Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
The present disclosure relates to a method for indicating remaining distance to empty fuel of a vehicle and more specifically to indicating said remaining distance to empty fuel to the driver on a vehicle dashboard taking into consideration the diesel particulate filter regeneration and DeSOx regeneration method.

Background of the invention
[0002] Thermal regeneration of Diesel Particulate Filters (hereafter, DPF) involves the oxidation of solid particulates to gaseous products, preferably to CO2. It is known that the exhaust gas after-treatment systems of a diesel engine can be provided, among other devices, with a Lean NO Trap (hereafter, LNT). Depending on the DPF system design and on the engine operating conditions (exhaust gas temperature), the oxidation of carbon in diesel soot can occur via reactions with oxygen or nitrogen dioxide.
[0003] Oxygen is present in diesel exhaust at sufficient concentrations at nearly all operating conditions. However, relatively high temperatures are necessary to achieve appreciable regeneration rates with O2. Oxygen based regeneration is mostly seen in active DPF systems.
[0004] Nitrogen-dioxide based regeneration can be conducted at lower temperatures than oxygen regeneration. However, the NO2 concentrations must be increased, which is typically realized via catalytic oxidation of NO (i.e., by increasing the NO2:NO ratio in NOx). Oxidation of soot by NO2 is the dominant mechanism of passive DPF regeneration.
[0005] Unfortunately, due to the presence of sulphur into the fuel, the LNT is also exposed to the sulphur poisoning, which heavily reduces the NOx storage capacity of the catalyst. In order to re-enable the capability of the after-treatment system, a desulphation (also called DeSOx regeneration or simply DeSOx) is needed. The DeSOx consists in a fast alternation of lean and rich atmosphere at high temperature during engine working condition.

[0005] Filters are designed to burn off the accumulated particulate either passively through the use of a catalyst or by active means such as a fuel burner which heats the filter to soot combustion temperatures. This is accomplished by engine programming to run (when the filter is full) in a manner that elevates exhaust temperature, in conjunction with an extra fuel injector in the exhaust stream that injects fuel to react with a catalyst element to burn off accumulated soot in the DPF filter, or through other methods. In the current logic only normal mode (fuel injections - Torque generating fuel quantity) are considered for predicting the remaining distance to empty the fuel tank.

[0005] The distance to empty fuel tank (complete consumption of fuel) is determined using the instantaneous fuel consumption and fuel quantity in the fuel tank and indicated in dashboard.
During exhaust gas treatment mode additional post injections (non-torque generating quantity) are injected which is not considered in advance for the calculation of distance to empty fuel tank. Which leads to wrong indication to driver and higher distance is intimated in the dashboard,
e.g when the actual fuel is less in the tank and the distance to empty is more.

[0006] In order to achieve the above purpose, the present invention is a method for indicating the distance to empty fuel of a vehicle to the driver. The filter regeneration system includes an ECU (105) that controls filter regeneration processing for the DPF (120). The ECU (105) calculates a fuel consumption learnt values during regeneration and DeSOx at a current time point on the basis of a physical model indicative of an actual remaining fuel in fuel tank, calculates a remaining fuel amount at the current time point on the basis of a time model by subtracting the calculated fuel consumption values during regeneration and DeSOx from the net fuel in the fuel tank and notifies a driver of the estimated remaining distance to empty fuel of a vehicle on the dashboard (115).

Brief description of the accompanying drawings
[0006] An embodiment of the disclosure is described with reference to the following accompanying drawings,
[0007] Figure 1 illustrates an overall configuration diagram of a filter regeneration system.

[0008] Figure 2 illustrates a flowchart of estimated remaining fuel in fuel tank calculation processing.

Detailed description of the drawings
[0009] In order to achieve the above purpose, the present invention is a method for indicating the remaining distance to empty fuel of a vehicle to the driver. The filter regeneration system includes an ECU (105) that controls filter regeneration processing for the DPF (120). The ECU (105) calculates a fuel consumption learnt values during regeneration and DeSOx at a current time point on the basis of a physical model indicative of an actual remaining fuel in fuel tank, calculates a remaining fuel amount at the current time point on the basis of a time model by subtracting the calculated fuel consumption values during regeneration and DeSOx from the net fuel in the fuel tank and notifies a driver of the estimated remaining distance to empty fuel of a vehicle on the dashboard (115).

[0010] Fig. 1 is an overall configuration diagram of a filter regeneration system (100). The filter regeneration system (100) includes: an engine (125) that serves as a power source of a vehicle; an ECU (105) that controls the engine (125); an aftertreatment device that treats exhaust gas from the engine (125); and an in-vehicle instrument (110) that acquires information of the vehicle from the ECU (105) and displays the information of the vehicle for a driver on the dashboard (115).

[0011] Upon the DPF regeneration, the ECU (100) calculates a fuel consumption learnt values during regeneration and DeSOx in a specified cycle from the like of the exhaust gas and subtracts the integrated fuel consumed from actual remaining fuel in fuel tank of the vehicle. In this way, the remaining fuel in fuel tank is calculated and further distance to empty fuel of a vehicle can be derived.

[0012] The ECU (105) executes processing as illustrated in Fig 2.

[0013] First, the ECU (105) monitors the accumulated soot and sulphur values in the diesel particulate filter and Lean NOx trap respectively. The ECU (105) then triggers regeneration of said diesel particulate filter and DeSOx when said accumulated soot and sulphur values reach a threshold value. Said threshold value being already fed into the ECU (105). Next, the fuel amount used in said regeneration method is subtracted from remaining fuel in said fuel tank. Finally, the display instruction is used to display the remaining distance to empty fuel of a vehicle on the dashboard (115).

[0014] According to the present invention, an efficient travel plan can be created for the driver by notifying the driver of the estimated remaining fuel in fuel tank and further the distance to empty fuel. In turn, this alerts the driver to refuel based on their travel itinerary and makes it convenient for them.

[0015] It must be understood that the embodiments explained in the above detailed description are only illustrative and do not limit the scope of this invention. Any modification to the method to indicate remaining distance to empty fuel of a vehicle are envisaged and form a part of this invention. The scope of this invention is limited only by the claims.
 
, Claims:We Claim:
1. A method for indicating remaining distance to empty fuel of a vehicle comprising at least a diesel particulate filter (120) and a control unit (105), said method comprising:
-monitoring the accumulated soot and sulphur values in said diesel particulate filter and Lean NOx trap respectively by said control unit (105),
-triggering regeneration of said diesel particulate filter and DeSOx when said accumulated soot and sulphur values reach a threshold value,
-subtracting fuel amount used in said regeneration method from remaining fuel in said fuel tank and indicating said remaining distance to empty fuel of a vehicle dashboard (115).

2. The method for indicating remaining distance to empty fuel of a vehicle as claimed in claim 1, where threshold value of accumulated soot and sulphur is preset in said control unit (105).

3. The method for indicating remaining distance to empty fuel of a vehicle as claimed in claim 1, wherein regeneration of said diesel particulate filter, DeSOx, Rapid Heatup mode (RHU) are done using fuel injections for increasing the exhaust temperature.