Input signal processor used in electronic engine control apparatus

• US 4,280,189 A
• Filed: 10/18/1978
• Issued: 07/21/1981
• Est. Priority Date: 10/19/1977
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Furuhashi, Toshio, Takato, Masao, Imai, Masumi
• Primary Examiner(s): Gruber, Felix D.
• Application Number:
  US05/952,275
• Time in Patent Office: 1,007 Days
• Field of Search: 364/424, 364/431, 364/442, 364/724, 364/734, 123/416, 123/417, 123/480, 123/494
• US Class Current: 708/445
• CPC Class Codes: F02D 41/26 using computer, e.g. microprocessor
• CPC Class Codes: F02D 41/28 Interface circuits
• CPC Class Codes: F02P 5/045 combined with electronic control of other engine functions, e.g. fuel injection in general F02D37/02
• CPC Class Codes: F02P 5/1502 using one central computing unit
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An input signal processor used in the control apparatus for an internal combustion engine of automobiles, the apparatus being equipped with an electronic computer, wherein the ripple components contained in a signal sampled with a constant period, e.g. a signal representing the air flow rate and the rotational speed of the engine, are eliminated through a predetermined arithmetic process by the use of an unprocessed signal x_i at an instant t_i and the signal y_i-1 already processed at the instant t_i-1 so that an optimal control of the internal combustion engine matched to all driving conditions of the automobile can be performed by using the processed signal without any ripple component.

Claims

1. In a control apparatus for an internal combustion engine having:

sensor means for monitoring operating conditions of the engine and producing signals, including any ripple components, representative thereof;

conversion means for converting the signals produced by said sensor means into digital data representative thereof;

actuator means for controlling respective energy conversion functions of said engine in response to control signals applied thereto; and

a data processing unit for carrying out engine actuator control data processing operations in accordance with digital data produced by said conversion means and thereby generating output control signals to be coupled to control said actuator means in accordance with the results of said data processing operations, said data processing unit containing a central processing unit, a random access memory and a read only memory;

a method of operating said apparatus, so as to remove any ripple components present in signals X produced by said sensor means and correspondingly converted into digital data by said conversion means, so as to obtain filtered signals Y in response to which said data processing unit operates in carrying said engine actuator control data processing operations, comprising the steps of;

sampling the digital data produced by said conversion means at periodic instants in time t_i, to obtain for each sampling time a first digital signal sample X_i representative of the output of said actuator means including any ripple data for that respective sampling time t_i, and storing a physical record of said digital signal sample X_i in said random access memory;

storing in said random access memory a physical record of the results of a prescribed filtering process operation through which a filtered signal sample Y_i is derived by said central processing unit in response to said sample X_i and a previously-derived filtered sample Y_i-1 for a digital signal sample X_i-1 at sampling time t_i-1 ;

applying a previously-derived and stored filtered sample Y_i-1 and said first digital signal sample X_i from said random access memory to said central processing unit wherein a filtered signal sample Y_i for said sampling time t_i is obtained in accordance with a prescribed relationship between said digital signal sample X_i and said stored previously-derived filtered sample Y_i-1 for the previous sampling time t_i-1 ;

storing a physical record of said filtered signal sample Y_i in said random access memory;

generating output control signals by coupling said filter signal sample Y_i to said data processing unit in which engine actuator control data processing operations are carried out; and

causing said output control signals to be coupled to said actuator means whereby said respective energy conversion functions of said engine are controlled.

2. A method of operating a control apparatus according to claim 1, wherein said prescribed relationship defines Y_i by the expression Y_i =α

·

X_i +(1-α

)·

Y_i-1, wherein 0≦

α

≦

1.0.

3. A method of operating a control apparatus according to claim 2, wherein said expression is calculated by said central processing unit in accordance with an exponential averaging method with respective values of α

·

2^m and (1-α

)·

2^m being stored in said read only memory, m being a positive integer.

4. A method of operating a control apparatus according to claim 1, wherein said sensor means includes means for producing a signal representative of the flow rate of intake air to the engine.

5. A method of operating a control apparatus according to claim 1, wherein said sensor means includes means for producing a signal representative of the negative pressure in the intake manifold of the engine.

6. A method of operating a control apparatus according to claim 1, wherein said sensor means includes means for generating pulses in synchronism with a predetermined degree of rotation of the engine crankshaft.

7. In a control apparatus for an internal combustion engine having:

sensor means for monitoring operating conditions of the engine and producing signals, including any ripple components, representative thereof;

conversion means for converting the signals produced by said sensor means into digital data representative thereof;

actuator means for controlling respective energy conversion functions of said engine in response to control signals applied thereto; and

a data processing unit for carrying out engine actuator control data processing operations in accordance with digital data produced by said conversion means and thereby generating output control signals to be coupled to control said actuator means in accordance with the results of said data processing operations, said data processing unit containing a central processing unit, a random acess memory and a read only memory;

a method of operating said apparatus, so as to remove any ripple components present in signals X produced by said sensor means and correspondingly converted into digital data by said conversion means, so as to obtain filtered signals Y in response to which said data processing unit operates in carrying said engine actuator control data processing operations, comprising the steps of;

sampling the digital data produced by said conversion means at periodic sampling instants in time, to obtain for each sampling time t_i a digital signal sample X_i representative of the output of said actuator means including any ripple data and storing a physical record of N successive signal samples X_N-i+1 to X_i in said random access memory;

applying the stored (N-1) signal samples X_N-i+1 to X_i-1 and the signal sample X_i to said central processing unit wherein a filtered signal sample Y_i for the sampling time t_i is obtained in accordance with a prescribed relationship among said samples X_N-i+1 to X_i ;

storing a physical record of said filtered signal sample Y_i in said random access memory;

generating output control signals by coupling said filter signal sample Y_i to said data processing unit in which engine actuator control data processing operations are carried out; and

causing said output control signals to be coupled to said actuator means whereby said respective energy conversion functions of said engine are controlled.

8. A method of operating a control apparatus according to claim 7, wherein said defined relationship defines Y_i by the expression ##EQU3## wherein N represents the number of times the arithmetic average is obtained.

9. A method of operating a control apparatus according to claim 8, where N is the form of 2ⁿ, where n is a positive integer.

10. A method of operating a control apparatus according to claim 7, wherein said sensor means includes means for producing a signal representative of the flow rate of intake air to the engine.

11. A method of operating a control apparatus according to claim 7, wherein said sensor means includes means for producing a signal representative of the negative pressure in the intake manifold of the engine.

12. A method of operating a control apparatus according to claim 7, wherein said sensor means includes means for generating pulses in synchronism with a predetermined degree of rotation of the engine crankshaft.

13. In a control apparatus for an internal combustion engine having:

means for producing signals representative of operating conditions of said engine;

conversion means for converting the signals produced by said sensor means into digital data representative thereof;

actuator means for controlling respective energy conversion functions of said engine in response to control signals applied thereto;

an input/output unit coupled to receive signals produced by said sensor means and to deliver control signals to said actuator means, and

a data processing unit, coupled to said input/output unit, for carrying out engine control data processing operations in accordance with digital data produced by said conversion means and thereby generating engine control codes that are coupled to said input/output unit, said data processing unit containing a central processing unit, a random access memory and a read only memory;

said input/output unit comprising;

first means for generating an engine control timing signal pattern through which operational events of said engine are controlled;

second means, coupled to said data processing unit, for storing said engine control codes;

third means, coupled to said first means, for generating respective engine timing codes the values of which are selectively modified by said engine control timing pattern;

fourth means, coupled to said second and third means, for comparing respective ones of said engine control codes with respective ones of said engine timing codes and producing respective output signals when said respective engine control codes define a prescribed relationship with respect to said engine timing codes; and

fifth means, coupled to said fourth means, for producing control signals to be coupled to said actuator means in response to the output signals produced by said fourth means;

a method of operating said apparatus, so as to remove any ripple components present in signals X produced by said sensor means and correspondingly converted into digital data by said conversion means, so as to obtain filtered signals Y in response to which said data processing unit operates in carrying said engine actuator control data processing operations, comprising the steps of;

sampling the digital data produced by said conversion means at respective instants in time t_i, to obtain for each sampling time a first digital signal sample X_i representative of the output of said actuator means including any ripple data for that respective sampling time t_i, and storing a physical record of said digital signal sample X_i in said random access memory;

storing in said random access memory a physical record of the results of a prescribed filtering processing operation through which a filtered signal sample Y_i is derived by said central processing unit in response to said sample X_i and a previously-derived filtered sample Y_i-1 for a digital signal sample X_i-1 at sampling time t_i-1 ;

applying a previously-derived and stored filtered sample Y_i-1 and said first digital signal sample X_i from said random access memory to said central processing unit wherein a filtered signal sample Y_i for said sampling time t_i is obtained in accordance with a prescribed relationship between said digital signal sample X_i and said stored previously-derived filtered sample Y_i-1 for the previous sampling time t_i-1 ;

storing a physical record of said filtered signal sample Y_i in said random access memory;

generating output control signals by coupling said filter signal sample Y_i to said data processing unit in which engine actuator control data processing operations are carried out; and

causing said output control signals to be coupled to said actuator means whereby said respective energy conversion functions of said engine are controlled.

14. A method of operating a control apparatus according to claim 13, wherein said prescribed relationship defines Y_i by the expression Y_i =α

·

X_i +(1-α

)·

Y_i-1, wherein 0≦

α

≦

1.0.

15. In a control apparatus for an internal combustion engine having:

means for producing signals representative of operating conditions of said engine;

conversion means for converting the signals produced by said sensor means into digital data representative thereof;

actuator means for controlling respective energy conversion functions of said engine in response to control signals applied thereto;

an input/output unit coupled to receive signals produced by said sensor means and to deliver control signals to said actuator means, and

a data processing unit, coupled to said input/output unit, for carrying out engine control data processing operations in accordance with digital data produced by said conversion means and thereby generating engine control codes that are coupled to said input/output unit, said data processing unit containing a central processing unit, a random access memory and a read only memory;

said input/output unit comprising;

first means for generating an engine control timing signal pattern through which operational events of said engine are controlled;

second means, coupled to said data processing unit, for storing said engine control codes;

third means, coupled to said first means, for generating respective engine timing codes the values of which are selectively modified by said engine control timing pattern;

fourth means, coupled to said second and third means, for comparing respective ones of said engine control codes with respective ones of said engine timing codes and producing respective output signals when said respective engine control codes define a prescribed relationship with respect to said engine timing codes; and

fifth means, coupled to said fourth means, for producing control signals to be coupled to said actuator means in response to the output signals produced by said fourth means;

a method of operating said apparatus, so as to remove any ripple components present in signals X produced by said sensor means and correspondingly converted into digital data by said conversion means, so as to obtain filtered signals Y in response to which said data processing unit operates in carrying said engine actuator control data processing operations, comprising the steps of;

sampling the digital data produced by said conversion means at successive sampling instants in time, to obtain for each sampling time t_i a digital signal sample X_i representative of the output of said actuator means including any ripple data and storing a physical record of N successive signal samples X_N-i+1 to X_i in said random access memory;

applying the stored (N-1) signal samples X_N-i+1 to X_i-1 and the signal sample X_i to said central processing unit wherein a filtered signal sample Y_i for the sampling time t_i is obtained in accordance with a prescribed relationship among said samples X_N-i+1 to X_i ;

storing a physical record of said filtered signal sample Y_i in said random access memory;

generating output control signals by coupling said filter signal sample Y_i to said data processing unit in which engine actuator control data processing operations are carried out; and

causing said output control signals to be coupled to said actuator means whereby said respective energy conversion functions of said engine are controlled.

16. A method of operating a control apparatus according to claim 15, wherein said defined relationship defines Y_i by the expression ##EQU4## wherein N represents the number of times the arithmetic average is obtained.