Patent Application
20240271394
The present disclosure relates to a diagnostic system for determining a performance status of a hydraulic system driven by an electric motor. The present disclosure also relates to an electric work machine incorporating such a diagnostic system. The present disclosure further relates to a method of determining a performance status of a hydraulic system driven by an electric motor.
Construction machines such as hydraulic excavators which are used in excavating and demolition operations and which employ a diesel engine to drive a hydraulic pump or set of hydraulic pumps have been in use for many years. In such machines hydraulic fluid is pumped to various hydraulic actuators in order to operate work tools, such as a boom and bucket.
Electric hydraulic construction machines have been replacing previous models powered by diesel engines in order to reduce emissions. Such electric hydraulic construction/off-highway equipment and machines include, for example, excavators, telehandlers, forklifts, etc., with electrohydraulic powertrain architecture. Such machines can be collectively referred to as electrohydraulic work machines.
Various problems can arise in hydraulic systems which affect the performance of the system and can damage parts of the systems. Such problems can include particulate contamination of the hydraulic fluid, air in the hydraulic fluid, clogged filters, leaks in the hydraulic circuit, misalignment of parts such as couplings, damaged or worn parts, etc. It would be desirable to be able to provide a system for identifying and predicting faults and servicing needs of a hydraulic system.
According to one aspect of the present disclosure there is provided a diagnostic system for determining a performance status of a hydraulic system of an electric work machine, the hydraulic system having a first hydraulic pump driven by an electric motor for pumping hydraulic fluid within the hydraulic system, the system comprising:
The invention provides a diagnostic tool to identify failures or maintenance requirements in the hydraulic system by monitoring the electric motor performance. This allows issues to be identified early on. The hydraulic system may comprise a hydraulic pump, hydraulic fluid tank, hydraulic fluid cooler, control valves and hydraulic actuators. The first operating variable of the electric motor in some examples may be compared with a predetermined operational behavior which may comprise a predetermined threshold value for said operating variables. The hydraulic system in some examples may have at least one work device that is hydraulically powered by the hydraulic system. The hydraulic diagnostic module may include at least one processor. The hydraulic diagnostic module may be incorporated into other control units or processors of the electric work machine, such as a Vehicle Control Unit (VCU) or System Control Module (SCM).
In some examples the hydraulic diagnostic module is further configured to receive a signal corresponding to a first sensed temperature value sensed by a temperature sensor configured to sense a temperature of the hydraulic fluid, the hydraulic diagnostic module being configured to compare the first operating variable of the electric motor with a predetermined operational behavior, and wherein the predetermined operational behavior used in the comparison may differ depending on said sensed temperature value.
The viscosity of the hydraulic fluid may vary depending on the temperature of the hydraulic fluid, therefore the first operating variable of the electric motor is compared with a predetermined operational behavior for the given temperature value that has been sensed.
In some examples, the hydraulic diagnostic module is configured to determine the performance status of the hydraulic system without receiving any input from sensors which sense characteristics of the hydraulic system itself, apart from optionally receiving sensed temperature values of the hydraulic fluid.
The diagnostic system does not include any sensors for sensing characteristics of the hydraulic system, except in certain embodiments a temperature sensor to sense the temperature of the hydraulic fluid.
In some examples, the first operating variable of the electric motor comprises a variable selected from the following: motor speed, motor torque, and power drawn by the hydraulic pump.
In some examples, the performance status of the hydraulic system that may be derived from the comparison comprises a fault condition or a maintenance requirement.
A fault condition could be an indication of any sort of abnormality detected in the hydraulic system which may need inspection or further monitoring. A maintenance requirement may be any service action that needs to take place to keep the hydraulic system running in good order.
In some examples, the fault condition of the hydraulic system that may be derived from the comparison comprises one or more of the following:
In some examples, the maintenance requirement of the hydraulic system that may be derived from the comparison comprises one or more of the following:
The maintenance requirement of the hydraulic system that may be derived from the comparison may comprise an indication that any serviceable item requires replacing. A maintenance requirement of the hydraulic system that may be derived from the comparison may also be an indication that a non-serviceable component requires repair or replacement.
In some examples, the maintenance requirement comprises a predicted maintenance requirement derived from the comparison of the first operating variable of the electric motor with a predetermined operational behavior.
A predicted maintenance requirement may be a prediction that a maintenance requirement will be due at a certain point in the future.
In some examples, the electric motor has a first idling speed, said first operating variable being motor speed and the predetermined operational behavior being the electric motor spinning up to reach its first idling speed within a predetermined time, wherein the hydraulic diagnostic module derives a fault condition as the performance status of the hydraulic system if the electric motor fails to reach its first idling speed within said predetermined time.
The first idling speed of the electric motor is a speed at which the rotor of the electric motor rotates when the hydraulic system is not performing work. The first idling speed may be a first preset idling speed set by an operator. The fault condition may be a misalignment condition indicating misalignment of any parts within the hydraulic system, or it may be a hydraulic pump jam condition indicating a jam in the hydraulic system, such as due to improper lubrication, or a blockage condition indicating a blockage in the hydraulic system, such as a blockage in a suction hose. In certain embodiments, the operational behavior is spinning up of the electric motor from a non-rotating condition to reach its first idling speed. The hydraulic diagnostic module suitably monitors the motor as it is spinning up to the first idling speed.
In some examples, the electric motor has a first idling speed, the first operating variable being power drawn by the hydraulic pump during spinning up of the electric motor to reach its first idling speed and the predetermined operational behavior being a predetermined power drawing activity of the electric motor during spinning up of the electric motor to reach its first idling speed, wherein the hydraulic diagnostic module derives a fault condition as the performance status of the hydraulic system if power drawn by the hydraulic pump deviates from the predetermined power drawing activity.
In some examples, the predetermined operational behavior comprises the power drawn by the hydraulic pump during spinning up of the electric motor to reach its first idling speed being within a predetermined range, the hydraulic diagnostic module deriving a fault condition as the performance status of the hydraulic system if power drawn by the hydraulic pump is outside of the predetermined range.
If it is detected that the power drawn by the hydraulic pump as it spins up to reach its first idling speed is not stable, the fault condition derived could be a trapped air condition indicating air entrapped within at least part of the hydraulic system. The system may be configured to output an alert if any fault condition is detected. The performance status derived from detecting a trapped air condition may be an advisory condition which does not trigger a fault status to the operator upon initial detection. The hydraulic diagnostic module may be configured such that an output alert is only triggered if a fault condition of a trapped air condition is detected more than a predetermined number of times. For example, if the trapped air condition is derived by more than a threshold number of times in succession, the system may output an alert indicating an air trapped condition.
In some examples, the electric motor has a first idling speed, the first operating variable comprising motor torque required during spinning up of the electric motor to reach its first idling speed and the predetermined operational behavior comprising the electric motor spinning up to reach its first idling speed at a threshold motor torque, wherein the hydraulic diagnostic module derives a leak condition indicating leakage within at least part of the hydraulic system as the performance status of the hydraulic system if the motor torque required during spinning up is less than the predetermined threshold motor torque.
The motor torque value in some examples may be compared to the threshold value at the corresponding hydraulic fluid temperature, so as to take account of the impact of differing fluid viscosity depending on the fluid temperature.
In some examples, the electric motor has a first idling speed, the first operating variable comprising motor torque required during spinning up of the electric motor to reach its first idling speed and the predetermined operational behavior comprising the electric motor spinning up to reach its first idling speed at a threshold motor torque, wherein the hydraulic diagnostic module derives a hydraulic pump jam as the performance status of the hydraulic system if the motor torque is more than the predetermined threshold motor torque.
The motor torque value in some examples may be compared to the threshold value at the corresponding hydraulic fluid temperature, so as to take account of the impact of differing fluid viscosity depending on the fluid temperature.
In some examples, the first operating variable comprises torque of the electric motor and the hydraulic diagnostic module is further configured to record the motor torque and sensed temperature value of the hydraulic fluid such that motor torque and sensed temperature value at a plurality of instances over time can be recorded as recorded system data, said predetermined operational behavior being said recorded system data, the hydraulic diagnostic module being configured to derive a maintenance requirement status if a change in motor performance or an acceleration in change in motor performance is derived by comparing torque with the recorded system data.
By means of comparing the motor torque with recorded system data relating to recorded motor torque at previous instances, the system can detect changes in performance of the hydraulic system and identify whether any serviceable items need replacing, such as hydraulic filter or hydraulic fluid. The motor torque and sensed temperature value may be recorded as the electric motor is spinning up to its first idling speed. Alternatively, the motor torque and sensed temperature may be recorded when the electric motor is operating at its set first idling speed. The hydraulic diagnostic module in some examples may have a memory for recording inputs to the hydraulic diagnostic module. The recorded system data may store motor torque and sensed temperature values over the lifetime of the electrohydraulic system so that an instant torque value can be compared against lifetime values at the corresponding hydraulic fluid temperature to detect health of non-serviceable items such as the electric motor, hydraulic pump, hydraulic valves, and hydraulic manifold.
In some examples, the first operating variable comprises motor torque and the hydraulic diagnostic module is further configured to record the motor torque and sensed temperature value of the hydraulic fluid at a plurality of instances over time as recorded system data, said predetermined operational behavior being a degradation model comprising data indicative of expected motor behavior, the hydraulic diagnostic module being configured to derive a maintenance requirement status based on comparison of the recorded system data with the degradation model. By comparing electric motor behavior with the degradation model, acceleration of degradation of the hydraulic system can be detected.
The degradation model may comprise predicted data corresponding to a plurality of different service intervals for the hydraulic system, the hydraulic diagnostic module being configured to store one or more parameters regarding servicing events carried out on the hydraulic system such that the operating variables of the electric motor can be compared with values within the degradation model for the corresponding service interval. The degradation model may also comprise data indicative of expected motor behavior over the lifetime of non-serviceable items associated with the system so that health of non-serviceable items such as the electric motor, hydraulic pump, hydraulic valves, and hydraulic manifold can be monitored. The data in the degradation model can be updated based on data recorded from other electrohydraulic systems of the same kind, said data being updated telematically.
In some examples, the system further comprises an output device for alerting an operator to a derived performance status.
In some embodiments the output device is a display which can be used to display information regarding the performance status. However, the output device may be an audio alert device or a device for transmitting data regarding the performance status to another device.
In some examples, the hydraulic system has a key-on mode wherein the electric motor is spinning up to reach a first idling speed, the diagnostic system being configured to determine the performance status of the hydraulic system during the key-on mode.
In some examples, the hydraulic system has a diagnostic mode wherein the diagnostic system is configured to determine the performance status of the hydraulic system if the diagnostic system is converted to diagnostic mode.
The diagnostic system may be configured such that if the electric motor is not performing any work, an operator can set the diagnostic system to said diagnostic mode, which triggers the system to run the hydraulic diagnostic module to determine a performance status of a hydraulic system. The system may be configured such that it automatically enters the diagnostic mode if it is detected that the electric motor is not performing any work, which triggers the diagnostic system to operate the hydraulic diagnostic module to determine a performance status of a hydraulic system.
According to one aspect of the present disclosure there is provided an electric work machine having at least one work device that is hydraulically powered by a hydraulic system having a first hydraulic pump driven by an electric motor for pumping hydraulic fluid within the hydraulic system, the electric work machine comprising a diagnostic system for determining a performance status of the hydraulic system the diagnostic system comprising:
a hydraulic diagnostic module configured to receive a first operating variable of the electric motor, the hydraulic diagnostic module further being configured to compare the first operating variable of the electric motor with a predetermined operational behavior and to derive a performance status of the hydraulic system based on the comparison.
The hydraulic diagnostic module of the electric work machine may be configured according to any aspect of the disclosure as set out above.
According to one aspect of the present disclosure there is provided a method for determining a performance status of a hydraulic system of an electric work machine, the hydraulic system having a first hydraulic pump, driven by an electric motor, for pumping hydraulic fluid within the hydraulic system, the method comprising
The method may determine a performance status of a hydraulic system in any of the ways as set out above in relation to the diagnostic system as set out above.
Features of the present disclosure will now be described, purely by way of example, with reference to the accompanying drawings, in which:
The present embodiments represent currently the best ways known to the applicant of putting the invention into practice. But they are not the only ways in which this can be achieved. They are illustrated, and they will now be described, by way of example only.
Referring now to the drawings, wherein like reference numerals refer to like features throughout several figures,
The hydraulic system 10 further includes a plurality of primary control valves 16 that control the flow of hydraulic fluid supplied from the hydraulic pump 14 to the plurality of hydraulic actuators 18. The hydraulic system 10 also includes a heat exchanger comprising a hydraulic fluid cooler 19 for exchanging heat between hydraulic fluid of the hydraulic system and the air. An electric motor 20 drives the hydraulic pump 14 so that the hydraulic system 10 can power the actuators 18 for controlling the machine functions. Some electrohydraulic systems, such as that of
Referring to
Referring to
In the embodiment of
The hydraulic diagnostic module 110 receives inputs from the electric motor 20 relating to performance of the electric motor. In certain steps the hydraulic diagnostic module 110 receives the motor speed as an input. In other steps, as will be described, the hydraulic diagnostic module 110 receives the motor torque as an input. The hydraulic diagnostic module 110 may furthermore receive the power drawn by the hydraulic pump as an input, which can be inferred from the product of the motor speed and motor torque. The motor speed and motor torque can be inferred from feedback from the motor itself (taking account of the motor voltage and current). Alternatively, the electric motor may include motor sensors to sense the motor speed and/or torque and to output signals relating to the speed and/or torque to the hydraulic diagnostic module 110.
In step 206 the hydraulic diagnostic module 110 receives the electric motor speed as an input and compares it with the preset idling speed of the motor. The hydraulic diagnostic module 110 is configured such that if the motor is unable to reach the preset idling speed of the motor within a predetermined time, the module derives a fault condition (e.g., step 208) as its performance status of the hydraulic system. The motor being unable to reach its preset idling speed may be indicative of a major fault within the hydraulic system, such as a misalignment condition caused by misalignment of parts within the hydraulic system.
The hydraulic diagnostic module 110 may be configured to output an alert if a fault condition is detected or if certain fault conditions are detected, and the alert may indicate the type of fault condition detected. For example, the hydraulic diagnostic module 110 may transmit an alert signal to an output device such as display 120 or an audio alert device. Therefore, if a fault condition (step 208) is derived after any of the diagnostic steps in the process of
If the motor reaches its preset idling speed, the hydraulic diagnostic module 110 continues to perform further analyses on the motor performance to diagnostically assess the health of the hydraulic system. At step 210 the hydraulic diagnostic module 110 receives the power drawn over time by the hydraulic pump as the motor spins up to its preset idling speed, as an input and compares it with an expected power draw range. If the power drawn by the pump is outside a predetermined range, the module derives a fault condition 208 as its performance status of the hydraulic system. Abnormal variation or fluctuation in the power to reach the preset idling speed is indicative of a trapped air condition wherein there is air trapped within at least part of the hydraulic system. Air trapped in the system can cause cavitation (formation of bubbles in the hydraulic fluid), which can decrease the efficiency of the hydraulic system and cause fatigue and failure in components of the hydraulic system. Therefore, it is important to identify such a problem early so that steps to fix the problem can be taken, such as bleeding air from the system.
Hydraulic fluid will typically contain a small amount of air suspended or dissolved in the fluid. However, it is important to detect whether there is excessive air in the system that is not dissipating naturally, as excessive air can cause damage to the hydraulic system components and lead to poor operation of the work tools that are driven by the hydraulic system. The hydraulic diagnostic module 110 can be configured so that a fault condition 208 and/or alert is only triggered if a trapped air condition is identified more than a predetermined number of times. In this way, if the diagnostic process identifies trapped air in the system repeatedly, each time the hydraulic diagnostic module runs the diagnostic process, a fault condition is triggered so that an operator can troubleshoot the problem.
Another diagnostic process that the hydraulic diagnostic module 110 can perform if the electric motor reaches its first preset idling speed is at step 212 of
The hydraulic diagnostic module 110 in some examples may be configured such that the predetermined threshold torque value selected for step 212 can vary depending on certain factors. For example, the predetermined leak torque value selected for the comparison carried out by the hydraulic diagnostic module 110 may differ depending on the characteristics of the particular pump of the hydraulic system.
Furthermore, the predetermined threshold torque value used in the comparison carried out by the hydraulic diagnostic module 110 may vary depending on the sensed hydraulic fluid temperature. The hydraulic diagnostic module 110 can receive as an input a first sensed temperature value corresponding to the temperature of the hydraulic fluid as sensed by a temperature sensor 22, so that the hydraulic fluid temperature can be taken into account when assessing the motor torque value required to reach the electric motor's first preset idling speed. The viscosity of the hydraulic fluid will vary depending on the temperature of the hydraulic fluid. Therefore, by means of the system using a predetermined threshold torque value which corresponds to the hydraulic fluid temperature, the accuracy of the system in identifying faults can be greater than otherwise. The temperature sensor 22 in some examples may be located at the hydraulic tank (as shown in
During diagnostic development of the hydraulic diagnostic module 110, data gathering is carried out on sample electrohydraulic systems, including recording of electric motor torque and hydraulic fluid temperature in order to establish a correlation between the torque and hydraulic fluid temperature for the particular system. This correlation is used when setting the predetermined torque values for step 212 and other steps of the diagnostic process 200.
Another diagnostic process that the hydraulic diagnostic module 110 can perform if the electric motor reaches its first preset idling speed is at step 214 of
As with step 212, the hydraulic diagnostic module 110 may be configured such that the predetermined threshold torque value selected for step 214 can vary depending on certain factors. For example, the predetermined jam torque value selected for the comparison carried out by the hydraulic diagnostic module 110 may differ depending on the characteristics of the particular pump of the hydraulic system. Furthermore, the predetermined jam torque value used in the comparison at step 214 will depend on the hydraulic fluid temperature, based on the sensed hydraulic fluid temperature sensed by temperature sensor 22. In this way the system can take account of the hydraulic fluid temperature to improve the accuracy of the detection of jams in the hydraulics.
Another diagnostic process that the hydraulic diagnostic module 110 can perform if the electric motor reaches its first preset idling speed is at steps 220 to 228 of
At step 222 the instant motor torque is compared by the hydraulic diagnostic module 110 with a stored degradation model comprising data indicative of expected motor behavior so as to derive any signs of premature service events. The degradation model may be stored by the memory of the hydraulic diagnostic module 110 or accessed from an external memory which is accessible by the hydraulic diagnostic module 110 wirelessly or by network connection. The degradation model in some examples may comprise predicted data corresponding to a plurality of service intervals for the hydraulic system, and the hydraulic diagnostic module 110 in some examples may be configured to receive, as an input status, data regarding the instant service interval of the hydraulic system so as to correlate with the relevant data in the degradation table. The degradation model will have been previously devised by observing the electric motor torque and hydraulic fluid temperature as electrohydraulic systems degrade through use in order to determine threshold torque values corresponding to points at which it is recommended to take certain servicing actions such as replacement of serviceable items including hydraulic fluid and the hydraulic filter. For example, a threshold torque value for replacing the hydraulic fluid and a threshold torque value for replacing the hydraulic filter can be identified for the degradation model. This is useful as over time, the hydraulic fluid can become contaminated by debris such as wear debris, which can cause damage to components of the hydraulic system such as the pump. Clogged filters can release contaminants into the hydraulic system. Therefore, identifying premature degradation is very useful so that serviceable items can be replaced before causing damage to other components of the hydraulic system.
At step 224, if comparison of the recorded electric motor torque at particular hydraulic fluid temperature with the degradation model by the hydraulic diagnostic module 110 identifies that there is any acceleration of degradation, then the hydraulic diagnostic module 110 derives a maintenance requirement status as its performance status. At step 226, the hydraulic diagnostic module 110 is configured to output an alert if a maintenance requirement status is derived, which in this embodiment comprises output of an alert via a display, for example a user display in the electric work machine. At step 226, in the present embodiment the alert comprises update of a service schedule which can be displayed on the user display. If comparison of the recorded electric motor torque at particular hydraulic fluid temperature with the degradation model by the hydraulic diagnostic module 110 identifies no acceleration of degradation, then the diagnostic process ends (step 228). An identification of acceleration of degradation of motor performance may be an identification that the motor performance is deteriorating more quickly than expected as per the degradation model.
In an alternative diagnostic process 200A shown in
The diagnostic process 200A of
At step 224, if comparison of the recorded electric motor torque at particular hydraulic fluid temperature with the degradation model by the hydraulic diagnostic module 110 identifies that there is acceleration of degradation, then instead of simply updating the expected service schedule as in diagnostic process 200, in diagnostic process 200A one or more further decision steps are included as shown in
At step 232, if the determination of whether the hydraulic system underwent a service event since the last time the diagnostic process 200A was run is non-affirmative, at step 226 the expected service schedule is updated and the diagnostic process then ends (step 228). The service schedule update may be visible as an alert on the user display. In this way, the next scheduled service event can be brought forward, if acceleration of degradation is identified and no recent service event has taken place.
If the determination at step 232 is affirmative (i.e. acceleration of degradation has been detected and a service event took place since the last time the diagnostic process 200A was run), at step 234 the hydraulic diagnostic module 110 compares the current motor performance with that before the service event to determine whether the motor performance is similar to that before the service event (i.e. whether the level of degradation is similar to that before the service event). For example, the hydraulic diagnostic module 110 may assess the degradation and assign a measured degradation level, and if the measured degradation level is the same or below the degradation level measured before the last service event, the level of degradation would be determined as similar. The level of degradation could alternatively be determined as similar if it is within a predetermined range around the degradation level measured before the last service. If the motor performance is assessed as similar to that before the service event, at step 236, the hydraulic diagnostic module 110 derives a performance status, specifically a maintenance requirement status indicating that there is potential degradation of a non-serviceable component of the electrohydraulic system. Such a status may warn the operator of degradation of a non-serviceable item such as the electric motor, hydraulic pump, hydraulic valves, or hydraulic manifold. If similar degradation is detected shortly after a service event as compared to before the service event, even after replacement of serviceable items during the service event, then it is likely that the deterioration in performance is due to a problem with a non-serviceable item. At step 236, in the present embodiment the alert comprises a display warning of potential non-serviceable component degradation on the user display. The operator can therefore arrange an inspection of the non-serviceable components of the electrohydraulic system. The diagnostic process then ends (step 228).
If the determination at step 234 is non-affirmative (i.e. the motor performance is not determined to be similar to that before the service event), at step 238 the hydraulic diagnostic module 110 determines whether the motor performance has worsened compared to before the service event. For example, the hydraulic diagnostic module 110 may assess the degradation and assign a measured degradation level, and if the measured degradation level is greater than the degradation level measured before the last service event, the level of degradation would be determined as worsened. If the motor performance is assessed as worse compared to that before the service event, at step 240, the hydraulic diagnostic module 110 derives a condition of a warning of potential incorrect hydraulic fluid in the tank. Such a fault condition may also be attributed to other incorrect serviceable items having been introduced into the electrohydraulic system, such as an incorrect filter. If after a service event, the degradation assessed is similar to that before the service, the degradation can be fully attributed to the non-serviceable components. However, if the degradation is worsened, it can be attributed to incorrect hydraulic fluid or other incorrect serviceable items having been introduced during the service. When the fault condition at step 240 is derived by the system, the hydraulic diagnostic module 110 is configured to output an alert, which in this embodiment comprises a display warning of potential incorrect hydraulic fluid in the tank. The operator can therefore arrange testing and/or replacement of the hydraulic fluid. The diagnostic process then ends (step 228).
If the determination at step 238 is non-affirmative (i.e. the motor performance is not determined to be worse compared to that before the service event), at step 226 the expected service schedule is updated and the diagnostic process then ends (step 228). The service schedule update may be visible as an alert on the user display. In this way, the next scheduled service event can be brought forward, if acceleration of degradation is identified even though a service event has recently taken place.
At step 232, instead of determining whether the hydraulic system underwent a service event since the last time the diagnostic process 200A was run, the hydraulic diagnostic module 110 may determine whether the number of times the diagnostic process 200A was run since the last service event is below a threshold number, and if non-affirmative the process advances to step 226 and if affirmative, advances to step 234. Alternatively, at step 232, the hydraulic diagnostic module 110 may determine whether the time elapsed since the last service event is less than a threshold level, and if non-affirmative the process advances to step 226 and if affirmative, advances to step 234. In this way the system can seek to detect any degradation not attributable to serviceable items, i.e. if poor motor performance is still detected after a recent service event.
The data in the degradation model can be created and/or improved over time using data recorded from other electrohydraulic systems of the same kind. Said data may be gathered from a plurality of electrohydraulic systems telematically. A degradation model stored in the memory of a hydraulic diagnostic module 110 can be updated telematically with the data gathered from multiple other systems. The data gathered from a plurality of electrohydraulic systems can be used in machine learning systems in order to improve the diagnostic process 200. In this way, the accuracy of the degradation model can be improved as more data is collated.
The degradation model can also comprise data indicative of expected motor behavior over the lifetime of non-serviceable items associated with the system so that health of non-serviceable items such as the electric motor, hydraulic pump, hydraulic valves, and hydraulic manifold can be monitored. In this way, any acceleration in degradation of non-serviceable items can be identified so that the relevant non-serviceable item can be replaced before it becomes too degraded to operate. A degradation model incorporating data relevant to the health of non-serviceable components can be devised in a similar way to that for monitoring serviceable components, for example by observing the electric motor torque and hydraulic fluid temperature of a plurality of machines over their lifetime as the non-serviceable components degrade in order to determine threshold torque values corresponding to points at which it is recommended to take certain servicing actions such as replacement of a particular non-serviceable component.
Steps 220 onwards in some examples may only be carried out if no fault condition 208 is triggered by any of steps 206 to 216. The hydraulic diagnostic module 110 may be configured to carry out steps 220 onwards independently of any of steps 206 to 216.
As mentioned above, in the embodiment of
An example of a user induced diagnostic process 300 is shown in
The diagnostic process 200, 200A, 300 can end (step 228) after any point in the diagnostic process and it is not necessary for the diagnostic process to include all of the decision points of any of the particular processes 200, 200A, 300 (e.g. step 206, 210, 212, 214, 216, 224, etc.), and it may include one or only some of those decision points.
Steps 210, 212, 214, and/or 220 of the diagnostic process 200, 200A can be run simultaneously by the hydraulic diagnostic module 110. Steps 210, 212, 214 and 220 can be run sequentially in any order. Any of steps 206 to 226 of diagnostic process 200 or steps 206 to 240 of diagnostic process 200A, 300 can be left out of the diagnostic process.
An algorithm circuit for carrying out the diagnostic process 200, 200A, 300 may be provided. The algorithm circuit may be embodied as machine or computer-readable media that is executable by a processor of the hydraulic diagnostic module 110. The computer readable program code may be executed on one processor or multiple processors. In the latter scenario, the remote processors may be connected to each other through any type of network. In another configuration, the algorithm circuit is embodied as a hardware unit of the hydraulic diagnostic module 110. The algorithm circuit may take the form of one or more circuits.
The present diagnostic system and method for determining a performance status of a hydraulic system can be used to detect faults such as air, leaks, jams or blocks in the hydraulic system without any additional sensors (i.e. with use of only the hydraulic fluid temperature sensor for some optional parts of the diagnostic process, which is already present in a standard hydraulic system). If the hydraulic system does not have its own hydraulic fluid temperature sensor, a hydraulic fluid temperature sensor can be added to the hydraulic system and configured such that signals relating to hydraulic fluid temperature can be received by the hydraulic diagnostic module 110 as an input. The diagnostic system and method also allows the prediction of service/maintenance events on the hydraulic system (for example hydraulic fluid change, filter change, etc.). The present invention provides a way to identify faults such as leaks or blocks in the hydraulic system early on. It also allows for serviceable components of the hydraulic system to only be changed when needed, meaning that the hydraulic fluid or filter are not changed too early, avoiding unnecessary expense. It also avoids such serviceable components being replaced too late, which may damage other components of the hydraulic system. The invention is able to detect drift in the current required by the electric motor over time to help identify wear and potential failures. And the invention can diagnose potential wrong hydraulic fluid type used during servicing of the hydraulic system.
It will be appreciated that embodiments of the present disclosure have been described above by way of example only, and modifications in detail will be apparent to the skilled person within the scope of the appended claims. Embodiments of the disclosure have been described above by way of example only. Features of one embodiment may be used with any other embodiment. Other modifications will be apparent to the skilled person within the scope of the claims.
In particular and in regard to the various functions performed by the above described components, devices, systems and the like, the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., a functional equivalent), even though not structurally equivalent to the disclosed structure, which performs the function in the herein illustrated exemplary aspects of the claimed subject matter.
The present application claims priority to U.S. Provisional Patent Application No. 63/445,393, filed Feb. 14, 2023, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63445393 | Feb 2023 | US |
