The present invention generally relates to data acquisition and generation. More particularly, the invention concerns a method and apparatus to obtain, display and manipulate vehicle data obtained from a vehicle network.
Modern vehicles contain several on-board computers that are responsible for the operation, and regulation of many systems such as the engine ignition system, the cruise control system, and the anti-lock brake system, to name but a few. The vehicle computers rely upon multiple sensors to operate the various vehicle systems. These sensors monitor a host of vehicle functions such as engine ignition timing, engine coolant temperature, wheel speed, and other functions. Generally, all of the vehicle's sensors are interconnected by a wired or wireless network. If a problem arises, one or more sensors will report through the network to at least one computer and one of the computers will usually generate a Diagnostic Trouble Code (“DTC”) error message.
Included within the vehicle's computer network is an on-board diagnostic system that stores these DTC's, for later review by a mechanic. On-board diagnostic systems were first installed by vehicle manufacturers in the 1980s. Generally, on-board diagnostic (OBD) systems monitor, control and record various vehicle systems and components. In 1990, Congress amended the Clean Air Act to require the Environmental Protection Agency to mandate and regulate installation of OBD systems in all new vehicles. Subchapter II of the Clean Air Act vests in the federal government the almost exclusive responsibility for establishing guidelines for OBD systems. One state, California, is permitted to establish its own OBD system regulations. As vehicle designs evolve, so have OBD system requirements.
Today, the OBD system standard is OBD-II. Virtually all vehicles built since 1996 have this OBD system, and most vehicle manufactures use one of three computer communication protocols to enable the transfer of DTCs and other vehicle data from the OBD-II system to a scan tool or console. The scan tool connects to the OBD-II system through a federally mandated standardized connector plug that is easily accessible from the passenger compartment.
Most vehicle owners become aware of the OBD system when their “Check Engine Light” display appears on their dashboard. The automobile service industry calls the Check Engine Light a “MIL” or Malfunction Indicator Light. To determine what has caused the MIL, a mechanic attaches a scan tool to the OBD connector, which displays OBD data. Scan tools can range from a simple hand-held meter that provides a simple read-out of the various sensor data or signals, up to a large console unit costing thousands of dollars. These scan tools or consoles are generally compatible with most OBD equipped vehicles and contain software that enables the display of data received from the vehicle's OBD system.
Because of their investment in this equipment, most service shops charge a fee to attach a scanning tool and diagnose the problem that set the MIL. However, with the introduction of more economical and user-friendly scan tools, it is now practicable for the home mechanic and small shop technician to access the OBD system. These scan tools vary widely in the amount and type of data that they can read, with some showing just the basic OBD signals, and others showing the full range of OBD service codes.
While the vast number amateur home mechanics only wish to find out why their Check Engine Light is on, many others want to learn more about their vehicle's performance. However, none of the available scan tools manipulate the data available from the OBD system to obtain vehicle performance. Instead, conventional scan tools simply display data downloaded from the vehicle's OBD system.
Therefore, there exists a need for a device that can display vehicle data obtained from a vehicle network, as well as manipulate the data to provide additional vehicle information for the mechanic or vehicle enthusiast.
In order to overcome the deficiencies with known, conventional scan tools, a system, method and article of manufacture to obtain and display vehicle data is provided. Briefly, the vehicle data display system of the present invention communicates with a vehicle network through a connector located in the vehicle passenger compartment and displays and manipulates the data obtained from the vehicle network.
More specifically, one embodiment of the present invention comprises a computer program product for directing a general purpose digital computer to obtain specific vehicle data from the vehicle network and manipulate the data to obtain a vehicle power. The vehicle power represents a power that is generated at a driving wheel of the vehicle, thereby allowing an enthusiast or technician to obtain a power value that represents the power delivered to the vehicle's driving wheels.
Another embodiment of the present invention comprises a computer program product for directing a general purposes digital computer to obtain data from a vehicle network and manipulate the data to obtain a vehicle torque. The vehicle torque represents a torque generated by the vehicle's engine. Another embodiment of the present invention comprises a computer program product for directing a general purpose digital computer to obtain data from a vehicle network and generate a vehicle fuel economy. Other embodiments of the present invention can use data obtained from a vehicle network to obtain acceleration times over a distance established by a user of the general purpose digital computer as well as specific distances, such as a quarter mile.
These and other features and advantages of the present invention will be appreciated from review of the following detailed description of the invention, along with the accompanying figures in which like reference numerals refer to like parts throughout.
It will be recognized that some or all of the Figures are schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown.
In the following paragraphs, the present invention will be described in detail by way of example with reference to the attached drawings. Throughout this description, the preferred embodiment and examples shown should be considered as exemplars, rather than as limitations on the present invention. As used herein, the “present invention” refers to any one of the embodiments of the invention described herein, and any equivalents. Furthermore, reference to various feature(s) of the “present invention” throughout this document does not mean that all claimed embodiments or methods must include the referenced feature(s).
Modern vehicles contain several on-board computer processors, modules, sensors and other components that are responsible for the operation and regulation of many vehicle systems. Generally, these devices are interconnected by a vehicle network. Most vehicle networks also include an on-board diagnostic system (OBD). OBD systems are in most cars and light trucks on the road today. Through the years, the vehicle network, and the OBD system have become more sophisticated.
One embodiment to the present invention obtains, and manipulates vehicle data from a vehicle network through a connector located in the vehicle passenger compartment. A preferred embodiment of the present invention obtains the vehicle data through an OBD connector.
As defined herein, a “vehicle network” is a group of points or nodes connected by communication paths. Generally, these points or nodes in a vehicle represent modules, sensors or computer processors. These various devices may be joined by a single wire or multiple wires and may be included within one or more discreetly wired networks that either communicate or do not communicate with each other. A vehicle network as defined herein may comprise, in whole or in part, an OBD system employing an SAE J1850 communication protocol, an ISO 9141 communication protocol, or an ISO 9141-2 communication protocol (also known as an ISO 9141 CARB). A vehicle network as defined herein may also employ an ISO 14230 standard, or a KWP 2000 standard. A vehicle network as defined herein may also comprise a Controller Area Network (CAN). The CAN may use ISO 11898, ISO 11519, or other protocols. For example, a vehicle network as defined herein may employ a single wire CAN that uses an SAE J2411 communication standard, a J1939 standard generally found on heavy trucks and buses, a J1708 communication standard or other standards yet to be developed. For example, the vehicle network as defined herein may also employ architectures and communication protocol standards yet to be developed, such as an Intelligent Transportation Systems Data Bus (IDB), or an OBD-III or an OBD-IV standard. A vehicle network as defined herein may employ an IDB communication protocol standard such as J2355, J2366, J2367 and J2368.
An OBD system, as defined herein, may have the capabilities and may perform the functions as proscribed by the United States Code of Federal Regulations (CFR) Title 40 CFR Section 86.094-17, which is referred to and incorporated herein in its entirety by this reference. In addition, an OBD system, as defined herein, may have the capabilities and may perform the functions as proscribed by the California Code of Regulations (CCR) Title 13 Section 1968.1, which is referred to and incorporated herein in its entirety by this reference. In addition, an OBD system, as defined herein, may also have additional capabilities and may perform additional functions not described in the above-incorporated documents.
A preferred embodiment of the present invention is configured to communicate with an OBD-II system. Currently, there are three basic OBD-II protocols in use, each with minor variations on the communication pattern between the OBD computer and the scan console or tool. For example, Chrysler products and most European and Asian vehicles generally use ISO 9141 standard protocols (CHRYSLER is a trademark of Daimler Chrysler of Auburn Hills, Mich.). General Motors vehicles generally use SAE J1850 VPW (variable pulse width modulation) and Ford vehicles generally use SAE J1850 PWM (pulse width modulation) communication protocols (GENERAL MOTORS is a trademark of General Motors Corporation of Detroit, Mich., and FORD is a trademark of Ford Motor Company of Dearborn, Mich.).
The SAE J1850 communications protocol was officially adopted by SAE as the standard protocol for in-vehicle networks in 1994. Today, SAE J1850 is implemented in a variety of production vehicles for diagnostics and data sharing purposes. For example, the SAE J1850 communication protocol enables an inter-module, or inter-sensor data communication network for the sharing of information passed in frames, or messages, between all vehicle electronic modules, nodes and sensors connected to a common bus.
Similarly, ISO 9141 is another communication protocol used in an inter-module, or inter-sensor data communication network for the sharing of information passed in frames, or messages, between all vehicle electronic modules, nodes and sensors connected to a common bus. It employs a serial data communication bus between the vehicle's nodes, modules or sensors and the scan tool. As mentioned above, most European and Asian manufactured vehicles use the ISO 9141 communication protocol.
Most vehicles manufactured since 1996 include an OBD connector located in the passenger compartment area. The OBD connector connects to the vehicle network and can be used to obtain vehicle data. For example, when a “Check Engine Light” indicator appears on a vehicle dashboard the vehicle owner takes the vehicle to a local service station. The mechanic or technician connects a scan tool to the OBD connector in the passenger compartment and obtains a Diagnostic Trouble Code (DTC) that set off the “Check Engine Light” indicator. The technician can then determine a course of action to fix the component that set the DTC. For example, a DTC may be set when the vehicle ECU, or computer processor, no longer receives data from an oxygen sensor or receives data indicating that a fuel injector is misfiring. Conventional scan tools used by today's technicians to obtain vehicle data simply display the data obtained from the vehicle OBD system. Conventional scan tools do not manipulate the vehicle data to generate additional data not provided by the OBD system or the vehicle network.
The present invention provides software programs, or computer readable program code to manipulate data obtained from a vehicle network. One embodiment of the present invention provides software programs or modules to generate data relating to several aspects of vehicle performance, such as vehicle power, vehicle torque, vehicle fuel economy and vehicle acceleration and deceleration. The software program may be stored or placed on a compact disk, a floppy disk, a memory module such as a flash memory device and may also be stored on a general purpose computing device and may be accessed and/or downloaded via a global computer network such as the Internet.
The present invention contemplates the use of personal digital assistants (PDAs), laptops, hybrid phone/PDAs and other general purpose digital computers to obtain data from a vehicle network or OBD system. The various general purpose digital computers will employ one or more software programs or modules to obtain and manipulate vehicle data received from the vehicle network.
With the proliferation of small, powerful computers such as Personal Digital Assistants (PDA's), technicians, mechanics and vehicle enthusiasts will be able to employ these devices instead of conventional scan tools to obtain, and manipulate data from the vehicle network. In addition, laptop computers, hybrid phone/PDA units, electronic organizers, electronic notepads, and hand-held computers can also be employed to obtain and manipulate data from the vehicle network. For example, any number of different PDA platforms such as a PALM, HANDSPRING, TRW, SONY, HEWLETT-PACKARD, COMPAQ, SHARP, NEC or other PDA platforms can be employed to obtain data from the vehicle network or OBD system (PALM is a trademark of Palm, Inc., of Santa Clara, Calif.; HANDSPRING is a trademark of Handspring, Inc., of Palo Alto, Calif.; TRW is a trademark of TRW, Inc., of Cleveland, Ohio; SONY is a trademark of Sony Corporation of Tokyo, Japan; HEWLETT-PACKARD is a trademark of Hewlett-Packard Company of Palo Alto, Calif.; COMPAQ is a trademark of Compaq Computer Corporation of Houston, Tex.; SHARP is a trademark of Sharp Corporation of Osaka, Japan; NEC is a trademark of NEC Corporation of Tokyo, Japan). One skilled in the art will appreciate that the present invention can be employed on virtually any type of device containing a general purpose digital computer.
A preferred embodiment of the present invention employs a PDA to obtain and manipulate data obtained from an OBD-II system. The data may be generated by any vehicle computer processor, electronic control unit, module or sensor. For example, the present invention may obtain and manipulate data relating to fuel and air metering, mass or volume air flow, intake air temperature, engine coolant temperature, throttle/pedal position, O.sub.2 sensor function(s), fuel temperature, fuel rail pressure, engine oil temperature, injector circuit function(s), fuel pump function(s), engine speed, crankshaft position, ignition coil function(s), fuel level, exhaust pressure, vehicle speed, engine oil pressure, power steering function(s), cruise control system function(s), transmission function(s), among others.
Referring to
An OBD interface 20 comprises a wire cable having an OBD coupler configured to removably attach to the vehicle OBD connector 15. The OBD interface 20 also includes a RS232 connector, or other suitable connector that is sized to couple to a protocol converter 25.
The protocol converter 25 includes a general purpose computing device such as an RISC microcomputer or other suitable general purpose computing devices, as well as other commercially available components, that perform interface functions for interfacing the display unit 35 with the vehicle network. The protocol converter 25 includes one or more software modules, or computer readable program codes to communicate with a variety of vehicle network, or OBD communication protocols, such as ISO 9141-2, SAE J1850 (VPW or PWM) or other OBD or other vehicle network protocols. For example, the protocol converter 25 may establish a connection with a vehicle OBD-II system employing a SAE J1850 VPW communication protocol. Once a connection is established, the protocol converter 25 waits for the user of display unit 35 to send a request for OBD-II data.
However, the display unit 35 will send a data request using a RS232 system communication protocol. The protocol converter 25 must then convert the RS232-formatted request into a format recognized by the vehicle OBD-II system. Once the request is converted from the RS232 communication protocol to the OBD-II communication protocol, the protocol converter 25 transmits a command to retrieve the specific OBD-II data, such as throttle position, oxygen sensor status or wheel speed. When the OBD-II data is obtained, the protocol converter 25 then reverses the protocol conversion sequence, and converts the data, which is formatted in an OBD-II communication protocol, to a RS232 communication protocol format. In this fashion, the display unit 35 can communicate with a vehicle network to obtain vehicle data. The necessary components and software used to construct a protocol converter 25 can be located at several places on the Internet.
The protocol converter 25 couples to the display unit 35 through a data cable 30. The data cable 30 may include an RS232 connector for removably coupling to the protocol converter 25, and a universal connector, or other suitable connector for removably coupling to a universal connector port on the display unit 35.
Other cable and connector arrangements may be employed to couple the protocol converter 25 and the display unit 35 to the vehicle OBD connector 15. For example, a male-male, null modem adapter may be employed to connect the display unit 35 to the protocol converter 25. Alternatively, a serial adapter comprising an RS232 plug and a universal connector plug may be employed to connect the display unit 35 to the protocol converter 25. One skilled in the art will appreciate that other arrangements of data cables 30, interfaces 20, and other plugs and cables can be employed to connect the display unit 35 to the vehicle OBD connector 15.
A preferred embodiment of the present invention employs a display unit 35, such as a PDA to display and manipulate vehicle data obtained from the vehicle network or OBD system. In contrast to conventional vehicle data display systems, the present invention manipulates the vehicle data to generate new vehicle performance data, such as vehicle power, vehicle torque, vehicle fuel economy and vehicle acceleration. This vehicle information may then displayed numerically and graphically on the display unit 35.
Referring to
Vehicle manufacturers generally provide a vehicle engine horsepower number. However, this number is not representative of the actual horsepower that is delivered to the driving wheel or wheels of the vehicle because the vehicle engine must first transfer power through the transmission which then transfers the power through a drive shaft which then transfers the power through a ring-and-pinion gear set which then transfers the power through half-shafts which then transfer the power to the driving wheel(s). Each time the power is transferred from one device to the next, some power is lost and the actual horsepower generated at the driving wheel(s) can be as much as 10 to 20% less than that generated by the vehicle engine.
The present invention, using data obtained from the vehicle network, can calculate a horsepower available at a vehicle's driving wheel(s), herein referred to as vehicle power. Once the vehicle power, or driving wheel power is obtained, an available vehicle engine torque can also be obtained. Obtaining the driving wheel power and the vehicle engine torque quickly and easily can help a vehicle operator to determine whether a change to a vehicle system has improved the vehicle's performance. For example, after installing a high-flow air filter, high-voltage ignition coil or other performance-enhancing device, a vehicle owner can then employ the present invention and determine whether the vehicle power or vehicle torque has increased. Prior to the present invention, a vehicle power or vehicle torque would be obtained by testing the vehicle on a dynamometer, or other device. One feature of the present invention is that vehicle data, such as vehicle power and vehicle torque, can be quickly determined by using data obtained from the vehicle network.
A software module or computer readable program code constructed according to the present invention for determining a vehicle power using data obtained from a vehicle network will now be explained. Power is the rate of doing work or the amount of work done in a unit time. Work is the transfer of energy, and an amount of work done is equal to the force applied multiplied by the distance traveled in the direction of that force. Therefore,
Work=(Force)(Distance Traveled)
Because power is the rate of doing work or the amount of work done in a unit time, the power produced is the work done divided by the time taken:
From the power equation listed above, force can be determined because force is equal to the product of mass and acceleration:
Force=(Mass)(Acceleration)
Acceleration is the rate of change of velocity (speed) or the average increase of velocity in a unit of time, usually expressed in feet per second:
Where V2 is an end velocity, V1 is an initial velocity, T2 is an end time and T1 is an initial time. The distance traveled can be obtained by finding the quotient of the change in velocity and twice the amount of time required for the change in velocity:
Where V2 is an end velocity, V1 is an initial velocity, T2 is an end time, and T1 is an initial time.
When these equations are combined, an equation for determining a vehicle power, or driving wheel power is arrived at:
Where m is the vehicle weight, V2 is an end velocity, V1 is an initial velocity, T2 is an end time, and T1 is an initial time. The unit for Power in this equation is kilowatts. Kilowatts can be converted to horsepower by dividing kilowatts by 1.34. The resulting horsepower number is the horsepower available at the vehicle's driving wheel(s).
One feature of the present invention is that the above-described vehicle power software module must only obtain the end velocity V2, the initial velocity V1, the end time T2, and the initial time T1, to generate a vehicle power. The user will input the vehicle mass, or weight.
A preferred embodiment of the power software module may also use data related to the frontal area of the vehicle to generate a vehicle power. Specifically, the vehicle power number generated by the above-described power software module will be more accurate if the force that is used to overcome aerodynamic drag is also include in the vehicle power calculation. Vehicle frontal area, or cross-sectional area is the area of the front profile of the vehicle. The frontal area is component of the power loss due to aerodynamic drag. That is, engine power is required to overcome the drag caused by forcing a vehicle though the air, and the power required increases as vehicle speed increases.
One embodiment of the present invention may include a list, such as: small car, compact, sedan, sport-utility vehicle, and truck. The user will choose the appropriate vehicle type, and the vehicle power software will apply a correction factor and reduce the vehicle power number, to reflect the engine power lost to overcome aerodynamic drag.
Another embodiment of the power software module may employ an altitude correction factor. Engine power decreases as altitude increases, because air density decreases as altitude increases. One embodiment of the present invention may allow a user to input the altitude. An appropriate correction factor may then be included in the vehicle power calculation performed by the power software module.
Yet another embodiment of the power software module may include a tire rolling resistance correction factor. Each vehicle tire has a rolling resistance, and an amount of engine power is required to overcome the total amount of rolling resistance generated by all of the vehicle's tires. One embodiment of the present invention may allow a user to input a tire rolling resistance, or a list of tire rolling resistance values may be presented, and the user will be able to select from the list. For example, the list may present a selection of tire sizes, the user will select a tire size, and the power software module will apply a tire rolling resistance correction factor appropriate for the chosen tire size.
Another embodiment of the present invention may include an actual vehicle engine horsepower software module. This software module will calculate an approximation of the horsepower generated by the vehicle engine. As discussed above, the power delivered to the driving wheels of the vehicle is 10 to 20% less than the power generated by the engine. The actual vehicle engine horsepower software module will include several correction factors to generate a close approximation of the actual power generated by the vehicle engine. For example, the actual vehicle engine horsepower software module may have the user select either a stick-shift transmission or an automatic transmission, and may also have the user select either a front-wheel drive or a rear-wheel drive. Correction factors for each type of vehicle configuration will be included in the actual vehicle engine horsepower software module, which will use the information to generate a vehicle engine horsepower.
Referring to
An operator wishing to obtain a vehicle power will initiate the software module by using a stylus or other object and strike or contact the run button 40. At that instant, the initial time T1 is set and the vehicle is preferably accelerated at maximum acceleration until the user strikes the stats button 45 stopping the test and setting the end time T2. The software module obtains the vehicle's initial velocity V1 at the initial time T1 and obtains the vehicle's end velocity V2 at the end time T2. The initial velocity V1 and end velocity V2 are obtained by accessing the vehicle network through the OBD connector in the passenger compartment. The software module then obtains the difference between the initial velocity V1 and the end velocity V2 and also obtains the total elapsed time, which is the difference between T2 and T1, and calculates the vehicle power, which represents the available horsepower at the vehicle's driving wheel(s). A power curve 50 is graphically displayed on the display unit 35 as shown in
Once the vehicle power has been determined, a vehicle torque can also be obtained by the following equation:
Where RPM is the engine revolutions-per-minute.
The software module then calculates the vehicle engine torque by using the above equation, and displays a torque curve 55 as shown in
Referring to
For example, referring to
Also shown in
Another function of the acceleration software module is the manipulation of vehicle data obtained from a vehicle network to obtain a ¼ mile data. If a user wishes to obtain data on vehicle performance over a ¼ mile, the ¼ mile button 105 is designated. The user then designates the ¼ mile record button 110 to start the test. The acceleration software module then obtains an initial time T1 from the display unit 35 when the vehicle starts moving. Specifically, the acceleration software module accesses the vehicle network to determine when the vehicle starts moving. For example, the data may be obtained from a vehicle wheel speed sensor. When the vehicle begins to move, the acceleration software module obtains the initial time T1 from the display unit 35.
The acceleration software module then continues to obtain data from the vehicle network and when the vehicle has traveled a quarter mile, the acceleration software module obtains an end time T2. The acceleration software module then obtains a difference between the end time T2 and the initial time T1 and displays this time difference in the Time/sec box 115. The acceleration software module also obtains the vehicle speed at the point the vehicle traveled the ¼ mile distance and displays that in the Speed/mph box 120. The user then can choose to save this specific ¼ mile test by designating the ¼ mile save button 125. The data is then saved in the display unit 35. One feature of the present invention is that a user can review and compare different ¼ mile tests to determine changes in vehicle performance.
Another function of the acceleration software module is the breaking, or stopping distance, function also illustrated in
Alternative embodiment software modules may include the capability for the user to enter different stopping distances or different time-to-speed numbers so the user can choose the exact distance or exact speed from which to obtain data.
Referring to
As shown in
Thus, it is seen that a vehicle data display system and method is provided. One skilled in the art will appreciate that the present invention can be practiced by other than the above-described embodiments, which are presented in this description for purposes of illustration and not of limitation. The description and examples set forth in this specification and associated drawings only set forth preferred embodiment(s) of the present invention. The specification and drawings are not intended to limit the exclusionary scope of this patent document. Many designs other than the above-described embodiments will fall within the literal and/or legal scope of the following claims, and the present invention is limited only by the claims that follow. It is noted that various equivalents for the particular embodiments discussed in this description may practice the invention as well.
This application claims priority under 35 U.S.C. §120 and 35 U.S.C. §121 as a divisional of U.S. patent application Ser. No. 10/218,372, filed Aug. 13, 2002, entitled “Vehicle Data Display System and Method.”
Number | Date | Country | |
---|---|---|---|
Parent | 10218372 | Aug 2002 | US |
Child | 11640695 | Dec 2006 | US |