The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 13, 2015
Filed:
May. 06, 2011
Hongliu Du, Naperville, IL (US);
Patrick W. Sullivan, Tinley Park, IL (US);
Hongliu Du, Naperville, IL (US);
Patrick W. Sullivan, Tinley Park, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A method and apparatus for controlling discharge pressure and pump displacement of a plurality of variable displacement hydraulic pumps having connected discharge ports is provided. Each pump includes a swashplate and a control valve for controlling an angle of inclination of the swashplate. A desired first pump displacement control law is determined for a first pump and determined a desired second pump discharge pressure control law for a second pump. The first control law is used to determine a first intermediate control variable. The second control law is used to determine a second intermediate control variable. The control of the first and second pumps are combined using the first and second intermediate control variables. A desired first control valve setting for the control valve of the first pump is determined using the combined first and second intermediate control variables and the first control law. A desired second control valve setting for the control valve of the second pump is determined using the combined first and second intermediate control variables and the second control law.