Abstract:
The invention features a method and apparatus for remotely characterizing a vehicle&#39;s emissions performance. The method features the steps of: i) generating data representative of the vehicle&#39;s emissions performance with at least one microcontroller disposed within the vehicle; ii) transferring the data through an OBD, OBD-II or equivalent electrical connector to a data collector/router that includes a microprocessor and an electrically connected wireless transmitter; iii) transmitting a data packet representing the data with the wireless transmitter over an airlink to a wireless communications system and then to a host computer; and iv) analyzing the data packet with the host computer to characterize the vehicle&#39;s emissions performance.

Description:
RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 09/776,033, filed Feb. 1, 2001, now U.S. Pat. No. 6,604,033, the contents of which are incorporated herein by reference, which claims the benefit of U.S. provisional patent applications Ser. Nos. 60/222,152, filed Aug. 1, 2000, 60/222,213, filed Aug. 1, 2000, and 60/220,986, filed Jul. 25, 2000, the contents of which are incorporated herein by reference. 
     In addition, this application is related to the following U.S. Patent Applications that were filed on the same day as the present application: (1) U.S. patent application Ser. No. 09/776,106 entitled “Wireless Diagnostic System for Vehicles” with inventors Bruce Lightner, Diego Borrego, Chuck Myers, and Larkin H. Lowrey and (2) U.S. patent application Ser. No. 09/776,083 entitled “Wireless Diagnostic System for Characterizing One or More Vehicles&#39; Mileage, Fuel Level, and Period of Operation” with inventors Matthew J. Banet, Bruce Lightner, Diego Borrego, Chuck Myers, and Larkin H. Lowrey both of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to the use of wireless communications and diagnostic systems in automotive vehicles. 
     BACKGROUND OF THE INVENTION 
     The Environmental Protection Agency (EPA) requires vehicle manufacturers to install on-board diagnostics (OBD) for emission control on their light-duty automobiles and trucks beginning with model year 1996. OBD systems (e.g., computer, microcontrollers, and sensors) monitor the vehicle&#39;s emission control systems to detect any malfunction or deterioration that causes emissions to exceed EPA-mandated thresholds. Such a system, for example, is an oxygen or nitrogen-sensitive sensor located in the vehicle&#39;s exhaust manifold and tailpipe. 
     The EPA requires that all information monitored or calculated by OBD systems is made available through a standardized, serial 16-cavity connector referred to as the ALDL (Assembly Line Diagnostic Link) or OBD connector. All physical and electrical characteristics of this connector are standard for all vehicles sold in the United States after 1996. The EPA also mandates that, when emission thresholds are exceeded, diagnostic information characterized by OBD systems must be stored in the vehicle&#39;s central computer so that it can be used during diagnosis and repair. 
     A second generation of OBD systems, called OBD-II systems, monitor emission performance and a wide range of additional data that indicate the performance of the host vehicle. For example, in addition to emissions, OBD-II systems monitor vehicle speed, mileage, engine temperature, and intake manifold pressure. OBD-II systems also query manufacturer-specific data, such as engine-performance tuning parameters, alarm status, and properties relating to entertainment systems. In total, OBD-II systems typically access hundreds of segments of data relating to the performance and make of the host vehicle. 
     In addition to the OBD-II systems, most vehicles manufactured after 1996 have electronic control units (ECUs) that control internal electromechanical actuators. Examples include ECUs that control fuel-injector pulses, spark-plug timing, and anti-lock braking systems. Most ECUs transmit status and diagnostic information over a shared, standardized electronic buss in the vehicle. The buss effectively functions as an on-board computer network with many processors, each of which transmits and receives data. The primary computers in this network are the vehicle&#39;s electronic-control module (ECM) and power-control module (PCM). The ECM typically accesses sensors and microcontrollers that monitor or control engine functions (e.g., the cruise-control module, spark controller, exhaust/gas recirculator). The PCM typically controls or monitors ECUs associated with the vehicle&#39;s power train (e.g., its engine, transmission, and braking systems). 
     When a vehicle is serviced (e.g., for an emissions or ‘smog check’), data from the standardized buss can be queried using external engine-diagnostic equipment (commonly called ‘scan tools’) that connect to the above-described 16-cavity electrical connector (called an ‘OBD-II connector’ for vehicles made after 1996). The OBD-II connector is typically located under the vehicle&#39;s dashboard. Data transferred through the connector to the scan tool includes data like that described above as well as ‘diagnostic trouble codes’ or ‘DTCs’ that identify a specific malfunctioning component of the vehicle. This makes the service process more efficient and cost-effective. 
     Some manufacturers include complex electronic systems in their vehicles to access and analyze the above-described data. These systems are not connected through the OBD-II connector, but instead are wired directly to the vehicle&#39;s electronic system. This wiring process typically takes place when the vehicle is manufactured. In some cases these systems transmit data through a wireless network. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the present invention to address the limitations of the conventional engine-diagnostic systems discussed above. Specifically, it is an object of the invention to both access and send data relating to emissions over a vehicle&#39;s ODB-II connector using a remote, wireless system that connects to the Internet. The data are then analyzed and used to monitor the vehicle&#39;s emissions output. This allows, for example, a remote, on-line emissions check for the vehicle that is done completely over the Internet. 
     In one aspect, the invention features a method and apparatus for remotely characterizing a vehicle&#39;s exhaust emissions. The method features the steps of: 1) generating data representative of the vehicle&#39;s emissions with at least one sensor disposed within the vehicle; 2) transferring the data through to a data collector/router that includes: i) a microprocessor; and ii) a wireless transmitter in electrical contact with the microprocessor; and 3) transmitting a data packet representing the data with the wireless transmitter over an airlink to a wireless communications system and then to a host computer. 
     “Data representative of the vehicle&#39;s emissions”, as used herein, means data that can be analyzed or processed to infer, estimate, or predict the emissions of a particular vehicle. “Emissions” means gaseous forms of the following compounds: hydrocarbons, oxides of nitrogen, carbon monoxide, or derivatives thereof. 
     In some embodiments the data can be transferred directly from the ECM/PCM to the data collector/router (i.e., the data collector/router is embedded in the vehicle). Alternatively the data is serially transferred through an OBD-II connector or an equivalent serial interface located within the vehicle to the data collector/router. In this case, “equivalent serial interface” means any interface or connector that allows data to be queried from the vehicle&#39;s ECM. In this case, the data collector/router is typically located underneath the vehicle&#39;s dash. In both cases, the generating step includes generating emissions data using one or more sensors (typically located in the vehicle&#39;s exhaust manifold or tailpipe) that produce a signal in response to gas containing oxygen, oxides of nitrogen, or hydrocarbons. 
     The method also features the step of analyzing the data packet with the host computer to characterize the vehicle&#39;s emissions performance. In this case, the analyzing step features the step of extracting data from the data packet corresponding to the vehicle&#39;s emissions and storing the data in a computer memory or database. Once in the database, the data can be processed with an algorithm, such as a mathematical algorithm that predicts or estimates the emissions (e.g., an estimate of the concentration or amount of oxygen, oxides of nitrogen, or hydrocarbons) from the vehicle. 
     The analyzing step can also include the step of comparing the data with data collected at an earlier time to characterize the emissions performance of the vehicle. For example, the data can be compared to a predetermined numerical value or collection of values that represent ‘acceptable’ exhaust emissions. After the comparison, the method can further include sending an electronic text, data, or voice message to a computer, cellular telephone, or wireless device. The message describes a status of the vehicle&#39;s emissions. In a related embodiment, the vehicle&#39;s emissions status is displayed directly on a page on the Internet or World-wide web. 
     In still another embodiment, the method includes the step of sending a second data packet from the host computer system over an airlink to the wireless communications system and then to the data collector/router disposed in the vehicle. In this case, the second data packet is processed by the microprocessor in the data collector/router to generate a signal, and the signal is sent to at least one microcontroller disposed within the vehicle. The signal, for example, can be processed by the microcontroller and used to adjust one or more of its properties. For example, the signal can be used to ‘clear a DTC’ (i.e., change the DTC&#39;s state from active to inactive) in the vehicle&#39;s ECM. 
     In the above-described method, the terms ‘microcontroller’ and ‘microprocessor’ refer to standard electronic devices (e.g., programmable, silicon-based devices) that can control and/or process data. “Airlink” refers to a standard wireless connection (e.g., a connection used for wireless telephones or pagers) between a transmitter and a receiver. 
     Also in the above-described method, steps i)-iv) can be performed at any time and with any frequency, depending on the diagnoses being performed. For a ‘real-time’ diagnoses of a vehicle&#39;s engine performance, for example, the steps may be performed at rapid time or mileage intervals (e.g., several times each minute, or every few miles). Alternatively, other diagnoses (e.g., a conventional emissions check) may require the steps to be performed only once each year or after a large number of miles are driven. Similarly, steps i)-iii) (i.e. the ‘generating’, ‘transferring’, and ‘transmitting’ steps) may be performed in response to a signal sent from the host computer to the vehicle. Alternatively, the vehicle may be configured to automatically perform these steps at predetermined or random time intervals. In another embodiment, a vehicle&#39;s emissions can be continually monitored, and the vehicle&#39;s owner is only notified when the vehicle ‘fails’ the emissions test. In any embodiment described herein involving ‘passing’ or ‘failing’ an emissions test, the definition of ‘pass’ or ‘fail’ is determined by the appropriate regulating body, e.g. California Air Resources Board (‘CARB’) or an equivalent state-wide organization, the Environmental Protection Agency (‘EPA’), or a similar organization. 
     The invention has many advantages. In particular, wireless transmission of a vehicle&#39;s emissions data makes it possible to remotely identify potential problems and perform ‘on-line emissions checks’ without bringing the vehicle to a conventional service center. In certain situations, this means potential problems with a vehicle&#39;s emissions system can be rapidly determined, or in some cases remotely predicted and addressed before they actually occur. Moreover, emissions data from the vehicle can be queried and analyzed frequently and in real-time (i.e., while the vehicle is actually in use) to provide a relatively comprehensive diagnosis that is not possible in a conventional service center. 
     The device used to access and transmit the vehicle&#39;s data is small, low-cost, and can be easily installed in nearly every vehicle with an OBD-II connector in a matter of minutes. It can also be easily transferred from one vehicle to another, or easily replaced if it malfunctions. 
     Communication with the vehicle&#39;s OBD buss can also be bi-directional, making it possible to actually remotely address problems with the vehicle&#39;s emissions system. For example, DTCs related to the vehicle&#39;s emissions system can be cleared remotely. 
     Another advantage of the invention is that emissions data transmitted from a particular vehicle over a wireless airlink can be accessed and analyzed through the Internet without the need for expensive diagnostic equipment. Software used for the analysis can be easily modified and updated, and then used by anyone with access to the Internet. This obviates the need for vehicle service centers to upgrade diagnostic equipment for next-generation vehicles. The resulting data, of course, have many uses for vehicle owners, surveyors of vehicle emission performance (e.g., the EPA or J.D. Power), manufacturers of vehicles and related parts, and vehicle service centers. 
     Sophisticated analysis of the above-mentioned data yields information that benefits the consumer, vehicle and parts manufacturers, vehicle service centers, and the environment. 
     These and other advantages of the invention are described in the following detailed disclosure and in the claims. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The features and advantages of the present invention can be understood by reference to the following detailed description taken with the drawings, in which: 
     FIG. 1 is a schematic drawing of a wireless diagnostic system in wireless contact with a system of vehicles and the Internet; 
     FIG. 2 is a screen capture of an emissions data file generated using the wireless diagnostic system of FIG. 1; 
     FIG. 3 is a schematic diagram describing how the emissions data file of FIG. 2 is processed to determine emissions data from a vehicle once the data is received by a host computer system of FIG. 1; 
     FIG. 4 is a schematic drawing of a data collector/router used in each of the vehicles of FIG. 1; 
     FIG. 5 is a schematic, top view of a vehicle&#39;s exhaust manifold that features oxygen sensors and a catalytic converter; 
     FIGS. 6A and 6B are graphs showing, respectively, the output of the oxygen sensors before and after a ‘good’ catalytic converter shown in FIG. 5; 
     FIGS. 6C and 6D are graphs showing, respectively, the output of the oxygen sensors before and after a ‘bad’ catalytic converter shown in FIG. 5; and 
     FIG. 7 is a flow chart describing analysis of data transmitted by the data collector/router by the host computer of FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a wireless diagnostic system  10  that communicates with a collection of vehicles  30  using a host computer system  12  and a standard wireless communications system  15 . The diagnostic system  10  remotely characterizes the vehicles&#39; emissions. The wireless communication system  15  is, e.g., a conventional wireless network, e.g. Bell South&#39;s Mobitex network. Each vehicle  32   a ,  32   b ,  32   n  in the collection of vehicles  30  features a data collector/router  35   a ,  35   b ,  35   n  that queries emissions data generated by each vehicle&#39;s ECU and OBD-II systems through an OBD buss. After the query, each data collector/router  35   a ,  35   b ,  35   n  receives emissions data from the host vehicle  32   a ,  32   b ,  32   n  and sends it as a data packet over a wireless airlink  38  to the wireless communication system  15 . The wireless communication system  15  features a standard hardware component  19  (e.g. a system of base stations, computers, and switching and routing hardware) and software component  17  (e.g., software for controlling the above-mentioned hardware) that relay the data packet through a network connection (e.g., a digital line)  40  to the host computer system  12 . 
     A data collection/transmission module 20 (e.g., a high-speed modem) in the host computer system  12  receives the data packet, which is then processed by a microprocessor  21 . The microprocessor controls a data-analysis module  22  (e.g., hardware and software for statistical analysis) that analyzes the data packet to characterize the emissions of each vehicle. The host computer system  12  also includes a data-memory module  25  (e.g., a computer memory or database) that stores the data. A web server  26  receives the processed emissions data from the data-analysis  22  and data-memory modules  25  and makes, it available to an Internet computer network  50  through a first network connection  52 . An end-user  56  accesses the data on the web server  26  through a second network connection  54  using the Internet computer network  50 . 
     Data packets from each data collector/router  35   a ,  35   b ,  35   n  can also be accessed directly over an airlink  70  by wireless telephones  62   a ,  62   b ,  62   n  in a wireless telephone network  60 . In this case, each wireless telephone  62   a ,  62   b ,  62   n  has an airlink modem  65   a ,  65   b ,  65   n  that allows the data packet to be accessed directly. Alternatively, using the airlink modem  65   a ,  65   b ,  65   n , the wireless telephones  62   a ,  62   b ,  62   n  can access processed data from the web server  26 , provided they have the appropriate software (e.g., web-browsing capabilities). In this case, the web server  26  formats the data in a manner suitable to wireless browsing (e.g. wireless access protocol). 
     The host computer system  12  typically works bi-directionally, i.e. it can receive emissions data from the data collector/routers  35   a ,  35   b ,  35   n  present on each vehicle  32   a ,  32   b ,  32   n , and send data to each vehicle using a similar methodology. 
     Data is typically sent from the host vehicle  32   a ,  32   b ,  32   n  to each data collector/router  35   a ,  35   b ,  35   n  at a predetermined time interval (e.g. a random or periodic time interval, such as every week or every 200 miles) that is programmed in either the data collector/router or the actual vehicle. Alternatively, data can be queried in response to a signal sent from the host computer system  12  to the data collector/routers  35   a ,  35   b ,  35   n  present on each vehicle  32   a ,  32   b ,  32   n.    
     FIG. 2 shows a typical data set  90  characterizing a vehicle&#39;s emissions sent from a vehicle&#39;s data collector/router to the host computer. The data set  90  includes a section  92  that describes each datum, a section  94  that lists the datum&#39;s numerical value, and a section  96  that lists the address of the datum&#39;s location in the vehicle&#39;s ECM (described in this case by a ‘PID’ code). The data in the set indicate properties relating to the vehicle&#39;s engine load, air-flow/intake behavior, and oxygen gas content of the vehicle&#39;s actual emission to the environment. The exact format, property description, and addresses used in the data set  90  may vary slightly from vehicle to vehicle; the data set show in FIG. 2 was measured from a Chevrolet Surburban. 
     Table 1, below, describes how data in the data set  90  relates to engine load, air-flow/intake behavior, and oxygen gas content: 
     
       
         
               
             
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 description of datum in Emissions Data Set 
               
             
          
           
               
                   
                 Description 
                 General Property 
               
               
                   
                   
               
               
                   
                 Fuel system status 
                 Engine load 
               
               
                   
                 Calculated load value 
                 Engine load 
               
               
                   
                 Engine coolant temp 
                 Engine load 
               
               
                   
                 Short term fuel trim bank 1 
                 Engine load 
               
               
                   
                 Fuel pressure gauge 
                 Engine load 
               
               
                   
                 Intake manifold pressure 
                 Air-flow/intake behavior 
               
               
                   
                 Engine speed 
                 Engine load 
               
               
                   
                 Vehicle speed 
                 Engine load 
               
               
                   
                 Ignition timing 
                 Engine load 
               
               
                   
                 Intake air temp 
                 Air-flow/intake behavior 
               
               
                   
                 Air flow rate 
                 Air-flow/intake behavior 
               
               
                   
                 Commanded sec. air status 
                 Air-flow/intake behavior 
               
               
                   
                 O2 sensor location 
                 oxygen gas content 
               
               
                   
                 O2 data bank 1 sensor 1 
                 oxygen gas content 
               
               
                   
                 O2 data bank 2 sensor 4 
                 oxygen gas content 
               
               
                   
                   
               
             
          
         
       
     
     FIG. 3 shows how, once collected and stored on the host computer system of FIG. 1, the data set  90  can be analyzed to determine the vehicle&#39;s emission performance. A microprocessor in the host computer system performs the analysis, which involves passing the numerical values and descriptions from the data set into a mathematical model  95 . The model processes them to predict emissions/pollutant concentration levels  100  for a particular vehicle. A particular model involves the following steps: 
     STEP 1—measuring a peak-to-peak variation in voltage from the vehicle&#39;s heated oxygen sensors distributed before (sensor  1 ) and after (sensor  2 ) the catalytic converter. 
     STEP 2—comparing the peak-to-peak variation in voltage in each sensor from step 1) to a ‘transfer function’ (i.e., a curve relating the sensor&#39;s voltage to an air-fuel ratio, or (air/fuel) actual /(air/fuel) stoichiometric ) to determine an effective range in air/fuel ratio (Δλ) for sensor  1  (Δλ 1 ) and sensor  2  (Δλ 2 ). 
     STEP 3—calculating an oxygen storage capacity (OSC) from the air-fuel ratio from step 2) using the equation: OSC=(1−Δλ 2 /Δλ 1 )*(Δλ 1 /C), where C=33,200/(LOAD*RPM) and LOAD and RPM are vehicle data queried from the vehicle&#39;s ECM through the OBD-II interface. 
     STEP 4—comparing the OSC value from 3) to a transfer function that relates this parameter to a hydrocarbon conversion efficiency transfer function to determine the relative deterioration of the vehicle&#39;s emissions performance. 
     Hydrocarbon conversion efficiency decreases with OSC. Thus, at low OSC values the hydrocarbon conversion efficiency is low, meaning that relatively high amounts of hydrocarbons are being released by the vehicle into the environment. 
     Other methods for calculating or predicting a vehicle&#39;s emissions can also be used in place of the above-mentioned algorithm. 
     Once determined, the predicted emissions/pollutant concentration levels  100  are compared to those mandated by a certifying organization  102  (e.g., the EPA) to determine the status of the vehicle. This last step, for example, is when a vehicle ‘passes’ or ‘fails’ a emissions check. 
     FIG. 4 shows a data collector/router  35  in electrical contact with a vehicle&#39;s OBD/ECU system  100  that sends a data packet containing the emissions data set over a wireless airlink. The data collector/router  35  and OBD/ECU system  100  connect through a conventional OBD-II connector  120  typically located under the vehicle&#39;s dashboard. The data collector/router  35  is contained in a small, portable housing that plugs directly into the connector  120  and can be easily installed and replaced. 
     The connector  120  has a serial,  16 -cavity layout, with specific electrical connections in each cavity supplying data and electrical power from the OBD/ECU system  100 . The connector electrically and mechanically matches an OBD-II interface  102  in the data collector/router  35 . Although the OBD-II connector  120  has a standard mechanical interface, data transmitted through it may have a format and pass through cavities that depend on the vehicle&#39;s make and model. For example, Ford and General Motors vehicles use an OBD data format called J1850; data in this format pass through cavities  2  and  10 . Chrysler and most European and Asian manufacturers use a data format called ISO 9141-2 and pass data through cavities  7  and  15 . In a third format, called J2284, data is passed through cavities  6  and  14 . 
     The connector  120  also passes battery power (cavity  16 ), automobile chassis ground (cavity  4 ), and signal ground (cavity  5 ) from the OBD/ECU system  100  through the OBD-II interface  102  to the data collector/router  35 . Using these connections, a power supply  105  receives the battery power, regulates it, and in turn drives a data processor  104  and wireless transmitter  106  within the data collector/router  35 . 
     Once received, data is passed to the data processor  104  (e.g., a microprocessor) that processes and formats it to form a data packet. As an example, a data packet specifically formatted for Bell South&#39;s wireless 900 MHz Mobitex MPAK system is described in Table 2, below. Actual data describing the host vehicle is contained in the 516-byte data area described in the table. 
     
       
         
               
             
               
               
             
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 description of Mobitex MPAK data packet 
               
             
          
           
               
                 Bytes 
                 General Description 
               
               
                   
               
               
                 3 
                 source MAN (unique 24-Bit modem number) 
               
               
                 3 
                 destination MAN (unique 24-Bit modem number) 
               
             
          
           
               
                 1 
                 when sending: 
                 Bit 0 = use mailbox 
               
               
                   
                   
                 Bit 1 = return positive acknowledgment 
               
               
                   
                   
                 Bit 2 = use address list 
               
               
                   
                   
                 Bits 3-7 = 0 
               
               
                   
                 when receiving: 
                 Bit 4 = may be ignored 
               
               
                   
                   
                 Bits 5-7 = traffic state 
               
               
                 1 
                 MPAK type 
               
               
                 0 or 22 
                 address list 
               
               
                 0 to 516 
                 data payload 
               
               
                   
               
             
          
         
       
     
     Once properly formatted as described in Table 2, the data packet is passed from the data processor  104  to the wireless transmitter  106 . The transmitter  106  transmits the data packet through a conventional wireless antenna  108  over an airlink  38  to a wireless communications system ( 15 ) shown in FIG.  1 . The data processor  104  formats the data packet according to the wireless communications system that transmits it. 
     The data area described in Table  2  contains data generated by the vehicle&#39;s OBD/ECU system  100 . As described above, this system  100  functions effectively as an on-board computer network that generates, transmits, and receives data. For simplicity, the system  100  in FIG. 4 contains two OBD-II systems  121   a ,  121   b  and two ECU systems  125   a ,  125   b ; it is analogous to more complex OBD-II and ECU systems employed in actual vehicles. The OBD-II systems  121   a ,  121   b  are microcontrollers that monitor the various vehicle-related properties described above (e.g., engine load and air-flow/intake behavior). The ECU systems  125   a ,  125   b  receive and send data to electromechanical actuators and sensors that measure, e.g., oxygen gas content. 
     The OBD-II systems  121   a ,  121   b  and ECU systems  125   a ,  125   b  are controlled by the vehicle&#39;s ECM/PCM  130 . In some cases, the ECM/PCM  130  receives data from these systems and routes it over a shared electronic OBD buss  133 . Alternatively, after receiving the data the ECM/PCM  130  converts it to “fail” or DTC codes that are then routed over the shared electronic buss  133 . In both cases, the OBD buss serially transmits data to the data collector/router  35  through the electrically connected OBD connector  120 . 
     FIG. 5 shows in more detail a vehicle&#39;s exhaust manifold  200  that is monitored using the above-mentioned algorithm. The exhaust manifold  200  features oxygen sensors  202   a - 202   d  that measure O 2  concentration for the emissions data set shown in FIG.  2 . These are similar to the oxygen sensors described in the above-mentioned method. The exhaust manifold  200  includes an upper  205   a  and lower  205   b  manifold, each of which includes, respectively, an oxygen sensor  202   a ,  202   b . The oxygen sensors  202   a ,  202   b  in the upper and lower manifolds  205   a ,  205   b  are located proximal to an engine block  210  that includes six cylinders  211 . The additional sensors  202   c ,  202   d  are located in a lower portion  215  of the exhaust manifold  200 . These sensors  202   c ,  202   d  are located on each side of a catalytic converter  220 . 
     Each of the oxygen sensors typically includes a ‘high’ and ‘low’ signal wire that connects to a comparator in the vehicle&#39;s PCM. The ‘low’ signal wire runs directly to the oxygen sensor to provide the comparator with a reference ‘low’. The ‘high’ signal wire connects directly to a portion of the sensor that is sensitive to the oxygen concentration. During operation of the vehicle, oxygen-containing exhaust flows by the oxygen sensors; in response the comparator generates a voltage that relates to the concentration of O 2  gas in the exhaust. The range in this voltage is similar to the range (Δλ) described in the above-mentioned method. 
     FIGS. 6A-6D show in more detail graphs of actual waveforms generated by the oxygen sensors ( 202   c ,  202   d ) disposed on each side of the catalytic converter  220  shown in FIG.  5 . The catalytic converter  220  contains one or more precious metals (e.g., palladium, platinum, rhodium) that oxidizes unburned hydrocarbons, carbon monoxide (CO), and oxides of nitrogen (No x ) that result from the combustion of gasoline. When the catalyst is working properly, the unburned hydrocarbon and carbon monoxide gases are oxidized to form water vapor (H 2 O) and carbon dioxide (CO 2 ). 
     As indicated in FIGS. 6A and 6B, a ‘good’ catalyst (e.g., one displaying 95% hydrocarbon conversion efficiency) will show a relatively flat time-dependent voltage output (FIG.  6 B), indicating that the oxygen gas flowing over the sensor has reached a relatively steady state. This is true even when the oxygen concentration measured before the catalytic converter is fluctuating with time, as indicated by FIG.  6 A. This indicates a high oxygen storage capability in the catalyst. Referring to the method described above, in this case Δλ 2  is much less than Δλ 1 , and the OSC and hydrocarbon conversion efficiency are both relatively high. 
     In contrast, under the same conditions, a ‘poor’ catalyst results in peaks and valleys in the output of the oxygen sensor after the catalytic converter, as indicated by FIG.  6 D. This indicates that the catalyst has a low oxygen storage capability, i.e. it has lost some of its ability to process the exhaust gasses properly. A catalyst that indicates a reduced efficiency based on the graph shown in FIG. 6D is likely to be inefficient in converting hydrocarbons as well as CO and NO x . According to the above-described method, in this case αλ 2  is similar in magnitude to Δλ 1 , and the OSC and hydrocarbon conversion efficiency are both relatively low. 
     Once the emissions data set is collected and analyzed as described above, the host computer remotely characterizes emissions from a large set of vehicles without requiring the vehicles to be brought into a service center. This allows, for example, ‘on-line emissions checks’ and related services to be performed. FIG. 7 shows a flow chart describing one method  150  of how data is analyzed in this manner and then made available to end-users through the Internet. A wide number of related data-analysis methods are possible; the one shown in FIG. 7 was chosen because of its simplicity. 
     In the data-analysis method  150 , the host computer system receives a data packet containing the emissions data set from the vehicle through the wireless communications network (step  152 ). The data set and data packets have formats shown, respectively, in Tables 1-2, above. Once received, the packet is analyzed and the host computer predicts emissions/pollutants concentrations (step  154  and step  100  in FIG. 3) using the above-described model. The host computer then compares the emissions/pollutant concentration levels to predetermined mandated levels to determine the emissions status of a particular vehicle (step  156  and step  102  in FIG.  3 ). At this point the results from steps  154  and  156  are distributed and stored in the data-memory module (e.g. a database) of the host computer system (step  158 ). Some data may be simply disregarded during this step. This portion (steps  152 ,  154 ,  156 , and  158 ) of the method  150  may be repeated at this point to generate additional data. 
     The emissions data can be posted directly on a Web page on the Web server (step  162 ) where it is accessible by the end-user through the Internet. For example, at this point the emissions data is posted to a Web server at an emissions-monitoring organization, e.g. the EPA. At this point the data may be stored (step  158 ) and then compared to emissions data collected at an earlier time (step  160 ) to determine the emissions ‘trends’ of a particular vehicle. A computer connected to the Web server then determines if the vehicle ‘passes’ or ‘fails’ an emissions ‘test’ that relies on predetermined criteria for acceptable emissions (step  163 ). The host computer system then notifies the user through electronic mail of the test results (step  164 ). The results of the test may also be stored in the host computer system (step  166 ) so that they can be accessed at a later time. 
     Other embodiments are within the scope of the invention. For example, depending on the make and model of the vehicle, the data packet can contain hundreds of additional datum that describe, e.g.: i) basic properties of the power train (e.g., emission levels, fuel-system status, engine temperature, speed and odometer readings, anti-lock brake status, RPMs, fuel and intake manifold pressure); and ii) manufacturer-specific information (e.g., status of the door locks, airbags, and entertainment center). In total, there are typically hundreds of datum that can be included in the data packet. Each of these can be analyzed in a manner similar to that described above to determine a variety of properties of the vehicle. 
     In addition, data packets routed through the wireless communications system  15  can be analyzed to determine the vehicle&#39;s approximate location. This can be done with relatively low accuracy (within a few miles) by simply recording the location of a specific base station in the hardware component  17  of the wireless communications system  15  that routes the data packet to the host computer system  12 . The accuracy of the vehicle&#39;s location is increased by recording the location of multiple base stations within range of the vehicle, and then analyzing these data using conventional triangulation algorithms. The data collector/router can also be modified to include hardware for global positioning (GPS). Using a satellite infrastructure, GPS hardware transmits real-time longitude and latitude values that can be analyzed to accurately determine a vehicle&#39;s location. 
     The components used in the data collector/router (particularly the wireless transmitter) may also be optimized for different types of wireless communications systems. These systems include wireless telephone and paging systems, Bluetooth®, and similar systems. Similarly, the format of the data packet may also be adjusted for transmission over different types of networks. In general, any components in the data collector/router, and any format of the data packet, can be used to accomplish the general method of the invention. 
     Likewise, a wide range of additional mathematical algorithms can be used to analyze data once it is extracted from the data packets. These algorithms range from the relatively simple (e.g., simple comparative algorithms) to the complex (e.g., predictive engine diagnoses using ‘data mining’ techniques). Data analysis may be used to characterize an individual vehicle as described above, or a collection of vehicles. Algorithms used to characterize a collection of vehicles can be used, for example, for remote vehicle or parts surveys, to characterize emission performance in specific geographic locations, or to characterize traffic. 
     Other embodiments of the invention include algorithms for analyzing data to characterize vehicle accidents and driving patterns for insurance purposes; algorithms for determining driving patterns for use-based leasing; algorithms for analyzing data for insurance purposes; and algorithms for recording vehicle use and driving patterns for tax purposes. In general, any algorithm that processes data collected with the above-described method is within the scope of the invention. 
     Similarly, the temporal or mileage frequency at which data is collected can be adjusted to diagnose specific types of problems. For example, characterization of certain types of vehicle performance indicators, such as emissions, may need to be monitored relatively frequently. Other properties, such as mileage and fluid levels, may only need to be monitored every few days, or in some cases just a few times each year. 
     Once the data are analyzed, the Web page used to display the data can take many different forms. Different Web pages may be designed and accessed depending on the end-user. For example, individual users may have access to Web pages for their particular vehicle. Conversely, vehicle service providers (e.g. providers that change oil or certify a vehicle&#39;s emissions) may have access to Web pages that contain data (e.g., mileage and emissions data) from a wide range of vehicles. These data, for example, can be sorted and analyzed depending on vehicle make, model, and geographic location. Web pages may also be formatted using standard wireless access protocols (WAP) so that they can be accessed using wireless devices such as cellular telephones, personal digital assistants (PDAs), and related devices. 
     In other embodiments, data from the data collector/router in the vehicle can be analyzed and used for: remote billing/payment of tolls; remote emissions checks; remote payment of parking/valet services; remote control of the vehicle (e.g., in response to theft or traffic/registration violations); and general survey information. 
     Still other embodiments are within the scope of the following claims.