Vehicle accessory control system

• US 4,642,770 A
• Filed: 04/18/1985
• Issued: 02/10/1987
• Est. Priority Date: 04/18/1985
• Status: Expired due to Term

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Shirley, Ralph E.
• Primary Examiner(s): Chin, Gary
• Application Number:
  US06/724,427
• Time in Patent Office: 663 Days
• Field of Search: 364/418, 364/424, 364/557, 364/558, 340/52 R, 340/57, 165/12, 165/42-43, 62/133, 62/230, 62/231, 62/243, 62/323.1, 62/323.4
• US Class Current: 701/36
• CPC Class Codes: B60H 1/3208 Vehicle drive related control of the compressor drive means, e.g. for fuel saving purposes
• CPC Class Codes: G05D 23/1917 using digital means

Abstract

A control system for engine-driven vehicle accessories generates sets of values representing a recent history of the engine loading and of the operational status of the accessories. History factors are derived from the sets of values. The accessories are controlled as a function of sensed parameters and of comparisons between the history factors. The sets of values are periodically updated.

Claims

1. A method for controlling the operation of an accessory driven by a vehicle engine, comprising:

(a) periodically sensing loading of the engine and generating a plurality of engine load values representing the periodically sensed engine load;

(b) storing a set of said load values in a corresponding first set of memory locations;

(c) deriving an engine loading factor from the set of stored load values;

(d) storing a set of activity values in a corresponding second set of memory locations, each activity value representing an activity status of the engine driven accessory;

(e) deriving an accessory activity factor from the set of stored activity values;

(f) comparing the engine loading factor with the accessory activity factor; and

(g) activating or deactivating the accessory, depending upon the result of the comparison.

2. The method of claim 1, wherein:

the engine loading factor represents the number of the stored load values which are exceeded by a certain engine load value.

3. The method of claim 1, wherein:

the accessory activity factor represents the number of the stored activity values which are equal to a certain value.

4. The method of claim 1, further comprising:

after activating or deactivating the accessory, replacing an oldest one of the stored activity values with a new activity value representing the activity status of the accessory resulting from operation of step "(g)",

5. The method of claim 4, further comprising:

periodically replacing an oldest one of the stored engine load values with a most recent one of the load values generated by operation of step "(a)".

6. The method of claim 1, further comprising:

periodically sensing a temperature of the engine;

comparing the sensed temperature to a limit temperature; and

activating or deactiviating the accessory, depending upon the relationship between the sensed and limit temperatures.

7. The method of claim 1, wherein:

the accessory is an alternator which charges a vehicle battery, the alternator having a rotating field coil.

8. The method of claim 7, further comprising:

periodically sensing a voltage of the battery; and

energizing or de-energizing the field coil, depending upon a relationship between the sensed voltage and a limit voltage.

9. The method of claim 8, further comprising:

storing a set of energization values in a corresponding third set of memory locations, each energization value representing an energization status of the field coil;

deriving an energization factor from the set of stored energization values; and

energizing or de-energizing the field coil, depending upon a relationship between the engine loading factor and the energization factor.

10. The method of claim 9, further comprising:

after energizing or de-energizing the field coil, replacing an oldest one of the stored energization values with a new energization value representing the current energization status of the field coil.

11. The method of claim 1, wherein:

the accessory is an air compressor which pressurizes an accumulator.

12. The method of claim 1, further comprising:

periodically sensing a pressure in the accumulator; and

activating or de-activating the air compressor, depending upon a relationship between the sensed pressure and a limit pressure.

13. The method of claim 12, further comprising:

storing a set of operating values in a corresponding set of memory locations, each operating value representing an operational status of the air compressor;

deriving an air compressor operating factor from the set of stored operating values;

operating or disabling the air compressor, depending upon a relationship between the air compressor operating factor and the engine loading factor; and

after operating or disabling the air compressor, replacing an oldest one of the stored operating values with a new operating value representing the current operational status of the air compressor.

14. The method of claim 1, wherein:

the accessory is an engine-driven air conditioner compressor for compressing refrigerant in a vehicle air conditioning system which conditions an operator'"'"'s compartment.

15. The method of claim 14, further comprising:

periodically sensing a temperature of the operator'"'"'s compartment; and

activating or de-activating the air conditioner compressor, depending upon a relationship between the sensed temperature and a limit temperature.

16. A method for controlling the operation of a vehicle air conditioning compressor driven by an engine via engageable and disengageable clutch, the method comprising:

(a) periodically sensing loading of the engine and generating a plurality of engine load values, each representing the engine loading at a particular instant;

(b) storing a set of said load values in a corresponding first set of memory locations;

(c) deriving an engine loading factor from the set of stored load values;

(d) storing a set of engagement values in a corresponding set of memory locations, each engagement value representing an engagement status of the clutch at a certain instant;

(e) deriving an engagement history factor from the set of stored engagement values;

(f) comparing the engine loading factor with the engagement history factor; and

(g) controlling engagement of the clutch, depending upon the relationship between the compared factors.

17. The method of claim 16, wherein:

the engine loading factor represents the number of the stored load values which are exceeded by the engine load value most recently generated by step "(a)"; and

the engagement history factor represents the number of stored engagement values which are equal to a certain value.