# US 4,391,248 A · Method for closed-loop control of the ignition angle or the composition of the operational mixture furnished an internal combustion engine

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,391,248 A
- Document ID: US4391248A
- Status: Granted
- Kind: A
- Application number: 06/191,743
- Filed: 1980-09-29
- Granted: 1983-07-05
- Earliest claimed: 1979-09-29
- Assignees: Robert Bosch GmbH
- Inventors: Reinhard Latsch
- Web page: https://patentgrep.com/patent/US4391248A

## CPC

- F02D 41/345: {Controlling injection timing (F02D41/365 takes precedence)}
- F02D 35/00: Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
- F02D 41/1497: {With detection of the mechanical response of the engine}
- F02P 5/1455: {by using a second control of the closed loop type (dependent on pinking F02P5/152)}
- 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)
- F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A method is proposed for the closed-loop control of the composition of the operational mixture furnished an internal combustion engine, in which the location of the peak combustion chamber pressure is ascertained relative to top dead center during sequential work cycles and a control signal is formed from the fluctuations in the occurrance of the peak combustion chamber pressure from top dead center, by means of which control signal a permissible extent of fluctuation is established by means of influencing components of the operational mixture or the ignition angle.

## Claims

### Claim 1

A method of closed-loop control for the composition of an operational mixture furnished to an internal combustion engine for combustion therein, comprising the steps of:
ascertaining the occurrence of the top dead center in sequential work cycles of at least one combustion chamber of the engine;
measuring the magnitude of the combustion chamber pressure of said at least one combusting chamber with a pressure probe;
ascertaining the occurrence of the peak combustion chamber pressure from the measured magnitude of the combustion chamber pressure, relative to the ascertained top dead center occurrence in sequential work cycles of said at least one combustion chamber;
generating a control signal as a function of the difference between two successive occurrences of the peak combustion chamber pressure relative to the occurrence of the top dead center in sequential work cycles of said at least one combustion chamber;
generating a set-point value for the control signal;
comparing the generated control signal to the generated set-point value and generating a difference signal; and
adjusting the proportion of at least one component of the operational mixture in accordance with the generated difference signal.

### Claim 2 (depends on 1)

The method as defined in claim 1, wherein the top dead center in the sequential work cycles of said at least one combustion chamber is ascertained by monitoring engine crankshaft rotation, wherein the measured magnitude of the combustion chamber pressure is matched with the monitored engine crankshaft rotation in sequential work cycles of said at least one combustion chamber, and wherein the control signal represents the difference in crankshaft angle between top dead center and the peak pressure occurrence.

### Claim 3 (depends on 2)

The method as defined in claim 2, wherein the occurrence of the peak combusting chamber pressure is ascertained by differentiating the output of the pressure probe.

### Claim 4

A method of closed-loop control of the ignition angle of an internal combustion engine comprising the steps of:
ascertaining the occurrence of the top dead center in sequential work cycles of at least one combustion chamber of the engine;
measuring the magnitude of the combustion chamber pressure of said at least one combustion chamber with a pressure probe;
ascertaining the occurrence of the peak combustion chamber pressure from the measured magnitude of the combustion chamber pressure, relative to the ascertained top dead center occurrence in sequential work cycles of said at least one combustion chamber;
generating a control signal as a function of the difference between two successive occurrences of the peak combustion chamber pressure relative to the occurrence of the top dead center in sequential work cycles of said at least one combustion chamber;
generating a set-point value for the control signal;
comparing the generated control signal to the generated set-point value and generating a difference signal; and
adjusting the ignition angle in accordance with the generated difference signal.

### Claim 5 (depends on 4)

The method as defined in claim 4, wherein the top dead center in the sequential work cycles of said at least one combustion chamber is ascertained by monitoring engine crankshaft rotation, wherein the measured magnitude of the combustion chamber pressure is matched with the monitored engine crankshaft rotation in sequential work cycles of said at least one combustion chamber, and wherein the control signal represents the difference in crankshaft angle between top dead center and the peak pressure occurrence.

### Claim 6 (depends on 4)

The method as defined in claim 4, wherein the occurrence of the peak combusting chamber pressure is ascertained by differentiating the output of the pressure probe.