Autonomic sensor device

Abstract

In embodiments herein, an autonomic sensor device with one or more sensors for sensing characteristic parameters of a hydraulic fluid of a hydraulic system is provided. The autonomic sensor device for use in a hydraulic system comprises one or more sensors arranged to measure operating parameters for the hydraulic system. The sensors are arranged to interact with a control unit. The system comprises at least one rotor provided with one or more permanent magnets. The rotor is arranged to rotate in the hydraulic flow in one flow path of the hydraulic system. The system further comprises one or more coils arranged to interact with the permanent magnets whereby electric power is harvested from the hydraulic flow. The autonomic sensor device is powered by the harvested electric power. The energy harvester is thus configured to harvest energy from the hydraulic circuit of the hydraulic system.

Description

[0001] AUTONOMIC SENSOR DEVICE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates generally to monitoring of hydraulic systems. More specifically, an autonomic sensor device with one or more sensors for sensing characteristic parameters of a hydraulic fluid of a hydraulic system is provided. The autonomic sensor device for use in a hydraulic system comprises one or more sensors arranged to measure operating parameters for the hydraulic system and is powered by harvested electric power.

[0004] BACKGROUND

[0005] Hydraulic systems often operate in harsh environmental conditions and thus, the hydraulic components can be prone to degradation and failures over time. It is therefore desirable to control the health and performance by monitoring various hydraulic components as well as the hydraulic system as a whole. Hydraulic systems include various hydraulic components such as pumps, motors, valves, actuators, hoses, etc., and a pressurized medium (liquid or gas) flows between the components. Such components are typically connected to each other and often operate in remote areas. The hydraulic components can be prone to degradation and failure over time. It is therefore desirable to monitor the health and performance of the various hydraulic components and / or the system as a whole.

[0006] Systems that are configured to monitor hydraulic system parameters and collect data are often used for diagnostic purposes. Diagnostic and condition monitoring for different hydraulic components may for example include, model-based diagnostics, data-driven diagnostics, and a hybrid between data-driven and model-based diagnostics.

[0007] Irrespective of which type of condition monitoring that may be used, it is central to as far as possible provide real-time measurements for various operative parameters of the hydraulic system, such as oil pressure, working temperature, oil flow etc. Sensors (sensing pressure, temperature, oil flow etc.) are provided in the hydraulic system to provide real-time measurements of various aspects of the hydraulic system to facilitate such diagnostic and condition monitoring.

[0008] However, integrating measurement devices such as sensors into hydraulic components or hydraulic systems may be very difficult. Hydraulic systems are often used in remote mobile settings in heavy duty environments. Therefore, powering of sensors and measurement equipment is often troublesome. Although some monitoring solutions been presented, problems often arise with electronic equipment and other sensitive components due to the often difficult operational environment. Further, parameters of interest are often related to the hydraulic circuits which comprises hydraulic oil set under high pressure which also makes them difficult to measure and monitor without risking failure or leakage of the hydraulic system.

[0009] There is a need of improvements when it comes to monitoring of hydraulic systems.

[0010] SUMMARY In accordance with embodiments herein, an autonomic sensor device with one or more sensors for sensing characteristic parameters of a hydraulic fluid of a hydraulic system is provided. The autonomic sensor device for use in a hydraulic system comprises one or more sensors arranged to measure operating parameters for the hydraulic system. The measured operating parameters may be available to external devices via wireless connection.

[0011] The sensors are arranged to interact with a control unit, and may be arranged outside the flow path of the hydraulic system. The system comprises at least one rotor provided with one or more permanent magnets. The rotor is arranged to rotate in the hydraulic flow in one flow path of the hydraulic system and may in embodiments be arranged to rotate axially in relation to the direction of the hydraulic flow path.

[0012] The system further comprises one or more coils arranged to interact with the permanent magnets whereby electric power is harvested from the hydraulic flow. The one or more coils may be arranged outside the flow path of the hydraulic system. The coils and / or the electronic equipment may be arranged on a flexible element at least partly embracing the rotor. The autonomic sensor device is powered by the harvested electric power. The energy harvester is configured to harvest energy from the hydraulic circuit of the hydraulic system. In embodiments, the autonomic sensor device may be arranged to analyze one or more electrical characteristic of the harvested power.

[0013] In embodiments, the autonomic sensor device may further comprise one or more power outlets powered by the harvested power. In embodiments, the autonomic sensor device may further comprise one or more outlets, and the measured operating parameters may be available to external devices via the one or more outlets.

[0014] In embodiments, the autonomic sensor device may further comprise electronic equipment arranged to communicate with the one or more sensors, and with the control unit, wherein the electronic equipment may be arranged outside the flow path of the hydraulic system.

[0015] In further embodiments, one or more of the sensors may be a wire strain gauge arranged to indirectly measure oil pressure in the hydraulic system. Further, one or more of the sensors may be a temperature sensor arranged to indirectly measure temperature of the oil in the hydraulic system. In embodiments, the autonomic sensor device may be arranged to monitor one or more of rotational speed, frequency and acceleration or retardation of the rotor. The autonomic sensor device may further be arranged to monitor one or more of position and orientation of the sensor device.

[0016] In embodiments, the autonomic sensor device may be mounted in a hose comprised in the hydraulic system. Alternatively, the autonomic sensor device may be mounted in a machine housing comprised in the hydraulic system. Still another alternative is that the autonomic sensor device may be integrated in the machine housing of the hydraulic system.

[0017] According to another aspect, a mining and / or construction rig comprising an autonomic sensor device is provided. According to yet another aspect, an attachment for use in a mining and / or construction rig comprising an autonomic sensor device is provided.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an overview over an autonomic sensor device.

[0019] Fig. 2 is a cross section showing the autonomic sensor device.

[0020] Fig. 3 is an exploded view of the autonomic sensor device.

[0021] Fig. 4 is an exploded view of the rotor in the autonomic sensor device. Fig. 5 is a cross sectional view showing the turbine of the rotor.

[0022] Fig. 6 and 7 shows a flexible element of the autonomic sensor system.

[0023] Fig. 8 shows an autonomic sensor system with the flexible element mounted.

[0024] Fig. 9 is an example of a hydraulic system in which the autonomic sensor device may be employed. Fig. 10 is an example of a hydraulic breaker in which the autonomic sensor device may be employed.

[0025] DETAILED DESCRIPTION

[0026] In general, the present disclosure relates to monitoring of hydraulic systems. Any type of system or machine employing a hydraulic circuit may be employed.

[0027] Embodiments herein will now be described more in detail with reference to the accompanying drawings.

[0028] Fig. 1 is an overview over an autonomic sensor device 1 according to embodiments herein. The autonomic sensor device 1 is shown in an assembled ready-to-use state. The autonomic sensor device 1 comprises an outer cover 2 arranged at least partly overlapping a first housing part 7. The autonomic sensor device 1 further comprises an inlet 9 and an outlet 10. The autonomic sensor device 1 is to be arranged in line with the hydraulic path of a hydraulic system. Hydraulic oil in the hydraulic system will flow into the inlet 9, through the device 1 , and out through the outlet 10. The autonomic sensor device 1 for use in the hydraulic system comprises one or more sensors arranged to measure operating parameters for the hydraulic system.

[0029] Fig. 2 is a cross sectional view showing the autonomic sensor device, and Fig. 3 is an exploded view of the autonomic sensor device. The autonomic sensor device 1 comprises at least one rotor 3 provided with one or more permanent magnets 4. The rotor 3 is arranged to rotate in the hydraulic flow in one flow path of the hydraulic system. The rotor 3 is provided with a turbine 11 arranged to be driven by the oil flow in the oil flow path whereby the rotor 3 is rotated. The rotor is in the exemplified embodiment arranged to rotate axially in relation to the direction of the hydraulic flow path. The rotor 3 is provided with blades 15 driven by the oil flow in the oil path whereby a rotational movement of the rotor 3 is achieved. The rotor 3 is thus arranged to rotate axially, and the outer periphery of the rotor 3 may be arranged to interact with bearings. The rotor 3 will be described more in detail later in relation to Fig. 4. The device further comprises one or more coils 5 (not shown in Fig. 3) arranged to interact with the permanent magnets 4 whereby electric power is harvested from the hydraulic flow. The autonomic sensor device 1 is powered by the harvested electric power. The rotor 3 and the coils 5 are thus arranged as an energy harvester configured to harvest energy from the hydraulic circuit of the hydraulic system. The sensors and the device 1 are arranged to interact with a control unit.

[0030] The control unit interacts with the sensors and may as well be powered at least in part by the device 1 , and may in some embodiments also be arranged to manage power from the device 1 for powering the control unit and the sensors, and also to perform diagnostics on the system based on data received from the sensors. Fig. 4 is an exploded view of the rotor in the autonomic sensor device. Inside the rotor 3 is the turbine 11 arranged. In the exemplified embodiment, the turbine and the rotor are attached to each other by us of snap fasteners. However, the rotor and the turbine may be attached to each other by any other suitable means, or may be made as a single, integrated unit. The rotor is provided with a plurality of permanent magnets 4. The magnets are arranged around the periphery of the rotor 3 and are resting on a flange 14 arranged on the rotor 3. The permanent magnet may be glued to the rotor, or may be embedded in the material of the rotor 3. The turbine 11 is provided with turbine blades arranged to set the turbine 11 and thus the rotor 3 in a rotational movement when an oil flow flows from the inlet through the device 1 and out through the outlet. Outside the rotor 3 is one or more bearings 13 arranged. In the example, ball bearings are used. It is to be noted that the rotor 3 does not have any axis with bearings to tortate around. Instead, the rotor rests against the outer bearings 13 during the rotational movements.

[0031] Fig. 5 is a cross sectional view showing the turbine 11 of the rotor 3 with the blades 15. The blades 15 are designed to achieve an efficient rotational movement of the rotor 3.

[0032] The autonomic sensor device 1 may be mounted in line with a hose comprised in the hydraulic system. The inlet 9 and the outlet 10 are mounted via coupling devices to the hose. For example, a threaded coupling may be used, or any other suitable type of coupling. Thereby, the oil flow in the hose may be used to power the device 1 by energy harvesting. Alternatively, the autonomic sensor device 1 may be mounted in a machine housing comprised in the hydraulic system. As yet another alternative, the autonomic sensor device 1 may be integrated in the machine housing of the hydraulic system. Irrespective of what type of mounting that is used, the device 1 uses the oil flow in the flow path in which it is mounted for energy harvesting.

[0033] Fig. 6 and 7 shows a flexible element 6 of the autonomic sensor device 1 . Fig. 8 shows an autonomic sensor device 1 with the flexible element 6 mounted. The flexible element 6 is arranged to hold the coils 5 of the device 1 , as well as the electronic equipment and circuits and also at least some sensors. As an example, an extending portion 17 may be used to hold a temperature sensor. When the flexible element 6 is mounted around the rotor 3 as shown in Fig. 8, the extending portion 17 will be arranged very close to the oil flowing inside the autonomic sensor device 1 in the flow path of the hydraulic system. Although the temperature of the hydraulic oil thus is measured indirectly, the measured temperature will be close to the true temperature of the oil, and by taken factors as ambient temperature, type of working mode of the hydraulic system, and historical data for operation into account a very accurate monitoring of the oil temperature of the hydraulic system will be provided. Further sensors may be arranged on or in the vicinity to the flexible element 6, for example sensors for measuring ambient parameters, like one or more sensors for measuring the ambient temperature or moisture.

[0034] The one or more sensors is in embodiments herein arranged outside the flow path of the hydraulic system to be monitored. By arranging the sensors and electronic equipment outside the oil flow path, the risk of leakage is minimized. Further, sensitive components are kept from the aggressive environment in or in the vicinity to the hydraulic oil. Thereby, the lifetime and the operational safety of the sensors are improved significantly. The one or more coils 5 are in embodiments herein also arranged outside the flow path of the hydraulic system. The autonomic sensor device 1 further comprises electronic equipment arranged to communicate with the one or more sensors, and with the control unit, wherein the electronic equipment may be arranged outside the flow path of the hydraulic system. As may be seen in Fig. 8, the coils and / or the electronic equipment is arranged on the flexible element 6 at least partly embracing the rotor 3. It is further to be noted that once the sensor device 1 is assembled, the outer cover 2 will serve as a mold. By filling the outer cover 2 with for example casting compound or glue, the sensitive equipment as sensors, coils and electronic circuits will be infused and thus protected from the environment.

[0035] Fig. 9 illustrates an exemplary rock drilling rig that may employ a sensor device 1 as disclosed herein. The rock drilling rig comprises at least one drilling unit which comprises a feed beam arranged in a drilling boom and a rock drill machine movable by means of a feed device with respect to the feed beam. The rock drilling rig can be operated locally or remote. The exemplary movable rock drilling rig 201 may be utilised e.g. in tunnel excavation. As can be seen in Fig. 9, the rock drilling rig 201 according to the disclosed example is provided with three booms 203-205, each of which is carrying a drilling machine 206-208 via feed beams 209-211. The disclosed rock drilling rig 201 may drill up to three holes at a time and each of the drilling machines may employ a sensor device 1 . The drilling process may be controlled remote or by an operator from a cabin 215. The drilling rig 201 is further arranged to communicate with a control system. The control system may be located remote or local. Drilling rigs of the disclosed kind may comprise more than one control unit, where each control unit, respectively, can be arranged to be responsible for different functions of the drilling rig.

[0036] The autonomic sensor device 1 may further be arranged to interact with one or more rechargeable batteries. Thereby, surplus harvested energy may be stored and used later, and the harvested energy can be used in a more efficient and flexible way.

[0037] The control unit receives data output by the sensor data, processes the data, and communicates with one or more external devices. Communication may be performed wireless, by cables, or by any other suitable means. External devices may be a data aggregating system or a separate system level control unit that will allow electrohydraulic components within the hydraulic system to be controlled or cycled in a specific manner such that system health can be evaluated. For instance, the control unit and / or external devices may be configured to compare a measured component or system parameter against a predefined component or system parameter that is representative of acceptable levels of performance and / or health. Such predefined parameters may typically be stored in a local or external memory.

[0038] The autonomic sensor device 1 may further be arranged to analyze one or more electrical characteristic of the harvested power. Electrical characteristics like induced voltage, working frequency, frequency analysis, rotational speed of the rotor 3, and acceleration or retardation, may be analyzed and used for diagnostic purposes regarding the status of the hydraulic system. For example, the presence of harmonics in the harvested power may indicate failure or disharmonic operation of the hydraulic system.

[0039] The measured data and the analyzed electrical characteristics may be stored and logged. By comparing new data with historical data, changes, trends and deviations can be detected and compared to expected data. Thereby, unexpected behavior can trigger an alert signal and errors emerging in the hydraulic system can be detected in an early stage. Examples are any unexpected changes or trends of the measured parameters, and also deviating electrical characteristics of the harvested, induced power. For example, upcoming harmonics may indicated un uneven oil flow and / or oil pressure / oil flow that may indicate failure for example an unexpected pressure / oil flow change, or a leakage in the hydraulic circuit, or a leakage in the accumulator of the hydraulic system. Such unexpected deviations can be detected and logged as a possible failure situation. Thereby, accurate and safe monitoring of the hydraulic system is provided.

[0040] In Fig. 10, a hydraulic breaker is showed. Hydraulic breakers are one example of a hydraulic attachment apparatus in which the autonomous sensor device may be employed. Hydraulic breakers comprises a back head and a front head holding a tool. The breaker further comprises a hydraulic accumulator. The operating pressure in the breaker may be operated by a control. The breaker transmit kinetic energy which is generated by a piston moving in a cylinder using hydraulic pressure. The kinetic energy is then converted to impact energy, and is used for breaking targets using the impact energy.

[0041] Hydraulic breakers are used for example for crushing mining stone at stone mining sites. When the temperature increases, the viscosity of the hydraulic oil decreases, and the flow rate of the hydraulic oil discharged through a valve regulating oil flow to the cylinders increases. The pressure acting on the valve is thus changed due to a pressure drop in the upper cylinder. When the pressure acting on the valve is changed, the valve may not move uniformly and regularly and the performance of the breaker will be disturbed.

[0042] Thus, a hydraulic breaker may have problem of being uniformly regularly operated when the viscosity and the flow rate are changed according to changes of the temperature of the hydraulic oil. By employing an autonomous sensor device 1 as disclosed herein, such changes in operation may easily be detected. For example, changes in the oil flow and / or in the oil temperature may easily be detected by the sensors and / or by the analysis of the electrical characteristics of the harvested energy.

[0043] The autonomic sensor device 1 may further comprise one or more power outlets powered by the harvested power. Any equipment needed on an operational site in connections to the hydraulic system may thus be powered. Thus, the need of external power supply or battery driven equipment will be reduced or eliminated. The harvested power may also be used for charging one or more rechargeable batteries that may be used when there is a higher demand on available power, or when the harvested energy for some reason is low. As an alternative to power outlets, the power may be transferred wirelessly, for example by magnetic coupling.

[0044] The autonomic sensor device 1 may further comprise one or more outlets, and the measured operating parameters may be available to external devices via the one or more outlets. As an example, a portable computer may be used, or a memory storage device. The measured operating parameters may as well be available to external devices via wireless connection.

[0045] The one or more of the sensors may be a wire strain gauge arranged to measure oil pressure in the hydraulic system. For example, a wire strain gauge may be arranged to indirectly measure oil pressure in the hydraulic system.

[0046] The one or more of the sensors may be a temperature sensor arranged to indirectly measure temperature of the oil in the hydraulic system. The one or more of the sensors may be measuring oil pressure. Further, the system 1 may be arranged to monitor one or more of position and orientation of the sensor device 1 . It is to be noted that any other suitable sensors may be used.

[0047] A mining and / or construction rig comprising an autonomic sensor device 1 is also provided, and still further an attachment for use in a mining and / or construction rig comprising an autonomic sensor device 1 is provided. According to another aspect, a method for monitoring a hydraulic system is provided. An autonomic sensor device 1 is arranged in line with an oil flow path of the hydraulic system to be monitored, and comprises one or more sensors, at least one rotor 3 provided with one or more permanent magnets 4. The rotor 3 is arranged to rotate in the hydraulic flow in the flow path of said hydraulic system. One or more coils 5 are arranged to interact with the permanent magnets 4. The method comprises harvesting electric power from the hydraulic flow by use of electric power induced in the coils 5 when the permanent magnets interacts with the coils 5 when the rotor 3 rotates, powering sensors, electronic circuits and components comprised in or arranged to interact with the autonomic sensor device 1 with the harvested electric power, -measuring operating parameters of the hydraulic system by use of said one or more sensors, analyzing rotational speed, frequency, acceleration or retardation, and other electrical data of the induced power, calculating a health status value for the hydraulic system based on historical data, present measured operating parameters and present analyzed electrical data of the induced power, and if a deviant health status value of the hydraulic system is calculated, generating an alert signal.

[0048] The foregoing disclosure is not intended to limit the present invention to the precise forms or particular fields of use disclosed. It is contemplated that various alternate embodiments and / or modifications to the present invention, whether explicitly described or implied herein, are possible in light of the disclosure. Accordingly, the scope of the invention is defined only by the claims.

Claims

CLAIMS1 . Autonomic sensor device (1 ) for use in a hydraulic system, the autonomic sensor device (1 ) comprising: - one or more sensors arranged to measure operating parameters for said hydraulic system, wherein said sensors are arranged to interact with a control unit,- at least one rotor (3) provided with one or more permanent magnets (4), wherein said rotor (3) is arranged to rotate in the hydraulic flow in one flow path of said hydraulic system, and- one or more coils (5) arranged to interact with said permanent magnets (4) whereby electric power is harvested from the hydraulic flow,- wherein said autonomic sensor device (1 ) is powered by said harvested electric power.

2. Autonomic sensor device (1 ) according to claim 1 , wherein said rotor is arranged to rotate axially in relation to the direction of the hydraulic flow path.

3. Autonomic sensor device (1 ) according to any of the preceding claims, wherein said one or more sensors are arranged outside said flow path of the hydraulic system.

4. Autonomic sensor device (1 ) according to any of the preceding claims, wherein one or more electrical characteristic of the harvested power is analyzed.

5. Autonomic sensor device (1 ) according to any of the preceding claims, further comprising one or more power outlets powered by said harvested power.

6. Autonomic sensor device (1 ) according to any of the preceding claims, further comprising one or more outlets, and wherein said measured operating parameters are available to external devices via said one or more outlets.

7. Autonomic sensor device (1 ) according to any of the preceding claims, wherein said measured operating parameters are available to external devices via wireless connection.

8. Autonomic sensor device (1 ) according to any of the preceding claims, wherein said one or more coils (5) are arranged outside said flow path of the hydraulic system.

9. Autonomic sensor device (1 ) according to any of the preceding claims, further comprising electronic equipment arranged to communicate with said one or more sensors, and with said control unit, wherein said electronic equipment is arranged outside said flow path of the hydraulic system.

10. Autonomic sensor device (1 ) according to any of the preceding claims, wherein said coils and / or said electronic equipment is arranged on a flexible element ( ) at least partly embracing said rotor (3).

11. Autonomic sensor device (1 ) according to any of the preceding claims, wherein one or more of the sensors is a temperature sensor arranged to indirectly measure temperature of the oil in the hydraulic system.

12. Autonomic sensor device (1 ) according to any of the preceding claims, wherein one or more of the sensors are indirectly measuring oil pressure.

13. Autonomic sensor device (1 ) according to any of the preceding claims, further arranged to analyze rotational speed, frequency, acceleration or retardation, and other electrical data of the induced power.

14. Autonomic sensor device (1 ) according to any of the preceding claims, wherein one or more of position and orientation of the sensor device (1 ) is monitored.

15. Autonomic sensor device (1 ) according to any of the preceding claims, wherein the autonomic sensor device (1 ) is mounted in line with a hose comprised in the hydraulic system.

16. Autonomic sensor device (1 ) according to any of the preceding claims, wherein the autonomic sensor device (1 ) is mounted in a machine housing comprised in the hydraulic system.

17. Autonomic sensor device (1 ) according to any of the preceding claims, wherein the autonomic sensor device (1 ) is integrated in the machine housing of the hydraulic system.

18. Mining and / or construction rig comprising an autonomic sensor device (1 ) according to any of claims 1 -17.

19. Hydraulic attachment for use in a mining and / or construction rig, wherein said attachment comprises an autonomic sensor device (1 ) according to any of claims 1 -17.

20. A method for monitoring a hydraulic system, by use of an autonomic sensor device (1 ) arranged in line with an oil flow path of the hydraulic system to be monitored, wherein the autonomic sensor device (1 ) comprises one or more sensors, at least one rotor (3) provided with one or more permanent magnets (4) and being arranged to rotate in the hydraulic flow in the flow path of said hydraulic system, one or more coils (5) arranged to interact with said permanent magnets (4), the method comprises- harvesting electric power from the hydraulic flow by use of electric power induced in the coils (5) when the permanent magnets interacts with the coils(5) when the rotor (3) rotates,- powering sensors, electronic circuits and components comprised in or arranged to interact with the autonomic sensor device (1 ) with the harvested electric power,- measuring operating parameters of the hydraulic system by use of said one or more sensors,- analyzing rotational speed, frequency, acceleration or retardation, and other electrical data of the induced power, - calculating a health status value for the hydraulic system based on historical data, present measured operating parameters and present analyzed electrical data of the induced power, and- if a deviant health status value of the hydraulic system is calculated, generating an alert signal.

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