APPARATUS AND METHOD FOR CONTROLLING THE SPEED OF AN INTERNAL COMBUSTION ENGINE

• US 20110247588A1
• Filed: 12/15/2009
• Published: 10/13/2011
• Est. Priority Date: 12/31/2008
• Status: Active Grant

• Current Assignee: Wartsila Italia SPA (Wärtsilä Corporation)
• Original Assignee: Wartsila Italia SPA (Wärtsilä Corporation)
• Inventors: Kaas, Tom, Pensar, Johan, Troberg, Tom
• Granted Patent: US 8,494,755 B2
• Time in Patent Office: Days
• US Class Current: 123/395
• CPC Class Codes: F02D 2041/1409 using at least a proportional, integral or derivative controller
• CPC Class Codes: F02D 2041/141 using a feed-forward control element
• CPC Class Codes: F02D 2041/1418 Several control loops, either as alternatives or simultaneous
• CPC Class Codes: F02D 2041/1432 the system including a filter, e.g. a low pass or high pass filter
• CPC Class Codes: F02D 31/007 controlling fuel supply
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02D 41/0085 Balancing of cylinder outputs, e.g. speed, torque or air-fuel ratio
• CPC Class Codes: F02D 41/1401 characterised by the control or regulation method F02D41/1473, F02D41/1477 take precedence
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue

Abstract

The apparatus according to the invention comprises a controller for forming a speed signal arranged to receive speed measurement data of the internal combustion engine as well as speed reference data. The apparatus additionally comprises a module for forming the internal speed reference value instead of the speed reference value set to be used when forming the control signal.

Claims

1. A method of controlling the speed of an internal combustion engine, comprising steps of:

measuring speed of the internal combustion engine and forming a control signal as a response to the measurement and a set speed reference value,

characterized in that the method also comprises a step of forming an internal speed reference value by utilizing control signal data, for using in place of the set speed reference value when forming the control signal, the step of forming the internal speed reference value comprising a function for reducing effect of the set reference value in the internal speed reference value by subtracting from the set reference value a certain subtraction part that depends on the value of the control signal by certain criteria.

2. A method according to claim 1, characterized in that the subtraction part is arranged to be formed by multiplying the set speed reference value, the control signal value and a certain coefficient.

3. A method according to any of claims 1-2, characterized in that the control signal represents the duration of the fuel injection of the cylinder.

4. An apparatus for controlling speed of an internal combustion engine, the apparatus comprising a controller for forming a control signal, the controller being arranged to receive speed data of the internal combustion engine and which has a set speed reference value, characterized in that the apparatus also comprises a module for forming an internal speed reference value for using in place of the set speed reference value when forming the control signal, the module being arranged to use the set speed reference value and the control signal value for forming the internal speed reference value, the module comprising a submodule for reducing effect of the set reference value in the internal speed reference value, the submodule being arranged to subtract a certain subtraction part of the set reference value, the part being dependent on the value of the control signal under certain criteria.

5. An apparatus according to claim 4, characterized in that the subtraction part is arranged to be formed by multiplying the set speed reference value, the control signal value and a certain coefficient.

6. An apparatus according to any of claims 4-5, characterized in that the control signal represents the duration of the fuel injection of the cylinder.

7. An apparatus according to any of claims 4-6, characterized in that the apparatus is a cylinder controller module.

8. An apparatus according to any of claims 4-5, characterized in that the control signal is arranged to be processed in a low-pass filter prior to its use in the module.