Patent Application
20140200793
1. Field
The present invention relates to a method and a system for determining and displaying a fuel-equivalent distance-per-energy consumption rate and more particularly, to a method and a system for determining and displaying a number of miles travelled by the vehicle per a gallon of total fuel and non-fuel energy consumed over a time period or a number of kilometers travelled by the vehicle per a liter of total fuel and non-fuel energy consumed over a time period.
2. Description of the Related Art
With global energy prices rapidly increasing, a user of a vehicle having a rechargeable battery is increasingly interested in evaluating what distance the vehicle can travel for an amount of energy consumed. Because conventional vehicles have relied solely on a fuel energy source, vehicle users have been accustomed to evaluating the number of miles that the vehicle can travel per one gallon of fuel (MPG) or the number of kilometers that the vehicle can travel per one liter of fuel (Km/l).
For hybrid and plug-in hybrid vehicles, a drawback of presenting MPG or Km/l information merely based on fuel consumption is that the vehicle user cannot make an accurate assessment of the distance the vehicle can travel per an amount of energy consumed since non-fuel energy consumption (e.g., electrical energy consumption) is not taken into account. For example, the battery may be discharging, thereby depleting energy, and yet the electrical energy consumption would not be taken into account in the fuel MPG or Km/l information displayed to a user of the vehicle.
In order to enable the vehicle users to evaluate the energy efficiency of the vehicle, manufacturers have sought novel ways to convey energy efficiency information to the vehicle users. A drawback of the energy efficiency indicators has been that an average vehicle user without engineering expertise may not find the energy efficiency information tangible and easy to understand.
Thus, there is a need for a method and a system directed to determining and displaying easily understandable data regarding what distance a vehicle can travel for an amount of fuel or fuel-equivalent non-fuel energy consumed. Furthermore, there is a need for a method and a system for determining and displaying a fuel-equivalent MPG or Km/l rate based on gallons or liters of total fuel and fuel-equivalent non-fuel energy consumed. There is also a need for a method and a system directed to displaying a fuel-equivalent energy cost corresponding to a cost amount for travelling a kilometer or a mile of the distance travelled over a time period during which the total fuel and fuel-equivalent non-fuel energy is consumed. There is yet another need for a method and a system of determining a distance-per-energy consumption rate for tuning an operation of the engine and a charging/discharging operation of the battery in order to reach an operating point that maximizes total energy efficiency.
The present invention relates to a method and a system for determining and displaying a fuel-equivalent distance-per-energy consumption rate and more particularly to a method and a system for determining and displaying a number of miles travelled by the vehicle per one gallon of total fuel and fuel-equivalent non-fuel energy consumed or a number of kilometers travelled by the vehicle per one liter of total fuel and fuel-equivalent non-fuel energy consumed. In one embodiment, the present invention may be, for example, a computer-based method for determining and displaying a fuel-equivalent distance-per-energy consumption rate of a vehicle, the method including: determining, using a fuel controller coupled to an engine or a fuel cell, a fuel consumption rate or amount; determining, using a battery management and charging unit (BMCU) coupled to a battery, an electrical energy consumption rate or amount; determining, using an electronic control unit coupled to a speed sensor, a distance travelled by the vehicle during a time period; determining, using the electronic control unit, the fuel-equivalent distance-per-energy consumption rate based on the fuel and electrical energy consumption rates or amounts and based on the determined distance travelled during the time period; and displaying, using a display coupled to the electronic control unit, an indicator based on the fuel-equivalent distance-per-energy consumption rate for indicating an amount of distance travelled by the vehicle for an amount of fuel-equivalent energy consumed.
In another embodiment, the present invention may be computer-based method for determining and displaying a fuel-equivalent distance-per-energy rate of a vehicle, the method including: determining, using a fuel controller coupled to an engine or a fuel cell, a first energy consumption sum amount corresponding to an amount of fuel energy consumed by an engine or a fuel cell during a time period; determining, using an electronic control unit, a second energy consumption sum amount corresponding to an amount of energy consumed using a non-fuel energy source during the time period; determining, using the electronic control unit and a speed sensor coupled to the electronic control unit, a distance travelled by the vehicle during the time period; determining, using the electronic control unit, a fuel-equivalent total energy consumption sum amount based on the first and the second consumption sum amounts; determining, using the electronic control unit, the fuel-equivalent distance-per-energy consumption rate based on the determined fuel-equivalent total energy consumption sum amount and the determined distance travelled during the time period, such that the fuel-equivalent distance-per-energy consumption rate corresponds to a number of or a fraction of miles travelled per a gallon of the fuel-equivalent total energy consumption sum amount or corresponds to a number of or a fraction of kilometers travelled per a liter of the fuel-equivalent total energy consumption sum amount; and displaying, using a display coupled to the electronic control unit, an indicator based on the determined fuel-equivalent distance-per-energy consumption rate.
In yet another embodiment, the present invention may be a vehicle including: an engine; a fuel controller coupled to the engine and configured to determine a fuel consumption rate or amount of the engine; a battery management and charging unit (BMCU) coupled to a battery and configured to control and monitor charging and discharging of the battery and further configured to determine an electrical energy consumption rate or amount of the battery; an energy generation unit including a solar panel, a ram induction generator, a regenerative braking unit, a heat exchange unit or combinations thereof, the energy generation unit having an energy generation rate or amount; an electronic control unit coupled to the engine, the energy generation unit, the fuel controller and the BMCU and configured to: determine, using a speed sensor, a distance travelled by the vehicle during a time period, determine a fuel-equivalent distance-per-energy consumption rate based on the determined fuel consumption rate or amount, electrical energy consumption rate or amount, energy generation rate or amount and the distance travelled during the time period; and the vehicle further including a display coupled to the electronic control unit and configured to display an indicator based on the determined fuel-equivalent distance-per-energy consumption rate, the indicator corresponding to an amount of distance travelled by the vehicle for an amount of fuel-equivalent energy consumed.
Other systems, methods, features, and advantages of the present invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims. Component parts shown in the drawings are not necessarily to scale, and may be exaggerated to better illustrate the important features of the present invention. In the drawings, like reference numerals designate like parts throughout the different views, wherein:
Referring to
The vehicle 100 operates by utilizing a fuel source and a non-fuel source of energy. The vehicle 100 may be an alternative fuel vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric vehicle or a solar powered vehicle or any other vehicle utilizing a non-fuel source of energy without limiting the scope of the present invention. The vehicle 100 may determine and display a fuel-equivalent distance-per-energy consumption rate by converting energy consumption in all forms of energy into a fuel-equivalent energy consumption rate or amount.
The electronic control unit 102 may be in continuous or periodic communication with the display 104, the engine 106, the engine fuel controller 108, the BMS 114, the charger 112 and other units of the vehicle 100 using transmission of electronic signals through a Control Area Network (CAN) bus. In other embodiments, the control and communication may be over various other types of serial communication links, direct wirings, digital communication buses, wireless communications or other communication links.
The engine fuel controller 108 controls and monitors injection of fuel into the engine 106 for an internal combustion operation. To determine the fuel consumption rate or amount, the electronic control unit 102 may be in periodic communication with the engine fuel controller 108. The fuel controller 108 may be a fuel injector system. The amount of fuel supplied to the engine 106 may be determined based in part on the pulse width of the fuel injector. The engine fuel controller 108 and/or the electronic control unit 102 may determine a fuel consumption rate using a mass airflow sensor, an oxygen sensor, a throttle position sensor monitoring the throttle valve position, a coolant temperature sensor, an air pressure sensor, engine speed sensor, and/or other input sensors generating signals allowing the electronic control unit 102 to determine the fuel consumption rate or amount. The electronic control unit 102 may use a look-up table, an algorithm or data stored in a memory (not shown) to determine the fuel consumption amount or value. The memory may be integral to or connected to the electronic control unit 102. The electronic control unit 102 and the memory may reside in an Application Specific Integrated Circuit (ASIC). The ASIC may reside in a wireless modem. In the alternative, the electronic control unit 102 and the memory may reside as discrete components in the wireless modem.
Various types of fuel may be used by the vehicle 100 including but not limited to gasoline, diesel, ethanol, biodiesel, natural gas, propane, hydrogen or combinations thereof. The vehicle 100 may also include a fuel cell in lieu of or in addition to the engine 106 which may charge the battery 118 and/or a capacitor by converting a fuel through a chemical reaction with an oxidizing agent. A fuel consumption sum amount may be calculated and communicated with the electronic control unit 102 in order to determine the fuel consumption rate.
To determine the fuel-equivalent distance-per-energy consumption rate, the electronic control unit 102 may determine the distance travelled during a time period. In one embodiment, the electronic control unit 102 may determine the vehicle speed during the time period using the vehicle speed sensor 120. The electronic control unit 102 may then integrate the vehicle speed over the time period to determine the distance travelled by the vehicle 100 during the time period.
In one embodiment, the battery 118 provides electrical energy for the operation of the vehicle 100. The battery 118 may be any rechargeable battery that is capable of being utilized in the vehicle 100 and may include a plurality of battery cells. The battery 118 may be charged, using the motor/generator, by converting fuel energy into electrical energy stored by the vehicle 100. The battery 118, as in for example, an all-electric or a plug-in hybrid vehicle, may be charged using an external charger coupled to the charger 112 or the battery 118.
The electrical energy consumption can be determined by measuring the electrical energy in and out of the battery 118. A change in the level of a state of charge (SOC) of the battery 118 may indicate an electrical consumption rate or amount. The BMS 114 may measure, using sensors, parameters that are used to determine the SOC of the battery 118. The sensors may measure a voltage, a current, a temperature, charge acceptance, an internal resistance, self-discharges, magnetic properties, a state of health and/or other states or parameters of the battery 118. In one embodiment, the electronic control unit 102 may determine an SOC percentage or ratio of the battery 118 based on an energy value stored in the battery 118 or the vehicle 100 relative to the current charging capacity of the battery 118. In another embodiment, the BMS 114 can transmit control signals to relays for selectively activating a connection of the battery 118 to various loads positioned inside the vehicle 100. The loads can be, for example, various units or devices of the vehicle 100 having programmable memory items. The electronic control unit 102 may or may not manipulate the SOC or the display SOC. In one embodiment, the electronic control unit 102 may have access to the SOC of the vehicle 100 or the battery 118 for controlling the display 104 and operations of others units of the vehicle 100.
In another embodiment, the SOC may be determined based on the stored energy value relative to a reference capacity for the battery 118 stored in the memory. In yet another embodiment, the SOC may be measured as a percentage or a ratio relative to another predetermined value associated with the battery 118. The SOC may be determined in amp hours (Ah) or kilowatt hours (kW-h) of energy. In another embodiment, the electronic control unit 102 determines a display SOC based on the measured SOC of the battery 118 such that the display SOC may differ from the measured SOC for a range of SOC values. For example, the display SOC may correspond to a percentage greater than the measured SOC when the measured SOC is higher than a threshold. In an embodiment, the electronic control unit 102 may utilize the display SOC to determine the fuel-equivalent consumption rate or amount. Other systems or methods known in the art for determining an SOC percentage, value or number may be utilized in the vehicle 100 without limiting the scope of the present invention.
The electronic control unit 102 may determine the fuel-equivalent consumption rate of the electrical energy consumption based on the variation in the SOC of the battery 118. For example, a 33.7 kW-h change in the SOC may correspond to energy stored in approximately one gallon of gasoline. The consumed electrical energy may be converted into a fuel-equivalent amount of energy and added with the fuel consumption sum amount to obtain a fuel-equivalent total energy consumption sum amount as described in details below. Once the total number of gallons or liters of a fuel-equivalent total energy consumption sum amount is determined, the electronic control unit 102 may divide the travelled distance (miles or kilometers) by the amount of energy of the fuel-equivalent total energy consumption sum amount (gallons or liters) to determine a fuel-equivalent distance-per-energy consumption rate, e.g., in miles per gallon equivalent (MPG-e) or kilometers per liter equivalent (Km/l-e).
In one embodiment, the battery 118 may be coupled to an external charger before the departure time of the vehicle 100. In one embodiment, the BMCU 116 is coupled to an external power source. The external power source includes an A.C. power source which is coupled to an external charger positioned outside the vehicle 100. The external charger may be any of the various types of electric vehicle charging stations, wall-mountable electric charging solutions or electric vehicle supply equipment utilized in residential or commercial settings. The external charger is coupled to the charger 112 which may be positioned inside the vehicle 100 in one embodiment of the present invention as shown in
The stored electrical energy may be obtained through charging using an external power source, fuel consumption energy from the engine 106, energy generated by the energy generation unit 110 (e.g., via regenerative braking) or other means. In an embodiment, the battery 118 may also be a capacitor which may be charged by an energy generation unit 110. A supplemental motor/generator may be configured to apply a torque or a mechanical force to operate the vehicle 100. The energy generation unit 110 may include a solar panel, a ram induction generator, a regenerative braking unit, a heat exchange unit or combinations thereof. The supplemental motor/generator may supplement the torque applied by the engine 106. The vehicle 100 may also include a catalytic converter connected to the engine 106 to generate heat used by the energy generation unit 110 to charge the battery 118. The supplemental motor/generator may then be powered by discharging the battery 118 or the capacitor. In one embodiment, the electronic control unit 102 determines the fuel-equivalent non-fuel energy consumption sum amount based on the energy generated by the energy generation unit 110 and further based on the energy conversion efficiency of the energy generation operation as discussed in details with respect to
In one embodiment, the electronic control unit 102 periodically (e.g., every 500 milliseconds) determines a fuel-equivalent distance-per-energy consumption rate and periodically communicates the determined rate to the display 104. The electronic control unit 102 or a separate display controller may direct the display 104 to display an image based on the determined fuel-equivalent distance-per-energy consumption rate. The electronic control unit 102 may also direct the display 104 to illuminate or de-illuminate a number of lights or light-emitting diodes based on the determined fuel-equivalent distance-per-energy consumption rate and a data sequence stored as an algorithm or a look-up table in a memory.
One benefit of the invention is to show the user a more accurate indication of energy consumption by displaying and determining MPG-e or Km/l-e in real time, thereby allowing the vehicle users to assess the overall energy efficiency of the vehicle 100 or adjust their driving habits to achieve improved overall energy efficiency based on an easily understandable yet accurate metric. An MPG indication based solely on fuel consumption would not be an accurate indication of energy consumption because electrical energy consumption would not be taken into account. A distance-per-energy consumption computed in a conventional vehicle would show an artificially high MPG or Km/l. Another benefit of the invention is that the electronic control unit 102 or another controller/processor may improve an engine operation, a charging/discharging operation, power control, an HVAC operation, tuning or other operations of the units of the vehicle 100 based on the continuously updated MPG-e or Km/l-e. Such a feedback system enhances an overall energy efficiency of the vehicle 100.
Referring to
The control logic block diagram 200 is further configured to determine the electrical energy consumption rate or amount 204 by, for example, monitoring the SOC of the battery 118 as discussed above. An initial fuel-equivalent electrical energy consumption sum amount may be determined by integrating or adding the electrical energy consumption rate or amount 204 over the time period. The initial fuel-equivalent electrical energy consumption sum amount may be converted to the fuel-equivalent electrical energy consumption sum amount 208 expressed, for example, in fuel-equivalent units (gallons or liters). Since both fuel consumption sum amount 206 and the fuel-equivalent electrical energy consumption sum amount 208 may be expressed in fuel-equivalent units, the electronic control unit 102 may add the two values to obtain a fuel-equivalent total energy consumption sum amount 210 expressed in either gallons or liters. The MPG-e or Km/l-e may be computed, using the electronic control unit 102, based on the determined fuel-equivalent total energy consumption sum amount 210 and the distance travelled by the vehicle 100 during the time period.
Referring to
In one embodiment, the vehicle 100 may be a hybrid vehicle operating alternatively on electricity or fuel. As the SOC of the battery 118 decreases in segment 312, no fuel is being injected into the engine 106. The fuel consumption sum amount 330 remains unchanged as shown in segment 332 because only electrical energy is being depleted. A traditional real-time MPG calculation would report an artificially high MPG since no fuel is being consumed. However, in this embodiment, the electronic control unit 102 recognizes that the fuel-equivalent total energy consumption sum amount 350 is rising as shown in segment 352. A similar pattern applies to the variations in the SOC of the battery 118 in segments 316 and 322, respective fuel consumption sum amounts in segments 336 and 342 and respective fuel-equivalent total energy consumption sum amounts in segments 356 and 362. In segment 314, the SOC of the battery 118 is not being depleted and the vehicle 100 is operating solely on fuel energy from fuel injection. The fuel consumption sum amount 330 in segment 334 and the fuel-equivalent total energy consumption sum amount 350 in segment 354 increase by the same degree or slope.
In order to compute the fuel-equivalent total energy consumption sum amount 350, when the SOC of the battery 118 is increasing, the electronic control unit 102 may distinguish between the sources that provide the stored electrical energy, given that the fuel-equivalent total energy consumption sum amount 350 may depend upon the source of the provided electrical energy and how the vehicle 100 converts a form of energy into the provided electrical energy stored in the battery 118. Referring to
In an embodiment of the present invention, if fuel is being consumed leading to a rise in the fuel consumption sum amount 330 and if simultaneously, the SOC of the battery 118 increases via recapturing energy generated from a regenerative braking mechanism of the energy generation unit 110, the electronic control unit 102 may not decrease the rate at which the fuel-equivalent total energy consumption sum amount 350 increases (unlike segments 358 and 360 discussed above). The underlying rationale for such an embodiment is that the electrical energy provided for charging the battery 118 is not directly obtained from consumption of fuel energy. As a result, the electronic control unit 102 evaluates the overall energy efficiency, fuel consumption sum amount 330, fuel-equivalent total energy consumption sum amount 350 and fuel-equivalent distance-per-energy consumption rate based on the source of the increase in the SOC of the battery 118.
Similarly, in order to compute the fuel-equivalent total energy consumption sum amount 350, when the SOC of the battery 118 is decreasing, the electronic control unit 102 may distinguish between various discharging operations. For example, if the battery 118 is discharged to power auxiliary loads such as headlights, the HVAC unit and/or other units of the vehicle 100 while the vehicle 100 is in a stationary state, the electronic control unit 102 would recognize that the electrical energy consumed by the auxiliary loads is unrelated to the energy efficiency for a driving operation of the vehicle 100. Therefore, in a stationary state, the electronic control unit 102 may not significantly alter the fuel-equivalent total energy consumption sum amount 350 on the basis of the energy consumed by the auxiliary loads.
Referring to
In step 406, the integration may result in a number or value expressed in an initial unit of energy (e.g., kW-h) and then converted into equivalent gallons or liters of equivalent fuel (e.g., gasoline). The fuel-equivalent total energy consumption sum amount may be determined in step 424 by, for example, adding the fuel consumption sum amount from step 412 and non-fuel consumption sum amount from step 422. Simultaneously in real-time during the operation of the vehicle 100, the electronic control unit 102 may determine the vehicle speed during the time period in step 426 and integrate the vehicle speed over the time period in step 428 to determine the distance (in Km or miles) travelled over the time period in step 430 as discussed above. In step 432, the electronic control unit 102 divides the distance from step 430 over the fuel-equivalent total energy consumption sum amount from step 424. The determined fuel-equivalent distance-per-energy rate may be expressed in either MPG-e or Km/l-e.
Referring to
Referring to
Referring to
For a conventional hybrid vehicle, an accurate MPG-e or Km/1-e indication may require determination of an energy loss number or factor given that most or all of the energy in the battery 118 has been obtained from the engine 106. Although in a standard condition, 33.7 kWh of non-fuel energy may equate to the energy stored in a gallon of gasoline, only a percentage of the energy may be available for later use. As such, the electronic control unit 102 may consider the energy lost based on engine efficiency, the energy lost when fuel energy is being converted into electrical energy stored in the battery 118 and energy lost during a charging operation of the battery 118. For example, as discussed above with respect to
As shown in
The logical modules and steps for the vehicle 100 described in connection with the examples disclosed above may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. Exemplary embodiments of the invention have been disclosed in an illustrative style. Accordingly, the terminology employed throughout should be read in a non-limiting manner. Although minor modifications to the teachings herein will occur to those well versed in the art, it shall be understood that what is intended to be circumscribed within the scope of the patent warranted hereon are all such embodiments that reasonably fall within the scope of the advancement to the art hereby contributed, and that that scope shall not be restricted, except in light of the appended claims and their equivalents.
