SYSTEMS AND METHODS FOR DIAGNOSING A CONTINUOUSLY VARIABLE TRANSMISSION

Abstract

A vehicle diagnostic system is provided for diagnosing a drive belt in a continuously variable transmission. A diagnostic circuit detects or predicts a drive belt failure based on an operating parameter received from a sensor associated with the vehicle during a predetermined diagnostic period.

Description

SYSTEMS AND METHODS FOR DIAGNOSING A VARIABLE TRANSMISSION CONTINUOUSLY / nOP ίΠ / 77Π7 / Β / ΥΙΛΙ Field of Invention This description relates generally to vehicle diagnostic systems, and more specifically to diagnostic systems for a drive belt used in a continuously variable transmission (CVT). Background of the Invention Conventional vehicles, including SUVs and side-by-sides, have an internal combustion engine that generates driving torque. To drive the engine's pistons, an air / fuel mixture is ignited inside the cylinders and regulated by intake and exhaust valves. The intake valves open selectively to draw air into the cylinders, where it mixes with the fuel to form an air / fuel mixture. To allow exhaust gas to escape the cylinders after combustion, the exhaust valves open selectively at specific times. Continuously variable transmissions (CVTs) are typically installed in recreational vehicles, such as snowmobiles and all-terrain vehicles. - 2 CVTs provide an infinite number of different gears that are effective in transmitting torque from the engine to a transmission output drive line. The output drive line operatively couples the transmission to at least one member in contact with the ground. However, due to the CVT's belt-driven construction, one drawback is that the CVT's drive belt tends to wear out and become damaged prematurely when it is not broken in properly or when it is used excessively under undesirable conditions. Since the drive belt is solely responsible for transmitting engine power from the drive pulley to a driven pulley on the CVT, it is a critical component of the CVT. Typically, the CVT drive belt is a V-belt made of rubber, usually fiber-reinforced, which is rigid across its width but flexible along its length. During operation, the drive belt experiences extreme pressure and friction. When the drive belt loses pressure due to CVT shear under high load or overload conditions, slippage can occur, causing belt damage such as spin burn or an hourglass event. For example, during a spin burn event, the belt temperature can reach / nOP iΠ / 77Π7 / Β / YΙΛΙ The current diagnostic system provides enhanced presentations and relationships of real-time operating parameters. Additionally, operating parameters are automatically displayed without significant manual intervention. As a result, the overall operating time of an engine system is increased without incurring additional operating and maintenance costs. In an exemplary embodiment, a vehicle diagnostic method is provided for a vehicle that includes an internal combustion engine and a continuously variable transmission (CVT) operatively coupled to the internal combustion engine. The method comprises the steps of detecting at least one engine crankshaft acceleration variation event using a detection circuit; determining at least one operating parameter received from one or more sensors associated with CVT operation using a monitoring circuit; and determining, based on at least one operating parameter, when the detected engine crankshaft acceleration variation is related to a CVT drive belt failure using an alert circuit.In one example, the diagnostic method further comprises including an environmental condition parameter as at least one operating parameter, where the environmental condition parameter includes at least one of / ñor ίΠ / 77Π7 / Β / YΙΛΙ. - 5 a fuel status signal, an engine coolant temperature signal, a drive belt temperature signal, and a clutch status signal. In another example, the diagnostic method further comprises including an engine-based parameter as at least one operating parameter, wherein the engine-based parameter is related to at least one of a crankshaft acceleration signal, an engine torque signal, and a transmission gear position signal. In a further example, the diagnostic method further comprises including a driveline-based parameter as at least one operating parameter, wherein the driveline-based parameter is related to at least one of a vehicle speed signal, an engine speed signal, and a wheel speed signal.In another example, the diagnostic method further comprises detecting at least one engine crankshaft acceleration variation event by measuring an acceleration or deceleration rate and a crankshaft acceleration signal. In another example, the diagnostic method further comprises detecting at least one engine crankshaft acceleration variation event based on a variation pattern of the operating parameter measured over a predetermined period of time. In one variation thereof, the diagnostic method further comprises determining whether a frequency of the variation pattern is greater than a certain threshold. - 6. Predetermined threshold. In another variation thereof, the diagnostic method further comprises determining whether a pattern variation time period is greater than a predetermined time period. In a refinement of the variation thereof, the diagnostic method further comprises determining whether there is a pattern variation magnitude. In a further example, the diagnostic method further comprises performing a first correction method to determine whether the engine crankshaft acceleration variation event is caused by a belt slippage event or an internal combustion misfire event based on a single occurrence of at least one engine crankshaft acceleration variation event.In an additional example, the diagnostic method further comprises performing a second correction method to determine whether the engine crankshaft acceleration variation event is caused by a belt slippage event or an engine combustion misfire event based on a plurality of presentations of at least one engine crankshaft acceleration variation event. In another exemplary embodiment, a vehicle diagnostic method is provided for a vehicle that includes an internal combustion engine and a continuously variable transmission (CVT) operatively coupled to the terminal. The method comprises determining at least one parameter of / ñor ίΠ / 77Π7 / Β / YΙΛΙ - 7. Operation received from one or more sensors associated with a CVT operation using a monitoring circuit; detect at least one belt slippage event of a CVT drive belt using a detection circuit; determine, based on at least one operating parameter, when at least one detected belt slippage event relates to a CVT drive belt impedance failure using an alert circuit; and notify of the drive belt impedance failure before damage occurs to the belt or the vehicle's driveline, using the alert circuit. In one example, the diagnostic method further comprises generating an information signal related to the drive belt impedance failure.In another example, the diagnostic method further comprises providing an option to override a user input by adjusting at least one value of at least one operating parameter. In a further example, the diagnostic method further comprises detecting at least one belt slippage event by the detection circuit in at least one of a feedback control mode and one active control mode. In another further example, the diagnostic method further comprises receiving a desired vehicle input parameter using the monitoring circuit. In yet another example, the diagnostic method further comprises including / ñor iP / 77P7 / B / YILI. - 8 an environmental condition parameter as at least one operating parameter. In another additional example, the method further comprises including a motor-based parameter as at least one operating parameter. In another additional example, the diagnostic method further comprises including a driveline-based parameter as at least one operating parameter. In yet another example, the diagnostic method further comprises detecting the belt slippage event based on a comparison of a motor-based parameter and a driveline-based parameter to predict the impedance failure of the drive belt. In a variation thereof, the diagnostic method further comprises determining whether at least one of the motor-based parameter and the driveline-based parameter is greater than a predetermined threshold.In an additional example, the diagnostic method further comprises reporting at least one detected belt slippage event using a display; and automatically adjusting at least one operating parameter based on a predetermined table. In a further exemplary embodiment, a vehicle diagnostic method is provided for a vehicle that includes an internal combustion engine and a continuously variable transmission (CVT) operatively coupled to the internal combustion engine. The method comprises the following steps: / nOP ίΠ / 77Π7 / Β / ΥΙΛΙ - 9. Determine at least one operating parameter received from one or more sensors associated with CVT operation using a monitoring circuit; detect at least one critical belt-life event of a CVT drive belt using a detection circuit; determine, based on at least one operating parameter, when at least one detected critical belt-life event corresponds to a CVT drive belt failure using an alert circuit; and generate an information signal related to the drive belt life using the alert circuit. In one example, the diagnostic method further comprises including an environmental condition parameter as the at least one operating parameter, where the environmental condition parameter includes a temperature signal.In a further example, the diagnostic method further comprises including an engine-based parameter as at least one operating parameter, where the engine-based parameter is related to at least one of an engine load signal, a throttle position signal, an engine torque signal, and an engine power signal. In a further example, the diagnostic method further comprises including a driveline-based parameter as at least one operating parameter, where the driveline-based parameter is related to at least one of / ñor ίΠ / 77Π7 / Β / YΙΛΙ. - 10. A vehicle speed signal and an engine speed signal. In a further example, the diagnostic method further comprises detecting the critical belt life event based on a comparison of an engine-based parameter, a driveline-based parameter, and an environmental condition parameter; and predicting the remaining life of the drive belt based on the comparison. In a variation thereof, the diagnostic method further comprises determining whether the remaining life of the drive belt is less than a predetermined threshold. In another variation thereof, the diagnostic method further comprises displaying the information signal on a screen using a textual or graphical indicator associated with the remaining life of the drive belt.In another example, the diagnostic method further comprises adjusting at least one motor-based parameter, one transmission line-based parameter, and one environmental condition parameter based on at least one critical belt life event detected. In a further exemplary embodiment of the present description, a vehicle diagnostic method is provided for a vehicle that includes an internal combustion engine and a continuously variable transmission (CVT) operatively coupled to the internal combustion engine. The method comprises the steps of: determining an amount of input energy supplied by the CVT to the engine. - 11 Internal combustion; determine the amount of thermal energy output from the CVT; determine, based on the amount of energy input and the amount of thermal energy output, the amount of energy stored in the CVT; compare the amount of stored energy to a threshold; and reduce the amount of energy input in response to the amount of stored energy satisfying the threshold. In one example, the step of reducing the amount of energy input includes the step of reducing the power supplied by the internal combustion engine to the CVT. In another example, the amount of energy input is determined based on the mechanical input characteristics of the CVT. In yet another example, the amount of thermal energy output is determined based on the fluid characteristics of the CVT.In another example, the stage of determining the amount of input energy supplied to the CVT by the internal combustion engine includes the steps of: determining a power output of the internal combustion engine; determining a CVT clutch efficiency based on the determined power output; and determining the amount of input energy supplied by the CVT based on the determined power output and the determined CVT clutch efficiency. In a variation thereof, the stage of determining the CVT clutch efficiency based on the determined power output / ñor ίΠ / 77Π7 / Β / YΙΛΙ. Step 12 includes the step of retrieving the determined CVT clutch efficiency from a database. In another example, the step of determining the amount of thermal energy output leaving the CVT includes the steps of: determining an air temperature of the air entering the CVT; and determining the amount of thermal energy output leaving the CVT based on the CVT clutch airflow model, a heat transfer coefficient, and the determined air temperature. In a further exemplary embodiment of the present description, a vehicle diagnostic method is described for a vehicle that includes an internal combustion engine and a continuously variable transmission (CVT) operatively coupled to the internal combustion engine. The method comprises the steps of: detecting a plurality of engine crankshaft acceleration variation events; determining a frequency of the plurality of engine crankshaft acceleration variation events; determining a CVT belt interaction frequency of a CVT drive belt; and classifying the plurality of engine crankshaft acceleration variation events as either an engine misfire event or a CVT belt damage event based on a comparison of the CVT belt interaction frequency. In an example thereof, the step of determining the interaction frequency of / nOP iP / 77P7 / B / YILI - 13 CVT belts of the CVT drive belt includes the steps of: determining a pitch diameter of a CVT drive clutch; determining a linear speed of the CVT drive belt based on the determined pitch diameter of the drive clutch and a rotational speed of a CVT drive shaft; and determining the CVT belt interaction frequency of the drive belt based on the determined linear speed of the CVT drive belt and the belt length. The additional features and advantages of the present description will become evident to those skilled in the field upon consideration of the following detailed description of the illustrative embodiment that exemplifies the best way to carry out the invention as currently perceived. Brief Description of the Figures The modalities will be more easily understood in view of the following description when accompanied by the following figures, where similar reference numbers represent similar elements, where: Figure 1 illustrates a representative side-by-side view of a drivetrain of an exemplary vehicle; Figure 2 illustrates a representative view of an initial airflow for an exemplary continuously variable transmission (CVT); Figure 3 illustrates an exemplary block diagram / nOP ίΠ / 77Π7 / Β / ΥΙΛΙ - 14 and a schematic view of an illustrative modality of a diagnostic system having an engine control circuit and a diagnostic circuit; Figure 4 illustrates an exemplary processing sequence of the present diagnostic system to detect a belt slippage event in a retroactive control mode; Figure 5 illustrates an exemplary processing sequence of the current diagnostic system execution to detect the belt slippage event in a proactive control mode; Figure 6 illustrates an exemplary processing sequence of the present diagnostic system to detect a critical band life event; Figure 7 illustrates an exemplary processing sequence of the present diagnostic system to detect an engine misfire event; Figure 8 illustrates an exemplary processing sequence of the present diagnostic system to detect an engine misfire event or a damaged belt event; Figure 9 illustrates an exemplary processing sequence for determining a CVT band interaction frequency; Figure 10 illustrates a processing sequence / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 15 examples of peak output power regulation of a power source based on the energy stored in a CVT; Figure 11 illustrates an exemplary processing sequence for determining an amount of energy input into a CVT during CVT operation; and Figure 12 illustrates an exemplary processing sequence for determining an amount of energy output from a CVT during CVT operation. The corresponding reference numbers indicate parts shown in the various views. Although the figures represent variations of the description, they are not necessarily to scale, and certain features may be exaggerated to better illustrate and explain the description. The examples provided herein illustrate one exemplary variation of the description, and these examples should not be considered as limiting the scope of the description in any way. Detailed Description of the Invention The embodiments described below are not intended to be exhaustive or to limit the invention to the precise forms described in the following detailed description. Rather, the embodiments are selected and described in such a way that other persons skilled in the field may benefit from their teachings. Although the present / ñor ίΠ / 77Π7 / Β / ΥΙΛΙ - The description in section 16 relates primarily to a continuously variable transmission (CVT). It should be understood that the features described herein may be incorporated into one or more vehicles. Exemplary vehicles include all-terrain vehicles, side-by-side UTVs, utility vehicles, motorcycles, snowmobiles, golf carts, and other vehicles or devices incorporating a continuously variable transmission. With reference to Figure 1, a representative view of a vehicle 100 is shown. The vehicle 100, as illustrated, includes a plurality of ground-contacting members 102. For illustrative purposes, the ground-contacting members 102 are wheels 104 with associated tires. Other exemplary ground-contacting members include skids and tracks. In one embodiment, one or more of the wheels may be replaced with tracks, as, for example, on the Prospector II Tracks available from Polaris Industries, Inc., located at 2100 Highway 55 in Medina, Minn. 55340. One or more of the members 102 in contact with the ground are operatively coupled to a gearbox 130 to energize the movement of the vehicle 100. Other types of transmission, such as non-gearboxes, are also contemplated. Exemplary power sources 106 include internal combustion engines and / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 17 electric motors. In the illustrated configuration, power source 106 is an internal combustion engine. An internal combustion power source 106 is represented in Figure 1. The power source 106 receives fuel from a fuel source 108 and ambient air from an air intake system 110. For example, ambient air is selectively supplied to the power source 106 to be mixed with the fuel for internal combustion. Exhaust gas is expelled from the power source 106 through an outlet system 112. An output shaft 120 from the power source 106 is coupled to a drive member of a continuously variable transmission (CVT unit) 122. A driven member of the CVT unit 122 is operatively coupled to the drive member of the CVT unit 122 via a drive belt. The CVT unit 122 receives ambient air through an air intake system 124 and expels air from inside the CVT unit 122 through an exhaust system 126.The driven member is coupled to an output shaft 128 which is operatively coupled to an input of a gear transmission 130. A first output shaft 132 of a gearbox 130 is coupled to a rear-driven unit 134. The rear-driven unit 134 is coupled to corresponding wheels 104 of a rear axle 136 via / ñor ίΠ / 77Π7 / Β / YΙΛΙ - 18 half-shafts 138. The rear drive unit 134 may be a differential. A second transmission output shaft 140 is coupled to a front drive unit 142. The front drive unit 142 is coupled to corresponding wheels 104 of the front axle 144 via half-shafts 138. The front drive unit 142 may be a differential. Various configurations of the rear drive unit 130 and the front drive unit 142 are considered. Regarding the rear drive unit 134, in one configuration, it is a locked differential where power is delivered to both wheels on axle 136 via output shafts 150. In another configuration, the rear drive unit 134 is a lockable / releaseable differential relative to output shafts 150. In a locked configuration, power is delivered to both wheels on axle 136 via output shafts 150. When the rear drive unit 134 is in a released configuration, power is delivered to one wheel on axle 136, specifically the wheel with the least resistance relative to the ground, via output shafts 150.Regarding the front-mounted drive unit 142, in one mode the front-mounted drive unit 142 has a first configuration where power is supplied to / nOP ίΠ / 77Π7 / Β / YΙΛΙ. - 19 both of the front axle 144 wheels and a second configuration where the power is provided to one of the axle 144 wheels, such as the wheel that has the least resistance relative to the ground. In one configuration, the front drive unit 142 includes active downshift control (ADC). The ADC is a drive system that provides torque transfer as needed to the front wheels when one of the rear axle wheels 104 loses traction and provides engine braking torque to the front axle wheels 104. Both the on-demand torque transfer and engine braking features of the front drive unit 142 can be active or inactive. In the case of on-demand torque transfer, when active, power is provided to both front axle wheels 144, and when inactive, power is provided to one of the front axle wheels 144. In the case of engine braking, when active, engine braking is provided to the front axle wheels 144, and when inactive, no engine braking is provided to the front axle wheels 144.Other suitable layouts for a two-wheel drive system are contemplated to suit the application. Exemplary front-wheel drive units are described in U.S. Patent Application No. / nOP ίΠ / 77Π7 / Β / YΙΛΙ. - 20 series 12 / 816,052, filed on June 15, 2010, and entitled ELECTRIC VEHICLE, United States Patent No. 5,036,939 and United States Patent RE38,012E, descriptions of which are expressly incorporated herein by reference. In one embodiment, one or more of the CVT unit 122, the air intake system 124, and the exhaust system 126 include a sensor 160 that monitors a characteristic of the air within the respective CVT unit 122, air intake system 124, and exhaust system 126. In the embodiment illustrated, multiple sensors 160 are operationally and communicatively connected to the transmission 130, the wheels 104, the air intake system 124, the exhaust system 126, and the CVT unit 122 to receive signals from at least one of the connected sensors. Exemplary sensors include a temperature sensor, a speed sensor, and a load sensor.In one mode, sensors 160 provide an indication of the air temperature inside the respective CVT unit 122, the air intake system 124, and the exhaust system 126 to an engine control circuit (ECC) 162, which includes a logic component for controlling the operation of the power source 106. When the monitored air temperature exceeds a threshold, the ECC 162 responds by at least one of the following: / nOP iΠ / 77Π7 / B / YILI. - 21 Limiting the output speed of the shaft 120 from the power source 106, limiting the speed of the vehicle 100, and indicating an overheating condition to a vehicle 100 operator through a user interconnect, such as a gauge 164 or a display 165, within the vehicle 100 operator's area. Exemplary user interconnections are described in U.S. Patent Application No. 15 / 161,720, filed May 23, 2016, entitled DISPLAY SYSTEMS AND METHODS FOR A RECREATIONAL VEHICLE, File No. PLR-12-27457-01P-US-E, the full description of which is expressly incorporated by reference. Exemplary indicators of an overheating condition include a light, a warning message on a display 165, or any other means suitable for communicating this condition to an operator.By limiting engine speed or vehicle speed, the air temperature inside the CVT 122 unit is reduced, as is the temperature of the drive belt inside the CVT 122 unit. This reduces the risk of drive belt failure. With reference to Figure 2, an exemplary continuously variable transmission 200 is depicted. The continuously variable transmission 200 includes a drive clutch 202 operatively coupled to shaft 120 of / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 22 output, a driven clutch 204 operatively coupled to the output shaft 128 and a driving band 206 operatively coupled to the driving clutch 202 and the driven clutch 204 to transfer power from the driving clutch 202 to the driven clutch 204. The driving clutch 202 includes a first clutch pulley 208 and a second driving clutch pulley 201 that is movable relative to the first driving clutch pulley 208. The driven clutch 204 includes a first driven clutch pulley 212 and a second driven clutch pulley 214 that is movable relative to the first driven clutch pulley 212. Both the driving clutch 202 and the driven clutch 204 are located within a housing 220 having an interior 222. The housing 220 may consist of multiple components that cooperate to form the housing 220. The multiple components may also include features for directing airflow through the interior 222 of the housing 220. In one example, the housing 220 includes a base having a first opening adapted to receive the driving shaft 120 and a second opening adapted to receive the driven shaft 128, and a cover attached to the base. The cover and the base cooperate to define the interior 222 of the housing 220. The cover and the base may include features / nOP iP / 77P7 / B / YILI - 23 to direct airflow through the interior 222 of the housing 220. As shown in Figure 2, one or more air supply ducts 230 are coupled to the housing 220. The exemplary air supply ducts include hoses. In one embodiment, each air supply duct 230 provides air to the interior 222 of the housing 220 through a respective air supply opening 232 on the exterior 234 of the housing 220. The air supply ducts 230 provide air to the interior 222 of the housing 220 to cool the driving clutch 202, the driven clutch 204, and the driving belt 206. As a result, this configuration provides a cooling effect on the driving belt 206.The supplied air is directed towards one or more of the first driving clutch pulley 208, the second driving clutch pulley 210, the first driven clutch pulley 212, and the second driven clutch pulley 214, where the supplied air will be admitted over the heat to cool the respective one or more of the first driving clutch pulley 208, the second driving clutch pulley 210, the first driven clutch pulley 212, and the second driven clutch pulley 214. The air will then circulate inside the housing 222, potentially or deliberately in contact with one or more of the first / nOP iΠ / 77Π7 / B / YΙΛΙ. - 24 drive clutch pulley 208, the second drive clutch pulley 210, the first driven clutch pulley 212 and the second driven clutch pulley 214 and then exits from the inside 222 of the housing 220 through one or more air exhaust openings 236 in the wall 234 of the housing 220. One or more exhaust or outlet ducts 238 are coupled to the exhaust openings 236. With reference to Figure 3, an exemplary schematic view of a diagnostic system 300 is shown. Included in the diagnostic system 300 is the engine control circuit (ECC) 162, which has a diagnostic circuit (DC) 302. The DC 302 is configured to detect or predict a failure of the CVT drive belt 206 122 based on at least one operating parameter, such as an engine or vehicle parameter or signal. Although the DC 302 is shown within the ECC, the DC may be independent or separate from the ECC or incorporated within any other of the vehicle systems 100 to suit the application. The failure of the 206 drive belt can refer to a deterioration of the drive belt caused by spin burnout or an hourglass formation event. For example, during substantial rotation of the drive pulleys relative to the drive belt, almost / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 25 Stationary, a slippage of the drive belt 206 can generate an hourglass event, changing the lateral profiles of the drive belt 206 into an hourglass shape. As one example only, when the wheels 104 become stuck in a hole or loose soil, such as mud or snow, the motor speed may increase, but the wheel speed may decrease to almost zero. This lack of rotational movement of the wheels 104 can cause the drive shaft 128 to stop and generate an hourglass formation event on the drive belt 206. In the illustrated configuration, the DC 302 is microprocessor-based and includes a non-transient, computer-readable medium or database 304, which contains stored processing instructions executable by the DC 302's microprocessor to control the operation of a CVT 122 diagnostic process. A non-transient, computer-readable medium or memory may include random-access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (e.g., EPROM, EEPROM, or snapshot memory), or any other tangible medium capable of storing information. For example, a predefined calibration of an empirical lookup table might be / nOP iP / 77P7 / B / YILI - 26 stored in volatile or non-volatile memory for subsequent access. The exemplary operating parameters relate to engine speed (e.g., revolutions per minute (rpm)), engine load (e.g., relative load percentage (% RL)), throttle position (e.g., throttle position percentage), engine torque (e.g., inch-pounds or inch-ounces), and engine horsepower, among others. Additional suitable operating parameters are also considered to suit different applications. Detailed descriptions of the exemplary operating parameters and signals are provided in the following paragraphs in relation to Figures 4 through 7. As used herein, the term circuit or unit may refer to, be part of, or include an application-specific integrated circuit (ASIC), an electronic circuit, a processor or microprocessor (shared, dedicated, or pooled), and / or memory (shared, dedicated, or pooled) that executes one or more programs or immutable programs, a combinational logic circuit, and / or other suitable components that provide the described functionality. Thus, although this description includes examples and distributions / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 27 particulars of the circuits, the scope of the present invention should not be considered limited since other modifications will become evident to the expert practitioner. The term "logic component," as used herein, includes a program and / or immutable program that executes, or several circuits. Therefore, depending on the modality, various logic components can be implemented in an appropriate manner and will remain in accordance with the modalities described herein. A machine-readable, non-transient medium comprising a logic component may further be considered to be constituted within any tangible form of a computer-readable carrier, such as solid-state memory, magnetic disk, and optical disk, containing an appropriate set of computer instructions and data structures that can cause the processor to perform the techniques described herein. This description includes other modes in which the DC 302 is not microprocessor-based; rather, it is configured to regulate the operation of the CVT 122 diagnostic process based on one or more immutable instruction settings and / or program instructions stored in database 304. Additionally, the DC 302 can / nOP iΠ / 77Π7 / B / YΙΛΙ - 28 be contained within a single device or may be in a plurality of networked devices joined together to provide the functionality described herein. During the diagnostic process, the DC 302 regulates a general diagnostic operation of the current system 300. In general, the DC 302 monitors at least one of the operating parameters or diagnostic signals of the CVT 122's drive band 206 via a network 306, such as a collective Controller Area Network (CAN) line. Any type of network that has a collection of network-connectable devices, such as computers, servers, and other physical elements interconnected by communication channels, is considered. Example networks include wired or wireless networks, or combinations thereof. Example networks may include Bluetooth-enabled or Wi-Fi-enabled networks. The diagnostic system 300 also includes one or more sensors 160, such as a throttle position sensor 308, an engine torque sensor 310, a temperature sensor 312, an engine load sensor 314, a vehicle speed sensor 316, an engine RPM sensor 318, a fuel sensor 320, and similar sensors. These sensors 160 are operationally connected to the DC 302 via network 306 using / nOP iP / 77P7 / B / YILI - 29 The user interface, such as the calibrator 164 or the display 165, is configured to measure operating characteristics and vehicle conditions 100. During operation, information related to operating parameters and signals is displayed on the display 165, accessible to the user via the network 306. It is envisaged that the user may refer to an operator or any other system associated with the diagnostic system 300. The DC 302 manages the interactions between the user and the DC 302 by means of a human-machine interface (HMI), such as a calibrator interface, a keyboard, a touchpad or display, a mouse, a trackball, a voice recognition system, and the like. The display 165 (e.g., text and graphics) is configured to receive input data from the user and / or the DC 302. In one mode, the user uses an input device, such as the HMI, to interact graphically or via text with the current 300 system. Associated data and / or parameters are typically received by the DC 302 and then transferred to the 165 display via a dedicated or shared communication system, using the 306 network. Additionally, any external database accessible by the DC 302 can also be used as part of the 300 diagnostic system. / nOP ίΠ / 77Π7 / Β / ΥΙΛΙ - 30 With reference now to Figure 3, it is preferred that the DC 302 include a monitoring circuit 322, a detection circuit 324, an alerting circuit 326, a storage circuit 328, and a display circuit 330. Although these secondary circuits 322 to 330 are illustrated as dependent circuits, subordinate to the original DC 302 circuit, each secondary circuit can be operated as a separate unit from the DC, and other suitable combinations of secondary circuits are contemplated to suit different applications. One or more circuits or units can be selectively grouped as a key program model that runs on the processor having the program as service features (SSaS). All relevant information can be stored in database 304, for example, as a non-transient data storage device and / or a machine-readable data storage medium carrying computer-executable instructions, for retrieval by DC 302 and its dependent circuitry. Also included in DC 302 is an interconnection circuit 322 to provide an interconnection between DC 302, database 304, network 306, sensors 160, and vehicle display 165 100. It is preferred that interconnection circuit 332 provide electrical interconnections for / nOP iP / 77P7 / B / YILI - 31 Perform diagnostic operations, for example, on network 306, display 165 and other related system devices, services and applications. Other devices, application services may include, but are not limited to, one or more program components and physical elements, etc., related to the DC 302. The interconnection circuit 332 also receives vehicle-related operating data or parameters 100 from sensors 160 or other related systems, which communicate to the respective circuits such as the DC 302 and its dependent circuits. The monitoring circuit 322 is configured to receive operating data and parameters via the interconnecting circuit 332 and provide operating condition or characteristic information about vehicle 100. Specifically, the monitoring circuit 322 provides detailed information about engine or vehicle conditions, such as temperature, speed, and power of the vehicle 100, in relation to the CVT 122 using the sensors 160. In general, as described in more detail later, the diagnostic system 300 determines its operational characteristics by evaluating the engine or engine operating conditions. The detection circuit 324 is configured to receive data and operating parameters from the 306 / nOP ίΠ / 77Π7 / Β / YΙΛΙ network - 32 by means of the interconnecting circuit 332 and to examine the received operating data and parameters to diagnose the drive belt 206 based on a predetermined set of rules or algorithms. During operation, the detection circuit 324 recognizes or identifies a predetermined triggering event caused by a change in a condition of the CVT 122, the power source 106, and / or the vehicle 100, and identifies or detects the drive belt 206 failure based on the triggering event. Exemplary triggering events are described in the following paragraphs in relation to Figures 4 through 7. The alert circuit 326 is configured to generate an information signal or INFO message to inform the user or other users of the detected triggering event by converting the triggering element into a message with user-recognizable meaning. More specifically, one or more triggering events are transformed by the alert circuit 326 into warning or status signals for the 206 drive belt. Subsequently, the warning or status signals are supplied to the 165 display, a mobile device, or any other computing device to warn the user or other users. It is also contemplated that when the triggering event is detected, the alert circuit 326 provides an option to override user input by adjusting one or more operating parameter values ​​to prevent damage to the 206 drive belt and thus correct the triggering event.Exemplary information signals are described in the following paragraphs in relation to Figures 4 to 7. In one mode, a user input is provided for blocking one or more of the processing sequences described herein to provide the operator with flexibility in vehicle performance. The storage circuit 328 is configured to digitally store relevant information related to the present diagnostic system 300 in database 304. More specifically, database 304 includes operating data and parameters related to analysis data about triggering events for purposes of research, development, improvement of logic components or comparative algorithms, and further investigations by the user or related systems. The presentation circuit 330 is configured to retrieve from database 304 and interactively display an appropriate status or information message associated with the generated INFO signal, based on the triggering event for illustration on screen 165. An instance report / nOP iP / 77P7 / B / YILI - 34, related to each INFO signal and the corresponding triggering event, is generated graphically or textually by the presentation circuit 330 in real time. In one mode, the information is automatically transmitted to a central server, other vehicles, or any other suitable system, as desired. With reference to Figures 4 through 7, exemplary processing sequences for the execution of the present System 300 diagnostic system are illustrated. Although the following steps are described primarily with respect to the modalities in Figures 1 through 3, it should be understood that the steps within the processing sequences can be modified and executed in a different order or sequence without altering the principles of this description. Figure 4 illustrates an exemplary processing sequence of a belt slip event detection logic component of the diagnostic system 300 in a feedback control mode. The belt slip event is one of the triggering events detected by the detection circuit 324. In feedback control mode, when the belt slip element is detected, the alert circuit 326 has an option to notify the user of the failure of the drive belt 206 or to automatically adjust at least one operating parameter for / ñor iP / 77P7 / B / YILI - 35 Remove or reduce the effect of the fault for continuous operation of the vehicle 100 without interruption. In the illustrated configuration, steps 402 and 404 are performed simultaneously, but each step can be performed separately or individually, independently of the others. In step 402, the monitoring circuit 322 receives a signal from each desired vehicle or a parameter from the user, such as a predetermined throttle position parameter, to open and close a throttle control valve for a throttle position sensor 308 or a predetermined engine torque parameter from the engine torque sensor 310. In stage 404, the monitoring circuit 322 receives an environmental condition parameter or signal from the vehicle 110, such as a temperature signal from temperature sensor 312 configured to measure the temperature of the drive belt 206 or the CVT air temperature 122. For example, temperature sensor 312 may be located in the air supply duct 230, the air exhaust duct 238, or directly on or near the drive belt 206 using an infrared sensor. Other exemplary environmental condition signals include an engine manifold temperature, a pressure or vacuum signal, a motion signal, and an acceleration signal. - 36 crankshaft, a transmission gear position signal, a CVT reduction rate signal, a transmission line tension or torque signal, a steering angle signal, a steering frame offset signal, and the like. Additional appropriate environmental condition signals are also considered as needed. For example, in another mode, the monitoring circuit 322 can receive a road load condition, such as rough terrain, loose sand, and the like, by detecting the road load condition using sensor 160 or by receiving a user-entered road load condition to apply it as one of the environmental condition signals. It is preferred that steps 406 and 408 be performed simultaneously, but each step can be performed separately or individually, independently of the other. In step 406, the monitoring circuit 322 receives monitoring of at least one engine-based parameter, such as an engine load signal (e.g., % RL) from engine load sensor 314, a throttle position signal (e.g., a percentage of throttle position) from throttle position sensor 308, or an engine torque signal (by / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 37 example, inch-pounds or inch-ounces) from the engine torque sensor 310. Other exemplary engine-based parameters include an engine power parameter, a transmission speed parameter, a crankshaft rotation or position parameter, an engine control unit (ECU) internal clock parameter, a crankshaft acceleration parameter, and the like, as received from each corresponding sensor 160. In stage 408, monitoring circuit 322 monitors at least one transmission-based parameter, such as the vehicle speed parameter (e.g., miles per hour) from vehicle speed sensor 316 or an engine speed parameter (e.g., RPM) from engine speed sensor 318. Other exemplary transmission-based parameters include parameters received from an infrared sensor, a global location system sensor, a laser sensor, an ultrasonic sensor, a steering angle sensor, a steering rack displacement sensor, a gear position sensor, and the like. Other suitable chassis-based parameters are also considered to suit the application. In stage 410, detection circuit 324 detects the band slippage event based on a comparison of at least one of the parameters based on / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 38 Motor and driveline-based parameters with a predetermined threshold to prevent damage related to the CVT 122 drive belt 206 or a transmission 130 output drive line. Any combination of the motor-based and driveline-based parameters is considered to detect a belt slippage event. For example, when the rotational speed ratio between the drive shaft 120 and the driven shaft 128 is 4:1 and the motor load is 10-20% for a predetermined period of time, e.g., 5 seconds, a belt slippage event is suspected. As another example, when the rotational speed ratio between the drive shaft 120 and the driven shaft 128 is 7:1 and the motor load is approximately 50% or greater for a predetermined period of time, e.g., 1 second, a belt slippage event may be developing.When at least one of the motor-based and driveline-based parameters exceeds a predetermined threshold, the control advances to at least one of stages 412 and 414, depending on the application. Otherwise, the control reverts to stages 402 and 404. For example, only the belt slippage event F (slip) can be defined by a time function and at least one of the motor-based and driveline-based parameters, as provided by / ñor Lñ / zznz / E / YiAi - 39 expression (1): F (slip) = T Farm (1) where T indicates a time period and Farm indicates at least one of the parameters displayed in the engine and driveline-based settings. As an example, the belt slip event can be detected by detection circuit 324 when the engine rpm and driveline speed parameters continuously exceed the predetermined threshold for a predetermined time period while the vehicle is in park or neutral. An example time period can range from 1 second to 5 seconds. It is preferred that steps 412 and 414 be performed simultaneously, but each step can be performed separately or individually, independently of the other. In step 412, the alert circuit 326 generates the INFO information signal based on the detected triggering event, the belt slippage event, to inform the user of the triggering event using display 165. For example, the INFO information signal is displayed using a dashboard light or an audible signal that includes a text or graphic indicator (e.g., a symbol or icon) and display 165. Other suitable auditory, visual, or tactile indicators are also considered. In step 414, the alert circuit 326 / nOP ίΠ / 77Π7 / Β / ΥΙΛΙ Circuit 40 automatically adjusts or modifies at least one of the operating parameters based on a predetermined calibration table (334) or empirical search stored in database 304, such as desired vehicle input parameters, environmental condition parameters, engine-based parameters, or transmission line-based parameters, to avoid or prevent potential CVT or transmission line damage. For example, when detection circuit 324 identifies a belt slippage event, alert circuit 326 automatically reduces engine speed, engine torque, engine load, or throttle valve position percentage by a predetermined value. Other appropriate adjustments or modifications of the operating parameters are contemplated to suit different applications.In one mode, the automatic tuning stage can optionally be ON or OFF, as desired, and a progressive warning system can be used to alert the user of potential damage to the CVT or driveline using a color, hue, and saturation intensity technique. For example, a yellow light might indicate a low-level warning, suggesting the user shift to a lower gear, while a red light might indicate a high-level warning, automatically reducing the load or engine speed to a predetermined value. / nOP ίΠ / 77Π7 / Β / ΥΙΛΙ Figure 5 illustrates an exemplary processing sequence of the diagnostic system 300 belt slip event detection logic component 500 in proactive control mode. In proactive control mode, the diagnostic system 300 proactively notifies the user of a drive belt 206 impediment fault or automatically adjusts at least one operating parameter before potential damage to the CVT or driveline occurs. For example, when the diagnostic system 300 determines that the probability of a fault approaches 90%, the alert circuit 326 automatically adjusts at least one operating parameter to remove or lessen the effect of the vehicle 100 impediment fault, without interruption. In the illustrated configuration, it is preferred that stages 502, 504, and 506 be analyzed simultaneously, but each stage can be performed separately or individually, independently of the others. In stage 502, the monitoring circuit 322 receives the desired vehicle input signal or parameter specified by the user. In stage 504, the monitoring circuit 322 receives the environmental condition parameter or vehicle signal 100. In stage 506, the monitoring circuit 322 monitors at least one transmission line-based parameter. In stage 508, the detection circuit 324 / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 42 detects the belt slippage event based on the comparison of at least one of the user's desired vehicle input signal, the ambient condition signal, and the transmission line-based parameter with the predetermined threshold for detection in a potential related to the CVT drive belt 206 or the transmission output line 130. Any combination of the user's desired vehicle input signal, the ambient condition signal, and the transmission line-based parameter is considered to detect the belt slippage event. For example, when the desired throttle position percentage is at 20%, the rotational speed ratio between the drive shaft 120 and the driven shaft 128 is 4:1, and the engine load is at 10 to 20% for a predetermined time period, for example, 5 seconds, then a belt slippage event is likely to occur.As another example, when the desired regulator valve position percentage is at 50%, the rotational speed ratio between the driving shaft 120 and the driven shaft 128 is 7:1, and the motor load is approximately 50% or greater for a predetermined period of time, for example, 1 second, then a belt slippage event may be imminent. This is due to the probability of a failure of the drive belt 2006 / nOP iP / 77P7 / B / YILI. If 43 is greater than a predetermined threshold (for example, 90%), control advances to at least one of stages 510 and 512, depending on the application. Otherwise, control returns to stages 502, 504, and 506. It is preferred that steps 510 and 512 be performed simultaneously, but each step can be performed separately or individually, independently of the other. In step 510, the alert circuit 326 generates an INFO signal based on the detected belt slip event to inform the user of the impedance failure of the drive belt 206 before potential damage to the belt or transmission line occurs. Similarly, in step 512, the alert circuit 326 automatically adjusts or modifies at least one of the operating parameters before the impedance failure of the drive belt 206 occurs, thus preventing or mitigating potential damage to the CVT or transmission line.For example, the alert circuit 326 automatically reduces the regulating valve position percentage by a predetermined rate (e.g., 10%, thereby reducing the regulating valve position percentage from 50% to 40%) to prevent impedance failure of the drive belt 206. Figure 6 illustrates an exemplary processing sequence of a logic component 600 event detection / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 44 critical belt life event of the diagnostic system 300. The critical belt life event is one of the triggering events detected by the detection circuit 324 and is triggered based on a temperature parameter related to the CVT 122 drive belt 206. Based on the temperature parameter received from temperature sensor 312, configured to measure the temperature of the 206 drive belt or the air temperature of the 122 CVT, detection circuit 324 provides input detection of critical belt life events to prevent overheating of the drive belt. Consequently, the longevity and durability of the 206 drive belt can be increased. In stage 602, the monitoring circuit 322 receives and monitors the environmental condition parameters or signals from sensor 160, such as the temperature signal from temperature sensor 312 configured to measure the temperature of vehicle components, for example the drive belt 206 or the CVT air intake or exhaust system 124,126. For example, the drive belt temperature or a CVT air outlet temperature is measured by one or more temperature sensors 312. In stage 604, monitoring circuit 322 receives and monitors at least one motor-based parameter / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 45 related to the engine load signal, throttle position signal, engine torque signal, engine power signal, or similar. Other exemplary engine-based parameters include parameters related to a clutch ratio, a transmission gear selection or position, an intake pressure, an intake temperature, a transmission line speed, an ECU clock, and similar, as received from each corresponding sensor 160. In stage 606, monitoring circuit 322 receives and monitors at least one transmission line-based parameter, such as the vehicle speed parameter from vehicle speed sensor 316 or the engine speed parameter from engine speed sensor 318. In certain configurations, a wheel speed sensor is also used to monitor the speed parameter. In stage 608, detection circuit 324 detects the critical belt life event based on a comparison of at least one of the motor-based, transmission line-based, and environmental condition parameters with a predetermined threshold to predict the remaining life of the CVT 122 drive belt 206. When at least one of the motor-based, transmission line-based, and environmental condition parameters is greater / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 4 6 that the predetermined threshold, control advances to at least one of stages 612 and stage 614. Otherwise, control returns to stages 602, 604 and 606. As an example only, the critical belt life event F(life) can be defined by a function of time and at least one of the motor-based, transmission line-based, and environmental parameters, as provided by expression (2): F(life) = remaining - T Farm (2) where T indicates a time period, Farm indicates at least one of the parameters based on motor, drive line, and environmental condition, and remaining indicates the remaining belt life of the 206 drive belt. As an example, the critical belt life event can be detected by the 324 detection circuit when the belt temperature exceeds a predetermined threshold (e.g., greater than 121°C (250°F)) continuously for a predetermined time period (e.g., 10 to 15 minutes), or the remaining belt life of the 206 drive belt is less than a minimum belt life threshold. In one mode, the minimum belt life threshold is determined by at least one of a belt temperature, a belt speed, and a belt load. As an example only, when the band temperature is at 121°C (250°F) for 15 minutes, the remaining lifetime period is / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 47 approximately 150 hours, but when the belt temperature is at 166°C (330°F) for 10 minutes, the remaining belt life is approximately 10 hours. The belt temperature (or belt speed or load) and the belt life have an inverse relationship, such as a negative exponential slope on a graph. Therefore, the remaining belt life can also be calculated similarly based on the belt speed and load to suit different applications. Thus, thermal degradation of the drive belt 206 is predicted by the detection circuit 324. In stage 610, when the detection circuit 324 detects that the remaining life of the 206 drive belt is less than the minimum life threshold (e.g., 10% remaining life), the control advances to at least one of stages 612 and 614 (or simultaneously to both stages 312 and 314), depending on the application. Otherwise, the control returns to stages 602, 604, and 606. In stage 612, the alert circuit 326 generates an INFO information signal based on the detected triggering event to inform the user using display 165. For example, the INFO information signal is displayed on the presentation circuit 330 using a light / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 48 of a dashboard or an audible signal that includes a text or graphic indicator (e.g., a °F / °C band of temperature reached (or to be reached), or distance to band failure, % of band life remaining, or % of band life used) on the display 165, request maintenance of the driving belt 206. Other suitable audible, visual, or tactile indicators are also contemplated. In stage 614, the warning circuit 326 automatically adjusts or modifies at least one of the operating parameters, such as environmental condition parameters, engine-based parameters, or transmission line-based parameters, based on calibration table 334 stored in database 304, to prevent or mitigate potential CVT drive belt failure. For example, when the detection circuit 324 identifies a critical belt life event, the warning circuit 326 automatically reduces the vehicle speed by a predetermined value. Other appropriate adjustments or modifications to the operating parameters are contemplated to suit different applications. Figure 7 illustrates an exemplary processing sequence of a logical component 700 for detecting engine crankshaft acceleration variation events in diagnostic system 300. The acceleration variation event of / nOP ίΠ / 77Π7 / Β / YΙΛΙ - The 49 engine crankshaft is one of the triggering events detected by the 324 detection circuit and is activated based on a variation pattern of at least one operating parameter measured over a predetermined period of time. It is assumed that the parameter variation pattern has been monitored and detected based on historical data from a logic component or comparative algorithm. During operation, the engine crankshaft acceleration variation event may be perceived as being caused by a belt slippage event described above, or by an improper ignition sequence event from power source 106. The engine crankshaft acceleration variation event detection logic component 700 distinguishes the belt slippage event from an engine combustion misfire event. Thus, the present method is advantageous in improving the diagnosis of drive belt failure 206 without considering a combustion misfire signal. In stage 702, the monitoring circuit 322 receives and monitors the environmental condition parameter or signal from vehicle 100, such as a fuel status signal (e.g., fuel ON / OFF) from fuel sensor 320 or a / nOP iΠ / 77Π7 / Β / YΙΛΙ - 50 Engine coolant temperature signal from temperature sensor 312. Other exemplary environmental condition signals include a drive belt temperature signal, a clutch status signal, or similar. For example, the clutch status signal can indicate a fully engaged state, a partially engaged state, or a disengaged state. Additionally, a pulley position signal can be used as one of the environmental condition signals. In one mode, the belt slippage event can be ignored within a predetermined tolerance range when the crankshaft acceleration signal is below a predetermined lower threshold. However, the belt slippage event cannot be ignored when the crankshaft acceleration signal is above a predetermined upper threshold (i.e., when the vehicle or engine speed reaches a predetermined threshold) and the vehicle is decelerated from its current speed to a lower speed. If the fuel status signal is OFF during deceleration, an initial predetermined time period may be the optimal timeframe for detecting a belt slippage event. In stage 704, monitoring circuit 322 receives and monitors at least one motor-based parameter / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 51 related to the crankshaft acceleration signal, engine torque signal, transmission gear position signal, or similar. Other exemplary engine-based parameters include parameters related to a clutch ratio, gear selection or position, intake pressure, intake temperature, transmission line speed, ECU clock, and similar, as received from each corresponding sensor 160. In stage 706, monitoring circuit 322 receives and monitors at least one transmission line-based parameter, such as the vehicle speed parameter from vehicle speed sensor 316 or the engine speed parameter from engine speed sensor 318. In one mode, a wheel speed signal received from the wheel speed sensor is also used to monitor the speed parameter. In stage 708, detection circuit 324 detects the engine crankshaft acceleration variation event based on a variation pattern of at least one operating parameter measured over a predetermined time period. For example, the engine crankshaft acceleration variation event is detected by measuring the acceleration or deceleration rate of the crankshaft acceleration signal based on the crankshaft rotation angle (e.g., / nOP ίΠ / 77Π7 / Β / YΙΛΙ every 90°, 180°, or 270°). When a rate of - 52 If the acceleration or deceleration of the crankshaft acceleration signal over a time interval exceeds a predetermined threshold, an initial detection of the variation pattern is recognized by detection circuit 324. In one mode, the rate of acceleration or deceleration over the time interval does not need to be measured across the entire engine. In stage 710, after initial detection of a variation pattern, detection circuit 324 records or stores data related to the variation pattern at a predetermined time interval (for example, on each motor cycle) in database 304 for subsequent comparison. In stage 712, when the frequency of the variation pattern is greater than a predetermined threshold, the variation pattern lasts for a longer period than the predetermined time period, or any combination of the pattern frequency and time period is greater than a predetermined threshold (or time period), control advances to at least one of stages 714 and 716. Otherwise, control returns to stages 702, 704, and 706. As an example only, the engine crankshaft acceleration variation event F(ecav) can be defined by a function of the parameter variation pattern, time period (or frequency) and at least one of the parameters / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 53 based on engine, based on transmission line and environmental, as provided by expression (3): F(ecav) = Pattern (T / Freaq) Farm (3) where pattern indicates a parameter variation pattern, T indicates a time period, Freq indicates a frequency of the parameter variation pattern, and Parm indicates at least one of the condition parameters: engine-based, transmission-line-based, and environmental. In one mode, when a predetermined crankshaft acceleration signal variation pattern is detected and the detected variation pattern lasts for a predetermined time period or repeats a predetermined number of times, the engine crankshaft acceleration variation event is detected by detection circuit 324. For example, when the engine is a zero fuel supply event with a throttle valve off, during a one-second deceleration time period, the engine speed may decrease from 3500 to 2500 rpm.In this case, an undamaged belt will have approximately 100 detectable engine compression strokes or inertially induced crankshaft accelerations or decelerations. In contrast, a belt with a damaged section will have approximately 8 to 30 additional detectable crankshaft accelerations or decelerations. It is preferred that the finned circuit 326 selectively perform stages 714 or 716 based on the / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 54 Application. Specifically, in stage 714, when a single occurrence of an engine crankshaft acceleration variation event is detected, alert circuit 326 performs a first correction method, or rapid correction method, to determine whether the engine crankshaft acceleration variation event is caused by a belt slippage event or an engine combustion misfire event. In one mode, the acceleration or deceleration rate over the time interval is determined based on vehicle speed, transmission status, coolant temperature, and clutch status. Just as an example, when the engine crankshaft acceleration variation event is detected for a shorter period of time (e.g., 2 to 10 milliseconds) and the fuel status signal is OFF or the engine speed is low (e.g., 100 rpm), the engine combustion misfire event does not occur; instead, a belt slippage event takes place. In another mode, when the engine crankshaft acceleration variation event is detected and negative torque is detected—when the engine is producing less torque than required for free movement—the vehicle is decelerated. During deceleration, if the drive belt does not engage, the vehicle will be decelerated. - 55 completely, a belt slippage event is likely to occur. Thus, it is advantageous that the accurate diagnosis of the exact cause of the engine crankshaft acceleration variation event is obtained by a first or quick correction method. In stage 716, when multiple instances of engine crankshaft acceleration variation events are detected, alert circuit 326 performs a second correction method, or slow correction method, to determine whether the engine crankshaft acceleration variation event is caused by a belt slippage event or an engine combustion misfire event. For example, when multiple engine crankshaft acceleration variation events are detected over a longer period of time (e.g., 2 to 60 seconds) (alternatively, the time period could be a couple of minutes) and the engine torque is high during that time, a belt slippage event is occurring, not an engine combustion misfire event.In one mode, the belt slippage event is investigated on scenarios where one of fuel off, low torque, or high torque is identified. During a fuel off scenario, if there is a variation in the crankshaft signal, the acceleration variation event of / nOP ίΠ / 77Π7 / Β / YΙΛΙ is identified. - 56. An engine crankshaft variation is classified as a belt slippage event. During a low torque scenario, if the crankshaft signal magnitude variation exceeds a certain threshold, the engine crankshaft acceleration variation event is classified as a belt slippage event. During a high engine torque scenario, the engine crankshaft acceleration variation event will be classified as an engine misfire event. For example, if the engine crankshaft acceleration variation event cannot be classified as a belt slippage event, it is classified as an engine misfire event. If an engine misfire event is detected, the fuel injector to the misfiring cylinder is deactivated.As with the first correction method, it is advantageous that the accurate diagnosis of the engine crankshaft acceleration variation event is achieved by the second slow correction method. In stage 718, the alert circuit 326 generates the INFO information signal based on the detected triggering event to inform the user using display 165. For example, the INFO information signal is displayed on display 165 to warn the user of the occurrence of a belt slippage event based on / nOP iΠ / 77Π7 / Β / YΙΛΙ - 57 in the detected engine crankshaft acceleration variation events. An example of an engine crankshaft acceleration variation event that is classified as either a belt slippage event or an engine misfire event is provided in Figure 8. Referring back to Figure 8, a logic component 800 for detecting a crankshaft acceleration variation event is provided. Monitoring circuit 322 monitors an engine crankshaft position value with an input from an engine crankshaft position sensor 802, an engine rpm value with an input from an engine rpm sensor 804, and a transmission input shaft rpm value with an input from a downstream rpm sensor 806, as represented by block 810. The exemplary downstream rpm sensors 806 are positioned to determine the rotational speed of a shaft that is ultimately driven by the CVT output shaft, such as a transmission input shaft, a transmission output shaft, a wheel speed sensor, and a half-shaft.If the shaft being monitored by sensor 806 is the output shaft or a gearbox or downstream from a gearbox, a gear position sensor 807 (see figure 8) is also included to indicate the gear ratio of / nOP ίΠ / 77Π7 / Β / YΙΛΙ. - 58 The transmission of gears. Based on the monitored values, detection circuit 324 detects a crankshaft acceleration variation event, as represented by block 812. The crankshaft acceleration variation event is detected by measuring the rate of acceleration or deceleration of the crankshaft signal based on a crankshaft rotation angle (e.g., in rotation increments, e.g., every 1°, 2°, 5°, 10°, 30°, and 90°), which can be determined based on the engine crankshaft position sensor 802 and the engine rpm sensor 804. Exemplary crankshaft acceleration variation events include engine misfire events and damaged CVT belt events, both of which exhibit a repetitive pattern over time. Processing sequence 800 determines an interaction frequency that would be associated with a damaged CVT band, as represented by block 814. Detection circuit 324 monitors for an acceleration or deceleration rate over an observed time interval of the crankshaft acceleration signal, as represented by block 816. If a crankshaft acceleration variation event is detected, the frequency of the observed crankshaft acceleration variation event is compared to the interaction frequency determined for a damaged CVT band by alert circuit 326, as represented by / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 59 Block 818. If the frequency of the observed crankshaft acceleration variation event is within a predetermined threshold of the interaction frequency of a damaged CVT band, the observed crankshaft acceleration variation event is classified as a damaged CVT band event, as depicted in Block 820. Otherwise, the crankshaft acceleration event is classified as an engine misfire event, as depicted in Block 822. In either case, the warning circuit 326 provides the vehicle operator with an indication of this condition. Alternatively, in the event of an engine misfire, the fuel supply to the misfiring cylinder is stopped, or the fuel and spark to the misfiring cylinder are stopped.The supply of fuel or fuel and spark to the cylinder is resumed the next time the vehicle is started with the key. In one mode, the first threshold quantity is an absolute value in hertz, such as 100 hertz. In another mode, the first threshold quantity is a percentage. A typical percentage is within approximately 10 percent above or below the predetermined interaction frequency of the damaged CVT band. In the modes / ñor Lñ / zznz / E / YiAi the frequency of the acceleration event of - 60 crankshaft observed is compared both with the determined interaction frequency of the damaged CVT band as well as a multiple of the determined interaction frequency of the damaged CVT band. With reference to Figure 9, an exemplary processing sequence 840 for determining the interaction frequency of the damaged CVT band is illustrated. The detection circuit 324 detects the engine output speed (Eveve) from the engine rpm sensor 804, represented by block 842, and detects the transmission input speed (Tveve) from the transmission input shaft rpm sensor 806, as represented by block 844. A CVT ratio (CVTrelatio) is determined based on the detected engine output speed and the transmission input speed, as represented by block 846. Based on the determined CVT ratio (CVT ratio) and the detected engine output speed (E speed), a pitch diameter (DP diameter) for the CVT 200 drive clutch 202 is determined, as shown in block 848. The pitch diameter (DP diameter) corresponds to the diameter on the drive clutch 202 that drives the belt 206 when mounted on it. As is understood in the art, the clearance between pulleys 208 and 210 is adjustable, resulting in the drive clutch 202 having multiple pitch diameters. - 61 possibilities. In one example, diagnostic circuit 302 references a lookup table 850 provided in a database 304 to determine the pitch diameter of the drive clutch 202. Diagnostic circuit 302 provides the determined CVT ratio (CVTratio) and the detected engine speed (Evevedad) as inputs to lookup table 850, which returns a pitch diameter (DPdiameter) associated with the provided determined CVT ratio (CVTratio) and the detected engine speed (Evevedad). In one example, diagnostic circuit 302 selects a pitch diameter (DPdiameter) from lookup table 850 that corresponds to the determined CVT ratio (CVTratio) and the detected engine speed (Evevedad). Based on the determined pitch diameter (DPdiameter), diagnostic circuit 302 determines a linear belt speed of the CVT belt 206 (BANDspeed), as presented by block 852. The linear belt speed of the CVT belt 206 (BANDspeed) and a known length of the CVT belt 206 are used by diagnostic circuit 302 to determine an interaction frequency (BANDfreq) of a point on the CVT belt 206 with the drive clutch 202, as represented by block 854. If the CVT belt 206 has a damaged area, the damaged area will interact with the drive clutch 202 at a frequency determined from block 854, which is referenced in / nOP iP / 77P7 / B / YILI - 62 as the interaction frequency of the damaged CVT belt (BANDAfreq). Exemplary belt damage includes twist damage, CVT belt loss, and string breakage. With reference to Figure 10, an exemplary processing sequence 900 is illustrated. The processing sequence 900 adjusts the peak output power of a power source 10 based on a determination that excessive energy is accumulating within the CVT 200. Diagnostic circuit 302 determines an amount of energy introduced into the CVT 200 (Einput), as represented by block 902. Diagnostic circuit 302 further determines an amount of thermal energy exiting the CVT 200 (Esoutput), as represented by block 904. In one mode, the energy introduced into the CVT 200 is determined based on the mechanical efficiencies of the CVT and the mechanical power placed within the CVT 200, while the energy exiting the CVT is determined based on the thermal characteristics of the air flowing through the CVT 200. Diagnostic circuit 302 compares the energy in the CVT 200 (Ein) and the thermal energy leaving the CVT 200 (Eout) to determine if energy is accumulating within the CVT 200, as represented by block 906. Energy accumulating within the CVT 200 results in an increase in the temperature of band 206 of / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 63 the CVT 200. Energy accumulates inside the CVT 200 when (Eoutput) is less than (Einput) · If energy is accumulating within the CVT 200, diagnostic circuit 302 compares the amount of accumulated energy to a threshold level, as represented in block 908. If the amount of accumulated energy exceeds a threshold level, diagnostic circuit 302 reduces the energy input to the CVT 200 (Einput), as represented by block 910, for example, by reducing the peak output power of energy source 106 or the peak output torque of energy source 106. In one mode, the reduction in the peak output power of energy source 106 is gradual to avoid a rapid decline in the peak output power of energy source 106. To reduce the peak output power of power source 106, diagnostic circuit 302 sends a message to the power source 106's ECC 162. An example message is a CAN message over a collective CAN network line. Alternatively, if diagnostic circuit 302 is part of ECC 162, as illustrated in Figure 3, diagnostic circuit 302 directly limits the peak output power of power source 106. / nOP ίΠ / 77Π7 / Β / ΥΙΛΙ With reference to Figure 11, a - 64 exemplary processing sequence 930 to determine an amount of energy in the CVT 200 (Einput). Diagnostic circuit 302 determines the energy source 106, illustratively an internal combustion engine, the output energy level (ENGINEenergy) represented by block 932. In one example, the output energy level (ENGINEenergy) is determined, for instance, by the calculated torque output of the engine multiplied by the engine speed. Diagnostic circuit 302 then retrieves a CVT clutch efficiency (CLUTCHefficiency) from the CVT clutch efficiency map or a lookup table 936, as represented by block 934. The CVT clutch efficiency map has different efficiency values ​​for corresponding output energy levels (MOTORenergy). In one example, diagnostic circuit 302 selects a CVT clutch efficiency (CLUTCHefficiency) from lookup table 93 6 that has the closest corresponding output energy level (MOTORenergy). CVT clutch efficiency is an estimate of the percentage of energy that passes from the driving shaft 120 associated with the CVT 200 to the driven shaft 128 associated with the CVT 200. The remaining energy is assumed to be retained inside the CVT 200 as heat. Diagnostic circuit 302 determines the energy placed in the CVT 200 (Einput) from the product / nOP iP / 77P7 / E / YILI - 65 (ENGINE energy) and the amount of (1 - CLUTCH efficiency) , as represented by block 938. With reference to Figure 12, an exemplary processing sequence 960 is illustrated for determining the amount of power leaving the CVT 200 (Output). Diagnostic circuit 302 determines an air temperature of the air entering the CVT 200 through the air supply ducts 230, as represented by block 962. Based on this temperature reading and a heat transfer coefficient 966, diagnostic circuit 302 determines the amount of power emitted from the CVT 200 (Output) based on the CVT clutch airflow model 968, as represented by block 964. The CVT clutch airflow model is based on engine speed (sensor 804), downstream driveline shaft speed (sensor 806), gear position (sensor 807), and vehicle altitude.The vehicle's altitude can be determined based on barometric pressure measured by a barometric pressure sensor or based on a location value provided by a GPS system. In one mode, the exhaust airflow outlet temperature in duct 238 is also monitored and used to determine the power output from the CVT 200. The detailed description above and the examples described herein have been presented purposefully / nOP ίΠ / 77Π7 / Β / YΙΛΙ - 66 for illustration and description only and not for limitation. For example, the operations described may be performed in any suitable manner. The methods may be performed in any suitable order as long as the operations and results described are still provided. Therefore, these embodiments are intended to cover any and all modifications, variations, or equivalents that fall within the scope of the basic underlying principles described above and claimed herein. Furthermore, although the above description describes physical elements in the form of code executed by a processor, physical elements in the form of a state machine, or a dedicated logic component capable of producing the same effect, other structures are also contemplated. It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

1. A vehicle diagnostic method for a vehicle including an internal combustion engine and a continuously variable transmission (CVT) operatively coupled to the internal combustion engine, characterized in that it comprises the steps of: determining an amount of input energy supplied by the CVT from the internal combustion engine; determining an amount of thermal output energy leaving the CVT; determining, based on the amount of input energy and the amount of thermal output energy, an amount of energy stored in the CVT; comparing the amount of stored energy with a threshold; and reducing the amount of input energy in response to the amount of stored energy satisfying the threshold.

2. The diagnostic method according to claim 1, characterized in that the stage of reducing the amount of energy introduced includes the stage of reducing the energy supplied by the internal combustion engine to the CVT.

3. The diagnostic method according to claim 1 or 2, characterized in that the amount of energy introduced is determined based on the mechanical input characteristics to the CVT.

4. The diagnostic method according to any of claims 1 to 3, characterized in that the amount of thermal energy output is determined based on fluid characteristics of the CVT.

5. The diagnostic method according to any of claims 1 to 4, characterized in that the step of determining the amount of input energy supplied to the CVT by the internal combustion engine includes the steps of: determining an output power of the internal combustion engine; determining a CVT clutch efficiency based on the determined output power; and determining the amount of input energy supplied by the CVT based on the determined output power and the determined CVT clutch efficiency.

6. The diagnostic method according to any of claims 1 to 5, characterized in that the stage of determining the CVT clutch efficiency based on the determined power output includes the stage of retrieving the determined CVT clutch efficiency from the database.

7. The diagnostic method according to any of claims 1 to 6, characterized in that the step of determining the amount of thermal energy output from the CVT includes the steps of: determining an air temperature of the air entering the interior of the CVT; and determining the amount of thermal energy output from the CVT based on a CVT clutch airflow model, a heat transfer coefficient, and the determined air temperature.

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