×

Table look-up method with adaptive hashing

  • US 7,539,661 B2
  • Filed: 06/02/2005
  • Issued: 05/26/2009
  • Est. Priority Date: 06/02/2005
  • Status: Active Grant
First Claim
Patent Images

1. A method of controlling a system using control data stored in a data table within a controller memory unit indexed as a function of a measurable parameter of the system, the method comprising the steps of:

  • establishing a hash table in said memory unit having hash index values;

    linking various values of said measurable parameter to said hash index values with a hash function;

    forming key elements for each of the linked values of said measurable parameter, each key element including a hash index value, an index value for said data table and a weight value;

    selecting for inclusion in the hash table only key elements for which said weight value exceeds a specified weight, and chaining the selected key elements to a respective hash index value in said hash table;

    obtaining a sample of said measurable parameter;

    determining a hash index value corresponding to said sample, probing the key elements chained to the determined hash index to locate a key element for said sample, and locating control data stored for said sample using a data table index value of the located key element;

    probing said data table to locate the control data for said sample if a key element for said sample is not located in said hash table; and

    controlling said system using the located control data.

View all claims
  • 5 Assignments
Timeline View
Assignment View
    ×
    ×