temperature sensor for sensing a hydraulic fluid temperature of hydraulic fluid passing through the fluid pump, wherein the controller includes a plurality of initial lookup tables and plurality of modifiable lookup tables corresponding to different hydraulic fluid temperatures, and wherein the controller selects an appropriate modifiable lookup table from the plurality of updatable lookup tables based on the hydraulic fluid temperature sensed by the temperature sensor.
5. The fluid system of claim 4, wherein the controller is configured to monitor the sensed motor speed over time to determine whether an acceleration condition exists, and wherein the controller is configured to modify the motor current command when the acceleration condition exits.
6. The fluid system of claim 5, wherein the controller adjusts a magnitude of the motor current command based on a calculation to maintain the desired system pressure when the acceleration condition is detected.
7. The fluid system of claim 1, further comprising a current sensor for sensing a sensed current provided to the motor, wherein the controller is configured to compare the sensed current with a desired current corresponding to a value of the motor current command, wherein the comparison between the sensed current and the desired current results in a motor control signal, and wherein the controller modifies the motor control signal to compensate for variations between the sensed current and the desired current.
8. The fluid system of claim 1, wherein initial data corresponding to the initial lookup table is stored in a memory module of the controller.
9. The fluid system of claim 1, wherein a recalibration routine is used to update the modifiable lookup table based on the sensed system pressure sensed while the fluid system is operating at steady state.
10. The fluid system of claim 1, wherein the controller is configured to perform a recalibration routine to update the modifiable table, wherein the recalibration routine comprises:
- receiving sensed performance data from a sensor;
- retrieving initial performance data related to the fluid pump and the electric motor from the initial lookup table;
- storing the sensed performance data and the initial performance data in the modified lookup table;
- in response to a sensed measurement from the pressure sensor, comparing the sensed performance data and the initial performance data to determine a correlation between the sensed performance data, the initial performance data and the desired system pressure;
- generating an updated version of the modifiable lookup table; and
- using the updated version of the modifiable lookup table to send a motor current command signal to the controller.
11. The fluid system of claim 10, wherein determining a correlation between the sensed performance data, the initial performance data, and the desired system pressure comprises calculating a least squares error of an operating point between sensed performance data and the initial performance data.
12. The fluid system of claim 11, wherein generating an updated version of the modifiable lookup table is based on maintaining the desired system pressure.
13. The fluid system of claim 12, wherein generating an updated version of the modifiable lookup table further comprises reducing the least squares error of the operating point between the sensed performance data and the initial performance data.
14. The fluid system of claim 11, wherein the controller is further configured to determine remaining life of a component of the fluid system, wherein determining the remaining life comprises comparing the correlation between the sensed performance data and the initial performance data to at least one threshold over a time period.
15. The fluid system of claim 1, wherein the fluid pump is one of a plurality of fluid pumps, wherein each one of the plurality of fluid pumps is coupled to a motor, wherein the fluid system includes a junction location for combining fluid output flow from the fluid pumps, and wherein the pressure sensor is positioned at or downstream of the junction location and wherein each motor is controlled by the controller.
16. The fluid system of claim 15, wherein the controller is further configured with a plurality sub-controllers to individually control each electric motor and wherein the controller establishes a communication link between the plurality of sub-controllers.
17. The fluid system of claim 15, wherein check valves are positioned between each pump in the plurality of pumps and the junction location.
18. The fluid system of claim 15, wherein the controller operates an individual pump or a combination of fluid pumps depending upon a demand placed on the fluid system.
19. The fluid system of claim 17, wherein the fluid pump is one of a plurality of fluid pumps incorporated into a power pack controlled by the controller, wherein the power pack includes a power pack outlet that receives a total flow provided by the fluid pumps.
20. The fluid system of claim 19, wherein check valves are provided between the fluid pumps and the power pack outlet, wherein the total flow passes through a power pack outlet filter, and wherein the pressure sensor is positioned downstream from the power pack outlet filter.
21. The fluid system of claim 15, wherein the controller is configured to recalibrate the modifiable lookup table of an individual pump in the plurality of pumps, wherein the individual pump is powered during the fluid system operation with remaining pumps in the plurality of pumps unpowered.
22. The fluid system of claim 21, wherein the controller is configured to recalibrate the modifiable lookup table of the individual pump in the plurality of pumps, wherein the individual pump that is powered is alternated.
23. The fluid system of claim 20, wherein the controller is configured to recalibrate the modifiable lookup table of the individual pump in the plurality of pumps, wherein the individual pump in the plurality of pumps is operated at a desired system pressure and remaining pumps in the plurality of pumps are operated at a pressure lower than the desired system pressure, wherein output of the remaining pumps is blocked by the attached check valves.
24. The fluid system of claim 23, wherein the controller is configured to recalibrate the modifiable lookup table of the individual pump in the plurality of pumps, wherein the individual pump that operates at the desired system pressure is alternated.
25. The fluid system of claim 10, wherein the controller is configured to monitor the correlation, wherein when the correlation exceeds the threshold, a responsive action is triggered, wherein the responsive action comprises the fluid system reverting to operate based on initial performance data from an initial lookup table.
26. The fluid system of claim 15, wherein the controller is configured to determine the pressure sensor functionality, wherein determine the pressure sensor functionality comprises:
- sensing a first pressure measurement while a first individual pump in the plurality of pumps is producing an output flow and remainder pumps in the plurality of pumps are not producing a flow output;
- determining whether the first pressure measurement is an anomaly based on a predetermined threshold for system pressure;
- in response to determining that the first pressure measurement is an anomaly, sensing a second pressure measurement wherein the second pressure measurement is based on alternating the first individual pump to a no flow output state and producing the flow output from a second individual pump from the remainder pumps; and
- determining whether the second pressure measurement is an anomaly based on the predetermined threshold for system pressure.
27. The fluid system of claim 26, wherein the controller is configured to determine the pressure sensor functionality, wherein determine the pressure sensor functionality further comprises, in response to determining that the second pressure measurement is an anomaly, performing a responsive action on the pressure sensor.
28. The fluid system of claim 26, wherein the controller is configured to determine the pressure sensor functionality, wherein determine the pressure sensor functionality further comprises, in response to determining that the second pressure measurement is not an anomaly, performing a responsive action on the first individual pump.
29. The fluid system of claim 4, wherein determine whether an acceleration condition exists comprises sensing at least one of: a change flow demand in the system and a decrease in pressure in the system.
30. The fluid system of claim 1, wherein the controller samples the measured pressure from the pressure sensor at a rate greater than 1 hertz.
31. The fluid system of claim 1, wherein the aspects of the electrical signal are voltage, phase current, phase angle, or combinations thereof.
32. The fluid system of claim 1, wherein the electric motor is a brushless DC motor and the fluid pump is an axial piston type pump.
33. The fluid system of claim 1, wherein the fluid pump is a fixed displacement pump.
34. The fluid system in claim 1, wherein the electric motor is a brushless DC motor and the fluid pump is a radial piston type pump.
35. A fluid system comprising:
- a fluid pump having an output;
- an electric motor coupled to the fluid pump, the electric motor being adapted to operate the fluid pump in response to an electrical signal;
- a controller adapted to communicate the electrical signal to the electric motor, the controller including a lookup table having performance data related to the fluid pump and the electric motor, wherein the performance data from the lookup table is used by the controller to set aspects of the electrical signal communicated to the electric motor to achieve a desired system pressure generated by the fluid pump; and
- a pressure sensor in communication with the output that is adapted to communicate a sensed system pressure to the controller, the controller being adapted to update the lookup table based on a difference between the desired system pressure and the sensed system pressure to minimize variation between the sensed system pressure and the desired system pressure.
36. The fluid system of claim 35, wherein the lookup table establishes a relationship between motor current, motor speed, and the desired system pressure.
37. The fluid system of claim 36, further comprising a motor speed sensor for communicating a sensed motor speed to the controller, wherein the electrical signal includes a motor current command, and wherein the controller determines a value of the motor current command for achieving the desired system pressure from the lookup table based on the sensed motor speed.
38. The fluid system of claim 35, wherein the lookup table is updated based on sensed system pressure sensed while the fluid system is operating at steady state and the lookup table is not updated based on sensed system pressure sensed while system is operating in a transitory state.
39. A fluid system comprising:
- a fluid pump having an output;
- an electric motor coupled to the fluid pump, the electric motor being adapted to operate the pump in response to an electrical signal;
- a controller adapted to communicate the electrical signal to the electric motor, the controller including a lookup table having performance data related to the fluid pump and the electric motor, wherein the performance data from the lookup table is used by the controller to set aspects of the electrical signal communicated to the electric motor in order to achieve a desired attribute of the fluid pump; and
- a pressure sensor in communication with the output is adapted to communicate a sensed pressure to the controller, the controller adapted to create a modified lookup table to minimize variation in the output.
40. A fluid system comprising:
- at least two fluid pumps, each pump having an output;
- an electric motor coupled to each fluid pump, the electric motor being adapted to operate the pump in response to an electrical signal;
- at least one controller adapted to communicate the electrical signal to the electric motor, the controller including a lookup table having performance data related to the fluid pumps and the electric motors, wherein the performance data from the lookup table is used by the controller to set aspects of the electrical signal communicated to each electric motor in order to achieve a desired attribute of the fluid pumps; and
- a pressure sensor in communication with the outputs is adapted to communicate a sensed pressure to the controller, the controller adapted to create a modified lookup table to minimize variation in the outputs.
Type: Application
Filed: Oct 29, 2014
Publication Date: Sep 15, 2016
Inventors: Jeffrey David SKINNER, JR. (Madison, MS), Joshua Aaron SMITH (Ridgeland, MS)
Application Number: 15/033,324