CA3022574A1

CA3022574A1 - Method for testing operation of parking brake systems of machines

Info

Publication number: CA3022574A1
Application number: CA3022574A
Authority: CA
Inventors: Rohail Amir
Original assignee: Caterpillar Underground Mining Pty Ltd
Current assignee: Caterpillar Underground Mining Pty Ltd
Priority date: 2018-10-30
Filing date: 2018-10-30
Publication date: 2020-04-30

Abstract

A method for testing operation of a parking brake system of an underground machine is disclosed. The underground machine includes a service brake system working on a brake fluid and a transmission system working on a transmission fluid. The method includes receiving, by a controller, a request for setting a first pressure threshold value for the brake fluid and a second pressure threshold value for the transmission fluid. The method further includes actuating, by the controller, a parking brake of the parking brake system when at least one of: a pressure of the brake fluid is less than the first pressure threshold value or a pressure of the transmission fluid is less than the second pressure threshold value

Description

Description Method for Testing Operation of Parking Brake Systems of Machines Technical Field [0001] The present disclosure relates to testing operation of a parking brake system of a machine. More particularly, the present disclosure relates to a system and method for testing actuation of the parking brake upon a loss of hydraulic pressure in a service brake system and/or a transmission system of the machine.
Background

[0002] Construction machines/equipment generally include hydraulic systems such as a transmission system and a service brake system. The transmission system may include a transmission fluid circulating therein. Similarly, the service brake system may include a brake fluid circulating therein. Such machines incorporate a parking brake system that is automatically applied to stop the machine before a pressure of the brake fluid within the service brake system and/or a pressure of the transmission fluid within the transmission system falls below a threshold pressure.

[0003] Currently, parking brake system use pre-set switches having two states:
'on' and 'off'. When the pressure of the brake fluid and/or the transmission fluid remains more than the threshold pressure, the switches remain in an 'off' state and do not trigger an actuation of the parking brake system. However, when the pressure of the brake fluid and/or the transmission fluid drops to/below the critical pressure, the switches change their state to an 'on' state and trigger the actuation of the parking brake system.

[0004] Depending upon certain factors, such as the introduction of new parts, change in an operational environment or a capacity of the machine, etc., the threshold pressure of each of the brake fluid and the transmission fluid may be changed. To bring about such change, an operator may need to disassemble and/or change one or more components associated with the parking brake system, such as the pre-set switches, with new ones. This is a cumbersome and time-consuming task and leads to downtime of the machine.

[0005] Canadian Patent number 2847791 (hereinafter referred to as CA2847791C) relates to a brake testing apparatus configured to be coupled to a vehicle for testing pressure released spring operated brake systems on the vehicle.
CA2847791C discloses a brake testing apparatus includes a portable control device for activating brake failure test and transmission failure test.
Summary of the Invention

[0006] In an aspect of the present disclosure, a method for testing operation of a parking brake system of an underground machine is disclosed. The underground machine includes a service brake system working on a brake fluid and a transmission system working on a transmission fluid. The method includes receiving, by a controller, a request for setting a first pressure threshold value for the brake fluid and a second pressure threshold value for the transmission fluid. The method further includes actuating, by the controller, a parking brake of the parking brake system when at least one of: a pressure of the brake fluid is less than the first pressure threshold value or a pressure of the transmission fluid is less than the second pressure threshold value.

[0007] In another aspect of the present disclosure, a system for testing operation of a parking brake system of an underground machine is disclosed. The parking brake system includes a parking brake and the underground machine includes a service brake system working on a brake fluid and a transmission system working on a transmission fluid. The system includes an input device and a controller.
The input device is configured to set a first pressure threshold value for the brake fluid and a second pressure threshold value for the transmission fluid. The controller is communicably coupled with the input device and configured to receive the first pressure threshold value and the second pressure threshold value and actuate the parking brake when at least one of a pressure of the brake fluid is less than the first pressure threshold value or a pressure of the transmission fluid is less than the second pressure threshold value.

[0008] In another aspect of the present disclosure, an underground machine is disclosed. The underground machine includes a power producing system, a parking brake system having a parking brake, a service brake system working on a brake fluid, a transmission system working on a transmission fluid, a first sensor configured to detect a pressure of the brake fluid and a second sensor configured to detect a pressure of the transmission fluid. The system also includes a controller communicably coupled with the first sensor and the second sensor. The controller is configured to receive a request for setting a first pressure threshold value for the brake fluid and a second pressure threshold value for the transmission fluid and actuate the parking brake when at least one of the pressure of the brake fluid is less than the first pressure threshold value or the pressure of the transmission fluid is less than the second pressure threshold value.
Brief Description of the Drawings

[0009] FIG. 1 illustrates an exemplary machine, in accordance with an embodiment of the present disclosure;

[0010] FIG. 2 is a diagrammatic illustration of one or more systems and components used in the exemplary machine, in accordance with an embodiment of the present disclosure;

[0011] FIG. 3 illustrates a configuration of a service brake system implemented in the exemplary machine, in accordance with an embodiment of the present disclosure;

[0012] FIG. 4 illustrates a configuration of the service brake system after a braking force has been applied on a brake pedal of the service brake system, in accordance with an embodiment of the present disclosure;

[0013]
FIG. 5 illustrates a testing system for testing operation of a parking brake system, in accordance with an embodiment of the present disclosure;

[0014]
FIG. 6 illustrates the testing system actuating the parking brake upon detection of fault in the transmission system and/or the service brake system, in accordance with an embodiment of the present disclosure;

[0015]
FIG. 7 illustrates an input device in the form of a user interactive display, in accordance with an embodiment of the present disclosure; and

[0016]
FIG. 8 depicts a method for testing operation of the parking brake system of the exemplary machine, in accordance with an embodiment of the present disclosure.
Detailed Description

[0017] Reference will now be made in detail to embodiments of the disclosure, examples of which 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 parts.

[0018]
Referring now to FIG. 1, an exemplary underground machine 100 is illustrated. The underground machine 100 may be operating at a worksite 102, which may include, for example, a mine site, a landfill, a quarry, a construction site, or any other type of worksite. In the embodiment illustrated in FIG. 1, the underground machine 100 is an underground mining machine configured to haul mined material from one location of the worksite 102 to another location on the worksite 102.

However, in various other embodiments the underground machine 100 may be any machine configured to perform one of a dozing operation, a grading operation, a leveling operation, a bulk material removal operation, and/or any other type of operation that results in modifications within the worksite 102. In some embodiments, the underground machine 100 may be a machine having various levels of autonomy, such as a fully autonomous machine, a semi-autonomous machine, and/or a remotely operated machine. In various other embodiments, the underground machine 100 may be used to perform operations associated with industries related to mining, construction, farming, and/or the like.

[0019] The underground machine 100 may include a frame 104, ground engaging members 106, an operator cabin 108, a haulage system 110, a power producing system 112, a transmission system 114 working on a transmission fluid, a service brake system 116 working on a brake fluid and a parking brake system 118.

[0020] The plurality of ground engaging members 106 may be configured to support the frame 104 of the underground machine 100. In the embodiment illustrated, the ground engaging members 106 correspond to wheels. However, in other embodiments, the ground engaging members 106 may correspond to any traction members known in the art (such as tracks, endless belts, etc.). The frame 104 includes a front end 122 and a rear end 124. The front end 122 of the frame 104 may be configured to support the operator cabin 108. The operator cabin 108 may include one or more control devices/interfaces that may enable an operator of the underground machine 100 to control various functionalities of the underground machine 100. For example, the operator cabin 108 may include a display device that may display information to the operator. The operator cabin 108 may also include physically actuable entities such as buttons, joystick, switches and other such equipment known in the art.
[00211 The rear end 124 of the frame 104 may be configured to support the haulage system 110. The haulage system 110 includes a dump body 128 pivotably attached to the frame 104. The dump body 128 is moveable between load carrying position generally parallel to the frame 104 for allowing a payload to be carried and is further moveable in an unillustrated dumping position with the dump body extended upwards and away from the frame 104 for allowing the payload to be dumped. Suitable conventional mechanical or hydraulic lifting mechanisms such as a hydraulic cylinder 130 are provided to allow the dump body 128 to be retracted and extended in the manner well known to those skilled in the art.

[0022] The frame 104 may also be configured to support the power producing system 112. The power producing system 112 includes a power source 126 in the form of an engine and/or an electric power generating system configured to produce torque/power to operate various systems of the underground machine 100. In an embodiment, the power source 126 may be a diesel engine. In another embodiment, the power source 126 may be an electric motor. In various other embodiments, the power source 126 may be any engine running on solid, liquid or gaseous fuel.
[0023] Referring to FIG. 2, the transmission system 114 is illustrated. The transmission system 114 may be coupled to the power producing system 112. The transmission system 114 may include a torque converter for propelling the underground machine 100 on a work surface of the worksite 102. The torque converter may include a pump impeller 132, a turbine impeller 134 opposed to the pump impeller 132, and a stator impeller 136 disposed between the inner peripheries of the pump impeller 132 and the turbine impeller 134. The transmission system may also include a transmission pump 138 within the pump impeller 134. The transmission pump 138 may be a centrifugal pump configured to spin and energize/pressurize the transmission fluid to flow in a radially outward direction.
Such energized transmission fluid may exit the pump impeller 132 and engage with the turbine impeller 134. A plurality of blades on the turbine impeller 134 may be designed to change a direction of flow of the transmission fluid i.e. from an outward radial flow to an inward radial flow. While facilitating the change in direction of the transmission fluid, the turbine impeller 134 absorbs energy of the transmission fluid and starts rotating. Such a rotation translates to a rotation of a propeller shaft 135 that facilitates movement of the ground engaging members 106 on the work surface of the worksite 102.
[0024] Referring to FIG. 3, the service brake system 116 is illustrated. The service brake system 116 may include a brake pedal 140, a master cylinder 142, a reservoir 144, a motor 146, a pump 148, an inlet valve 150, an outlet valve 152 and =
k an accumulator 156 for actuating wheel cylinders 158 of disc brakes on respective ground engaging members 106. The service brake system 116 further includes a first brake line 160, a second brake line 162, a third brake line 164, a fourth brake line 166, a fifth brake line 168, and a sixth brake line 170.
[0025] The brake pedal 140 may be provided in the operator cabin 108 and may be coupled with the master cylinder 142. The brake pedal 140 is configured to be depressed by the operator to generate a brake manipulation force and the master cylinder 142 receives the brake manipulation force from brake pedal 140. The master cylinder 142 is coupled with a reservoir 144 for storing/circulating the brake fluid within the service brake system 116. The master cylinder 142 may be a hydraulic cylinder having a piston and rod arrangement. In another embodiment, the master cylinder 142 may include other type of configurations known in the art.
[0026] The first brake line 160 fluidly couples the pump 148 with the master cylinder 142. The pump 148 may be an energizing device, more particularly a device for pressurizing the brake fluid received from the reservoir 144 and for charging the accumulator 156 with pressurized brake fluid. The pump 148 may be rotary lobe pump, progressing cavity pump, rotary gear pump, piston pump, diaphragm pump, screw pump or other types of pump known in the art configured to receive power from the power producing system 112 via the motor 146.
[0027] The second brake line 162 fluidly couples the master cylinder 142 with the inlet valve 150. The inlet valve 150 may be a two-way valve configured to selectively allow flow of pressurized brake fluid received from the accumulator 156 and/or master cylinder 142 to the wheel cylinders 158.
[0028] The third brake line 164 fluidly couples the inlet valve 150 with the wheel cylinders 158. The wheel cylinders 158 may be hydraulic cylinder having a piston, rod and biasing member arrangement. Such wheel cylinders 158 may be configured to receive pressurized brake fluid and push the piston into the cylinder, biasing the biasing member in the process. The pushing of the piston may cause the wheel =
k cylinder 158 to transmit the necessary force to the disc brake arrangement on the ground engaging member 106 for causing stopping/deceleration of the underground machine 100.
[0029] The fourth brake line 166 fluidly couples the wheel cylinders 158 with the outlet valve 152. The outlet valve 152 may be a two-way valve configured to selectively allow flow of pressurized brake fluid received from the wheel cylinders 158 to the accumulator 156 and/or the master cylinder 142.
[0030] The fifth brake line 168 fluidly couples the outlet valve 152 with the accumulator 156. The accumulator 156 may be a device configured to store pressurized brake fluid and facilitate appropriate braking action by the service brake system 116. The accumulator 156 may be a bladder accumulator, diaphragm accumulator, or piston accumulator. The sixth brake line 170 fluidly couples the accumulator 156 with the pump 148.
[0031] The service brake system 116 also includes a brake controller 172 communicably coupled with the brake pedal 140, the master cylinder 142, the reservoir 144, the motor 146, the pump 148, the inlet valve 150, the outlet valve 152, the accumulator 156 and wheel cylinders 158. The brake controller 172 is configured to facilitate breaking of the underground machine 100 when the operator presses the brake pedal 140. More particularly, when the operator presses the brake pedal 140, the brake controller 172 actuates the pump 148 to pressurize the brake fluid and charge the accumulator 156. Additionally, the brake controller 172 actuates a first mode of operation of the inlet valve 150 and actuates a first mode of operation of the outlet valve 152, as shown in FIG. 3.
[0032] In the first mode of operation, the inlet valve 150 allows flow of pressurized brake fluid (the pressure and amount of brake fluid being directly proportional to the force applied on the brake pedal 140) to the wheel cylinders 158 to facilitate a braking of the underground machine 100. Additionally, the first mode of operation of the outlet valve 152 prevents flow of pressurized brake fluid received =

from the inlet valve 150 to the accumulator 156. Thereby, ensuring that the pressurized brake fluid flows only into the wheel cylinders 158.
[0033]
After the application of braking force, the brake controller 172 is configured to actuate a second mode of operation of the inlet valve 150 and a second mode of operation of the outlet valve 152, as shown in FIG. 4 . In such a configuration, the inlet valve 150 prevents any flow of pressurized brake fluid to the wheel cylinders 158 and the outlet valve 152 allows the pressurized fluid from the wheel cylinder 158 to the accumulator 156 and thereafter back to the master cylinder 142 to restore the service brake system 116 to the original configuration (i.e. a configuration where no brake force is applicable on the brake pedal 140).
[0034] In an aspect of the present disclosure, the service brake system 116 may also include a pressure relief valve 174 disposed on the accumulator 156. The pressure relief valve 174 may be a device configured to control the pressure of the brake fluid in the accumulator 156 of the service brake system 116. More particularly, the pressure relief valve 174 may include a configuration such that pressure in the accumulator 156 is relieved by allowing the pressurized brake fluid to flow from an auxiliary passage out of the accumulator 156.
[0035] In the exemplary scenario illustrated in FIG. 3, the underground machine 100 has the parking brake system 118, which includes a parking brake 180 in the form of a drum brake within the ground engaging member 106. The parking brake 180 may include two drums 182, a biasing member 184 and two actuators 186 for engaging the drums 182 with the ground engaging member 106 to prevent any movement of the underground machine 100.
[0036] While the service brake system 116 and the parking brake system 118 are described herein as disc brakes and drum brakes, respectively, in various other embodiments, other type of brakes/systems may be implemented in such systems.
Additionally, for the purpose of better understanding of the ongoing disclosure, the service brake system 116 has been described with minimum components. However, it may be contemplated by a person skilled in the art that the service brake system 116 may include additional components for servo systems, brake assistance systems, and other similar brake sub-systems known in the art.
[0037] In the present disclosure and illustrations presented, the structure, configuration, etc., of the transmission system 114 and the service brake system 116 are exemplary in nature. It may be contemplated by a person of ordinary skill in the art that said systems (the transmission system 114 and the service brake system 116) may work on other configurations and principles (with the use of hydraulic fluid therein). Accordingly, it will be understood by those or ordinary skill in the art that various additional embodiments may be contemplated by the modification of the disclosed systems without departing from the spirit and scope of what is disclosed.
[0038] Referring now to FIG. 3, the testing system 120 is illustrated, in accordance with an embodiment of the present disclosure. The testing system includes one or more first sensors 202 and one or more second sensors 204, (also shown in FIG. 5).
[0039] The first sensors 202 may be configured to detect the pressure of the brake fluid within the service brake system 116. In the embodiment illustrated in FIG. 3, one first sensor 202 may be positioned on the accumulator 156 and one first sensor 202 may be positioned on the second brake line 162. The first sensors 202 may configured to detect a pressure of the brake fluid in the accumulator 156 and/or any pressure loss within the service brake system 116. Some examples of first sensors 202 may include, but are not limited to, strain gauges pressure transducers, capacitive pressure transducers, piezoelectric pressure sensor, Inductive/Reluctive pressure sensors, optical based pressure sensors, diaphragm-based pressure transducers and the like.
[0040] The second sensors 204 may correspond to pressure sensors installed in the transmission system 114, as shown in FIG. 2. For example, in some embodiments, the second sensors 204 may be installed in the torque converter and at the outlet of the transmission pump 138 of the transmission system 114. The second sensors may configured to detect a pressure of the transmission fluid supplied to the torque converter and present within the torque converter. The second sensors 204 may correspond to strain gauges pressure transducers, capacitive pressure transducers, piezoelectric pressure sensor, Inductive/Reluctive pressure sensors, optical based pressure sensors and diaphragm-based pressure transducers.
[0041] Referring to FIG. 3 and FIG. 7, the testing system 120 further includes an input device 206 configured to be used to set a first pressure threshold value for the brake fluid and a second pressure threshold value for the transmission fluid.
More specifically, the input device 206 may be used by the operator for setting one or more testing parameters such as the pressure threshold values for the transmission fluid and the brake fluid. The pressure threshold values may be defined as a magnitude of pressure within a system (such as the transmission system 114 and the service brake system 116) below which the system may not operate properly. In the embodiment illustrated, the input device 206 may be a display unit 207 (interactive input device) configured to display a user interface to the operator of the underground machine 100. In some embodiments, the display unit 207 may be a Light Emitting Diode (LED) display, an Edge LED display, a Thin Film Transistor (TFT) display, a Liquid Crystal Display (LCD) display, and/or the like. In some embodiments, the display unit 207 may receive input from the operator. In such an implementation, the display unit 207 includes touch sensitive layer (either capacitive or resistive layer) to receive input from the operator. In the embodiment illustrated, the display unit 207 also includes a plurality of buttons 209 for initiating the exemplary test of the present disclosure (will be described below).
[0042] The testing system 120 may further include a controller 208 having a memory 210 and a transceiver 212. The controller 208 may be communicatively coupled to each of the first sensors 202, second sensors 204, the brake controller 172, the transmission system 114, the parking brake system 118 and the input device 206, to control and monitor their respective operations. The controller 208 may include suitable logic, circuitry, and/or interfaces that are operable to execute one or more instructions stored in the memory 210 to perform a predetermined operation.
More particularly, according to an aspect of the present disclosure, the controller 208 is configured to perform testing of the parking brake system 118, brake system 116 and the transmission system 114 (as will be described later in the specification).
100431 In an embodiment, the controller 208 may be an electronic control module ("ECM"), which may include, for example, an on-board computer with one or more processors (such as, but not limited to, an X86 processor, a Reduced Instruction Set Computing (RISC) processor, an Application Specific Integrated Circuit (ASIC) processor, a Complex Instruction Set Computing (CISC) processor, an Advanced RISC Machine (ARM) processor or any other processor) for performing calculations, executing functions, and accessing machine information stored in a memory location (memory 210). Examples of machine information may include, for example, a 3-D
terrain map showing a profile of the worksite 102 produced using surveying techniques, and data provided by atleast one sensor (202, 204) included in underground machine 100.
100441 In another embodiment, the controller 208 may be an ECU (electronic control unit) configured to control the operation of the underground machine 100 at the worksite 102 and perform testing of the parking brake system 118, brake system 116 and the transmission system 114. The electronic control unit (ECU) may be a digital computer that may include a central processing unit (CPU) for executing a set of instructions on a data set. For example, the ECU i.e. controller 208 may receive input signals from various sensors (202, 204 and other sensors not shown) that represent various engine/power source 126 operating conditions. More particularly, an accelerator opening signal from an accelerator opening sensor may detect engine load and a crank angle signal from a crank angle sensor may detect the angular position of a crankshaft (not shown). Such sensed information may be used by the controller 208 (ECU) to control various parameters that govern operation of the engine/power source 126 and also control the power to be transmitted to various systems of the underground machine 100, by the engine/power source 126.
[0045] In an embodiment, the controller 208 may be a control module in addition to the ECU/ECM of the underground machine 100. The controller 208 may be operating in an independent manner. The controller 208 in such a configuration may be bi-directionally communicating with the ECU/ECM to test the operation of the parking brake system 118, brake system 116 and the transmission system 114 and control operation of various systems of the underground machine 100.
[0046] The memory 210 of the controller 208 stores a set of instructions and data that are executable by the controller 208 to perform predetermined operations such as controlling the service brake system 116 and actuating the parking brake system 118 when a pressure loss is detected in the service brake system 116 and/or transmission system 114. Some of the memory 210 implementations include, but are not limited to, a random-access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), and a secure digital (SD) card.
[0047] The transceiver 212 may correspond to suitable logic, circuitry, and/or interfaces may be configured to transmit and receive data from one or more other components of the underground machine 100 (such as the first sensors 202 and the second sensor 204) and/or other machines and remote server (such as the controller 208). The transceiver 212 may utilize one or more communication protocols to transmit and receive data from the components and one or more computing devices.
Examples of such communication protocols may include, but are not limited to, Transport Control Protocol/Internet Protocol (TCP/IP), 3G, 4G, 2G, Bluetooth, Zigbee, Inter-IC (I2C), and/or the like.

Industrial Applicability [0048] The operation of the testing system 120 and the functioning of the controller 208 will now be explained in conjunction with FIG. 2 ¨ FIG. 7 and few exemplary scenarios. Let us assume that the operator activates a parking brake test module to test the parking brake 180. This may be achieved by pressing a button, activation through touch screen, etc. In an embodiment, the operator may press a combination of buttons 209 to initiate 'TEST 1' for checking functionality of the parking brake system 118 of the underground machine 100. The 'TEST l' may be configured to check actuation of the parking brake 180 owing to a pressure drop in the transmission fluid in the transmission system 114 below the second pressure threshold value. The input device 206, more specifically, the display unit 207, may prompt the operator, for example, through a pop-up window to set or feed a first pressure threshold value for the brake fluid and a second pressure threshold value for the transmission fluid. In an embodiment, the display unit 207 may present an on screen (touch) keyboard for the operator to set the first pressure threshold value for the brake fluid and the second pressure threshold value for the transmission fluid.
The first pressure threshold value for the brake fluid and the second pressure threshold value for the transmission fluid are communicated to the controller 208.
[0049] After the operator sets/inputs the value of the first pressure threshold value for the brake fluid and the second pressure threshold value for the transmission fluid, the controller 208 decouples the power producing system 112 with the transmission system 114, thereby stopping supply of torque/energy to the transmission pump 138.
This causes the pressure within the transmission system to drop. The second sensors 204 continuously monitor the pressure of the transmission fluid within the transmission system 114 and transmit this information, via the transceiver 212, to the controller 208. Referring to FIG. 6, the controller 208 may create a pressure graph on the display unit 207 to dynamically indicate live values of the pressure decrease of the transmission fluid. When the pressure of the transmission fluid reaches a magnitude that is less than or equal to the second pressure threshold value, the controller 208 displays a transmission failure indicator (e.g., in the form of an icon 220) on the display unit 207. Simultaneously, the controller 208 actuates the actuator 186 for applying the parking brake 180. Concurrently, the controller displays a notification/indication on the display unit 207 i.e. parking brake indicator in the form of an icon 222. In an embodiment, the controller 208 may also produce an audio signal to provide an indication that the parking brake 180 has been actuated.
[0050] In some implementations, the testing system 120 may include a third sensor 230 coupled to the parking brake system 118 to detect an actuation of the parking brake 180. If the controller 208 is unable to actuate the actuator 186 pursuant to a drop in pressure of the transmission fluid below the second threshold, a corresponding information may be communicated by the third sensor 230 to the controller 208. In some implementations, the controller 208 may be configured to generate a notification (via an alarm or a message or an icon 226 on the display unit 207, etc.) if the parking brake 180 has not been properly actuated.
[0051] The testing system 120 may also be configured to check actuation of the parking brake 180 owing to a pressure drop in the brake fluid in the service brake system 116 below the first threshold. Firstly, the controller 208 may deactivate the parking brake 180 (that was activated as part of TEST 1). The controller 208 may also adjust the display on the display unit 207 for a second test (i.e. a test to check actuation of the parking brake 180 on pressure drop of the brake fluid in the service brake system 116) by displaying a message (such as "TEST 2") on the display unit 207. As part of TEST 2, the controller 208 decouples the pump 148 of the service brake system 116 with the power producing system 112, preventing any power/energy transfer to the pump 148.
[0052] The controller 208 may be communicably coupled with the pressure relief valve 174 disposed on the accumulator 156 and may be configured to control the pressure relief valve 174 to release the pressure of the brake fluid within the =

accumulator 156 in a controlled manner. In an embodiment, the pressure relief valve 174 may be communicably coupled with the controller 208 and the controller 208 may have suitable logic and/or may be coupled to suitable circuitry to control the pressure relief valve 174 to release the pressure of the brake fluid within the accumulator 156 in a controlled manner. In an embodiment, the pressure relief valve 174 may be controlled by the operator/serviceman to release the pressure of the brake fluid within the accumulator 156 in a controlled manner.
[0053] Controlling the pressure relief valve 174 in the manner as described above, causes the pressure within the service brake system 116 to drop. This pressure drop within the service brake system 116 is because the two sources capable of pressurizing the brake fluid i.e. the pump 148 and the accumulator 156 have been rendered ineffective (due to decoupling of the power producing system 112 with the pump 148 and release of the pressure built up within the accumulator 156).
[0054] The first sensor 202 provided on the accumulator 156 and the first sensor 202 provided on the second brake line 162, continuously monitor the pressure of the brake fluid within the service brake system 116 and transmit this information, via the transceiver 212, to the controller 208. The controller 208 may create a pressure graph on the display unit 207 to dynamically indicate live values of the pressure decrease of the brake fluid within the service brake system 116. When the pressure of the brake fluid reaches a magnitude that is less than or equal to the first pressure threshold value, the controller 208 displays a brake failure indicator (e.g., in the form of an icon 228) on the display unit 207. Simultaneously, the controller 208 actuates the actuator 186 for applying the parking brake 180. Concurrently, the controller 208 displays a parking brake indicator (in the form of the icon 222) on the display unit 207.
[0055] The testing system 120 as disclosed facilitates as a test to check proper functionality of the parking brake 180. More particularly, the controller 208 mimics conditions corresponding to failure of the transmission system 114 and the service =

brake system 116 to check whether on detection of failure in the said systems the parking brake 180 is automatically actuated. Automatic actuation of the parking brake 180 when at least one of the pressure of the brake fluid is less than the first pressure threshold value or the pressure of the transmission fluid is less than the second pressure threshold value suggests to the operator that the parking brake 180 is working as desired. Alternatively, non-actuation of the parking brake 180 when at least one of the pressure of the brake fluid is less than the first pressure threshold value or the pressure of the transmission fluid is less than the second pressure threshold value suggests to the operator that the underground machine 100 is in need of servicing.
[0056] In another aspect of the present disclosure, a method 800 for testing operation of the parking brake system 118 of the underground machine 100 is disclosed, as shown in FIG. 8. The method 800 includes receiving, by the controller 208, a request for setting the first pressure threshold value for the brake fluid circulating in the service brake system 116 and the second pressure threshold value for the transmission fluid circulating in the transmission system 114 (step 802). The request for setting the first pressure threshold value for the brake fluid and the second pressure threshold value for the transmission fluid is generated by the controller 208 by displaying a message on the input device 206 i.e. the display unit 207 prompting the operator to enter the threshold pressure values for the brake fluid and the transmission fluid, respectively.
[0057] The controller 208 initiates 'TEST 1' by decoupling the power producing system 112 with the transmission system 114, thereby stopping supply of torque/energy to the transmission pump 138. This causes the pressure within the transmission system 114 to drop. The second sensors 204 continuously monitor the pressure of the transmission fluid within the transmission system 114 and transmit this information, via the transceiver 212, to the controller 208. In case, the pressure of the transmission fluid is less than the second pressure threshold value, the controller 208 actuates, the parking brake 180 of the parking brake system 118 (step 804).
[0058] In a similar manner, the controller 208 may concurrently run a parallel test i.e. 'TEST 2' for checking the actuation of the parking brake 180 on detection of a fault in the service brake system 116. The controller 208, communicably coupled with the pressure relief valve 174, may be configured to control the pressure relief valve 174 to release the pressure of the brake fluid within the accumulator 156 in a controlled manner. This causes the pressure within the service brake system 116 to drop. The first sensors 202 continuously monitor the pressure of the brake fluid within the service brake system 116 and transmit this information, via the transceiver 212, to the controller 208. In case, the pressure of the brake fluid is less than the first pressure threshold value, the controller 208 actuates the parking brake 180 of the parking brake system 118 (step 804).
[0059] The testing system 120 and the method 800 as disclosed in the present disclosure, provide an operator with the capability to test the automatic actuation of the parking brake 180, thereby obviating the need for the operator to take the underground machine 100 to the service station (as is done currently in the art).
Additionally, the testing system 120 provided on board the underground machine 100 provides an advantage over existing testing jigs by eliminating the need to connect/couple a testing apparatus for checking the correct functionality of the parking brake system 118. Moreover, the testing system 120 and the method 800, as disclosed herein provide the operator with means for setting parameters used in testing functionality of the parking brake 180. Thereby, obviating the need for the operator to disassemble and/or change one or more components associated with the parking brake system, such as the pre-set switches, with new ones for implementing a change in threshold parameters (as is done currently in the art). This prevents downtime of the underground machine 100 and eliminates the additional cost for installing new components.

=

[0060]
While aspects of the present disclosure have seen particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

LIST OF ELEMENTS
TITLE: Method for Testing Operation of Parking Brake Systems of Machines 100 Underground machine 102 Worksite 104 Frame 106 Ground engaging members 108 Operator cabin 110 Haulage system 112 Power producing system 114 Transmission system 116 Service brake system 118 Parking brake system 120 Testing system 122 Front end of frame 104 124 Rear end of frame 104 126 Power source 128 Dump body 130 Hydraulic cylinder 132 Pump impeller 134 Turbine impeller 135 Propeller Shaft 136 Stator Impeller 138 Transmission pump 140 Brake pedal 142 Master cylinder 144 Reservoir 146 Motor ' =
, , -21-148 Pump 150 Inlet valve 152 Outlet valve 156 Accumulator 158 Wheel cylinder 160 First fluid line 162 Second fluid line 164 Third fluid line 166 Fourth fluid line 168 Fifth fluid line 170 Sixth fluid line 172 Brake controller 174 Pressure relief valve 180 Parking brake 182 Drum 184 Biasing member 186 Actuator 202 First sensor 204 Second sensor 206 Input device 207 Display unit 208 Controller 209 Plurality of buttons 210 Memory 212 Transceiver 220 Transmission failure indicator icon on display unit 222 Parking brake indicator icon on display unit 207 226 Non-Actuation of Parking brake icon on display unit 228 Brake failure indicator icon on display unit 207 230 Third sensor 800 Method 802 Step 804 Step

Claims

Claims What is claimed is:

1. A method for testing operation of a parking brake system of an underground machine, the underground machine including a service brake system working on a brake fluid and a transmission system working on a transmission fluid, the method comprising:
receiving, by a controller, a request for setting a first pressure threshold value for the brake fluid and a second pressure threshold value for the transmission fluid;
actuating, by the controller, a parking brake of the parking brake system when at least one of:
a pressure of the brake fluid is less than the first pressure threshold value; or a pressure of the transmission fluid is less than the second pressure threshold value.

2. The method of claim 1 further comprising detecting, by a first sensor, the pressure of the brake fluid.

3. The method of claim 2 further comprising detecting, by a second sensor, the pressure of the transmission fluid.

4. The method of claim 3, further comprising stopping, by the controller, a power transfer to the service brake system and the transmission system prior to detection of the pressure of the brake fluid and the pressure of the transmission fluid.

5. The method of claim 1 wherein the controller receives the first pressure threshold value and the second pressure threshold value from an interactive input device.

6. The method of claim 1, further comprising:
generating, by the controller, a notification if the parking brake is actuated.

7. The method of claim 1, further comprising:
displaying, by the controller, a transmission failure indicator, on a display when the pressure of the transmission fluid is less than the second pressure threshold value.

8. The method of claim 1, further comprising:
displaying, by the controller, a brake failure indicator, on a display when the pressure of the brake fluid is less than the first pressure threshold value.

9. The method of claim 1, further comprising controlling a relief valve coupled to the service brake system to release the pressure of the brake fluid circulating within the service brake system.

10. A system for testing operation of a parking brake system of an underground machine, the parking brake system including a parking brake and the underground machine including a service brake system working on a brake fluid and a transmission system working on a transmission fluid, the system comprising:

an input device configured to set a first pressure threshold value for the brake fluid and a second pressure threshold value for the transmission fluid; and a controller communicably coupled with the input device, the controller configured to:
receive the first pressure threshold value and the second pressure threshold value; and actuate the parking brake when at least one of:
a pressure of the brake fluid is less than the first pressure threshold value; or a pressure of the transmission fluid is less than the second pressure threshold value.

11. The system as claimed in claim 10 further comprising a first sensor configured to detect a pressure of the brake fluid and a second sensor configured to detect a pressure of the transmission fluid.

12. The system as claimed in claim 10 wherein the controller is configured to stop power transfer to the service brake system and the transmission system.

13. The system as claimed in claim 10 wherein the controller is further configured to provide an indication if the parking brake has been actuated.

14. The system as claimed in claim 10 wherein the controller is further configured to:
display a transmission failure indicator on an interactive display when the pressure of the transmission fluid is less than the second pressure threshold value; and display a brake failure indicator on the interactive display when the pressure of the brake fluid is less than the first pressure threshold value.

15. The system as claimed in claim 10, wherein the controller is further configured to control a relief valve coupled to the service brake system to release the pressure of the brake fluid within the service brake system.

16. An underground machine including:
a power producing system;
a parking brake system having a parking brake;
a service brake system working on a brake fluid;
a transmission system working on a transmission fluid;
a first sensor configured to detect a pressure of the brake fluid and a second sensor configured to detect a pressure of the transmission fluid; and a controller communicably coupled with the first sensor and the second sensor, the controller configured to:
receive a request for setting a first pressure threshold value for the brake fluid and a second pressure threshold value for the transmission fluid;
actuate the parking brake when at least one of:
the pressure of the brake fluid is less than the first pressure threshold value; or the pressure of the transmission fluid is less than the second pressure threshold value.

17. The underground machine as claimed in claim 16 further comprising an input device configured to set the first pressure threshold value and the second pressure threshold value.

18. The underground machine as claimed in claim 16 wherein the controller is configured to stop a power transfer from the power producing system to the service brake system and the transmission system.

19. The system as claimed in claim 10 wherein the controller is further configured to generate a notification if the parking brake has been actuated.

20. The underground machine as claimed in claim 16 wherein the service brake system includes a pressure relief valve; and the controller is configured to control the pressure relief valve to release the pressure of the brake fluid within the service brake system.