# US 10,371,069 B2 · Control system for a flexible fuel internal combustion engine

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- Number: US 10,371,069 B2
- Document ID: US10371069B2
- Status: Granted
- Kind: B2
- Application number: 15/038,196
- Filed: 2014-11-06
- Published: 2016-10-06
- Granted: 2019-08-06
- Earliest claimed: 2013-11-22
- Assignees: Westport Power Inc.
- Applicants: Westport Power Inc.
- Inventors: Raymond Bzymek; Brian Chambers; Mark E. Dunn
- Web page: https://patentgrep.com/patent/US10371069B2

## CPC

- F02D 41/0025: {Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures}
- F02D 19/061: {by controlling fuel injectors}
- F02D 19/0644: {the gaseous fuel being hydrogen, ammonia or carbon monoxide}
- F02D 19/0692: {Arrangement of multiple injectors per combustion chamber}
- F02D 19/0694: {operating with a plurality of fuels}
- F02D 19/08: simultaneously using pluralities of fuels (F02D19/12 takes precedence)
- F02D 19/081: {Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other}
- F02D 41/26: using computer, e.g. microprocessor
- F02D 41/266: {the computer being backed-up or assisted by another circuit, e.g. analogue}
- F02D 41/3094: {the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder}
- F02D 41/40: with means for controlling injection timing or duration
- F02D 19/0647: {the gaseous fuel being liquefied petroleum gas [LPG], liquefied natural gas [LNG], compressed natural gas [CNG] or dimethyl ether [DME]}
- F02D 19/0689: {for in-cylinder direct injection}
- F02D 41/0027: {the fuel being gaseous (non-electrical control F02D19/02)}
- F02D 2400/11: After-sales modification devices designed to be used to modify an engine afterwards
- Y02T 10/30: Use of alternative fuels, e.g. biofuels
- Y02T 10/40: Engine management systems
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

In previous control systems for engines that fuelled with a conventional fuel and an alternative fuel, a conventional fuel controller controlled fuelling for both fuels. This required extensive modifications to both the conventional fuel controller and an alternative fuel controller. A control system for an engine comprises a first control unit programmed to generate a first pulse width to actuate a first fuel injector to introduce a first fuel; a second control unit programmed to generate a second pulse width to actuate a second fuel injector to introduce a second fuel; and a communication line between the first and second control units. The first control unit determines a total fuel energy amount to be introduced by the first and second fuel injectors. The second control unit determines a first fraction of the total fuel energy amount to be from the first fuel and a second fraction of the total fuel energy amount to be from the second fuel.

## Claims

### Claim 1

A control system for an engine comprising:
a first fuel injector;
a first connection connected with the first fuel injector;
a first control unit connected with the first connection and programmed to generate a first pulse width, which in operation is delivered to the first fuel injector over the first connection to actuate the first fuel injector to introduce a first fuel;
a second fuel injector;
a second connection connected with the second fuel injector;
a second control unit connected with the second connection and programmed to generate a second pulse width, which in operation is delivered to the second fuel injector over the second connection to actuate the second fuel injector to introduce a second fuel; and
a communication bus allowing the first and second control units to exchange information;
wherein the first control unit is further programmed to determine a total fuel energy amount to be introduced by the first and second fuel injectors and to transfer the total fuel energy amount to the second control unit over the communication bus,
wherein the second control unit is further programmed to determine a first fraction of the total fuel energy amount to be from the first fuel and a second fraction of the total fuel energy amount to be from the second fuel.

### Claim 2 (depends on 1)

The control system of claim 1, wherein the first control unit is further programmed to determine the first pulse width as a function of the first fraction of the total fuel energy amount, and the second control unit is further programmed to determine the second pulse width as a function of the second fraction of the total fuel energy amount.

### Claim 3 (depends on 1)

The control system of claim 1, wherein at least one of:
the first fuel is a liquid fuel and the second fuel is a gaseous fuel;
the first fuel is one of gasoline, diesel, ethanol and mixtures of these fuels; and
the second fuel is at least one of butane, ethane, hydrogen, methane, propane and natural gas and mixtures of these fuels.

### Claim 4 (depends on 1)

The control system of claim 1, wherein the communication bus is a dedicated link between the first control unit and the second control unit.

### Claim 5

A control system for an engine comprising:
a first fuel injector;
a first connection connected with the first fuel injector;
a first control unit connected with the first connection and programmed to generate a first pulse width, which in operation is delivered to the first fuel injector over the first connection to actuate the first fuel injector to introduce a first fuel;
a second fuel injector;
a second connection connected with the second fuel injector;
a second control unit connected with the second connection and programmed to generate a second pulse width, which in operation is delivered to the second fuel injector over the second connection to actuate the second fuel injector to introduce a second fuel; and
a communication bus allowing the first and second control units to exchange information;
wherein the first control unit is further programmed to determine a total fuel energy amount to be introduced by the first and second fuel injectors and to transfer the total fuel energy amount to the second control unit over the communication bus,
wherein the second control unit is further programmed to determine a first fraction of the total fuel energy amount to be from the first fuel and a second fraction of the total fuel energy amount to be from the second fuel, and
wherein the first control unit transfers the total fuel energy amount to the second control unit over the communication bus, and the total energy amount is one of a first quantity of the first fuel and a second quantity of the second fuel.

### Claim 6 (depends on 5)

The control system of claim 5, wherein the second control unit transfers at least one of the first fraction and the second fraction to the first control unit over the communication bus.

### Claim 7 (depends on 6)

The control system of claim 6, wherein the first control unit is further programmed to calculate a third quantity of the first fuel to be injected by the first fuel injector.

### Claim 8 (depends on 7)

The control system of claim 7, wherein the first control unit is further programmed to calculate a fourth quantity of the second fuel to be injected by the second fuel injector, and the first control unit transfers the fourth quantity to the second control unit over the communication bus.

### Claim 9 (depends on 7)

The control system of claim 7, wherein the second control unit is further programmed to calculate a fourth quantity of the second fuel to be injected by the second fuel injector.

### Claim 10 (depends on 5)

The control system of claim 5, wherein the second control unit is further programmed to calculate a third quantity of the first fuel to be injected by the first fuel injector and a fourth quantity of the second fuel to be injected by the second fuel injector, and the second control unit transfers the third quantity to the first control unit over the communication bus.

### Claim 11 (depends on 1)

The control system of claim 1, wherein the second control unit transfers injection timing information to the first control unit over the communication bus.

### Claim 12

A control system for an engine comprising:
a first fuel injector;
a first connection connected with the first fuel injector;
a first control unit connected with the first connection and programmed to generate a first pulse width, which in operation is delivered to the first fuel injector over the first connection to actuate the first fuel injector to introduce a first fuel;
a second fuel injector;
a second connection connected with the second fuel injector;
a second control unit connected with the second connection and programmed to generate a second pulse width delivered over the second connection to actuate the second fuel injector to introduce a second fuel; and
a communication bus allowing the first and second control units to exchange information;
wherein the first control unit is further programmed to determine a total fuel energy amount to be introduced by the first and second fuel injectors and to transfer the total fuel energy amount to the second control unit over the communication bus;
wherein the second control unit is further programmed to determine a first fraction of the total fuel energy amount to be from the first fuel and a second fraction of the total fuel energy amount to be from the second fuel, and
wherein the second control unit transfers at least one of the first fraction and the second fraction to the first control unit over the communication bus.

### Claim 13 (depends on 12)

The control system of claim 12, wherein the first control unit is further programmed to calculate a third quantity of the first fuel to be injected by the first fuel injector and a fourth quantity of the second fuel to be injected by the second fuel injector, and the first control unit transfers the fourth quantity to the second control unit over the communication bus.

### Claim 14

A control system for an engine comprising:
a first control unit programmed to generate a first pulse width to actuate a first fuel injector to introduce a first fuel;
a. second control unit programmed to generate a second pulse width to actuate a second fuel injector to introduce a second fuel; and
a communication line allowing the first and second control units to exchange information;
wherein the first control unit is further programmed to:
determine a fuel mass as a function of engine operating conditions representative of a first quantity or the first fuel and a second quantity of the second fuel whereby a first energy amount of the first quantity equals a second energy amount of the second quantity within a predetermined range of tolerance; and
transfer the fuel mass to the second control unit over the communication line;
wherein the second control unit is further programmed to determine a fuel fraction as a function of at least one of the fuel mass, engine operating conditions, properties of the first fuel and properties of the second fuel, the fuel fraction representative of a third quantity of the first fuel and a fourth quantity of the second fuel, the first energy amount is equal to a sum of a third energy amount of the third quantity of the first fuel and a fourth energy amount of the fourth quantity of the second fuel within a predetermined range of tolerance;
wherein the first pulse width is determined as a function of the third quantity of the first fuel and the second pulse width is determined as a function of the fourth quantity of the second fuel.

### Claim 15 (depends on 14)

The control system of claim 14, wherein at least one of:
the first fuel injector introduces the first fuel into an intake manifold of the engine; and
the second fuel injector introduces the second fuel into the intake manifold of the engine.

### Claim 16 (depends on 14)

The control system of claim 14, wherein the second control unit is further programmed to:
transfer the fuel fraction to the first control unit; and
calculate the fourth quantity of the second fuel as a function of at least two of the fuel mass, the fuel fraction and properties of the second fuel; and
the first control unit is further programmed to calculate the third quantity of the first fuel as a function of at least two of the fuel mass, the fuel fraction and properties of the first fuel.

### Claim 17 (depends on 14)

The control system of claim 14, wherein the second control unit is further programmed to:
calculate the third quantity of the first fuel as a function of at least two of the fuel mass, the fuel fraction and properties of the first fuel;
calculate the fourth quantity of the second fuel as a function of at least two of the fuel mass, the fuel fraction and properties of the second fuel; and
transfer the third quantity of the first fuel to the first control unit.

### Claim 18 (depends on 14)

The control system of claim 14, wherein the fuel fraction is any parameter such that the third quantity of the first fuel and the fourth quantity of the second fuel can be determined based on the fuel mass, the properties of the first fuel and the properties of the second fuel.

### Claim 19 (depends on 14)

The control system of claim 14, wherein the fuel fraction is one of a first fraction of the first quantity, a second fraction of the second quantity, the third quantity, the fourth quantity, a first fraction of the first energy amount, a second fraction of the second energy amount, the third energy amount, the fourth energy amount, a ratio between the third and fourth quantities, and a ratio between the third and fourth energy amounts.

### Claim 20 (depends on 1)

The control system of claim 1, wherein at least one of:
the first fuel injector, in operation, directly introduces the first fuel into a combustion chamber of the engine; and
the second fuel injector, in operation, directly introduces the second fuel into the combustion chamber.

### Claim 21 (depends on 1)

The control system of claim 1, wherein the first control unit directly actuates the first fuel injector via the first connection.