Jason L Kraft

US Patent:

20180128607, May 10, 2018

Filed:

Nov 9, 2017

Appl. No.:

15/808311

Inventors:

- Cleveland OH, US
Michael Berne Rannow - Eden Prairie MN, US
Jason Kraft - Stillwater MN, US
Shelley Allison Nation - Bloomington MN, US

International Classification:

G01B 13/20
G01F 1/36

Abstract:

Systems and methods for estimating the area ratio of an actuator in static and dynamic states are disclosed. In one aspect, a metering valve is connected to each side of the actuator. In one example, one metering valve is held closed while the other metering valve incrementally pressurizes the actuator in discrete steps. The resulting work port pressures can be used to determine the actuator area ratio. Where counterbalance valves are installed in the system, the pressurizing metering valve can be placed in a pressure control mode to obtain the desired pressure values. In one example, the ratio of flows through each metering valve is used to determine the actuator ratio.

US Patent:

20170023349, Jan 26, 2017

Filed:

Jun 28, 2016

Appl. No.:

15/195450

Inventors:

- Cleveland OH, US
Stephen D. Smith - Plymouth MN, US
Jason T. Kraft - Stillwater MN, US

International Classification:

G01B 7/14
F15B 19/00
G01L 27/00

Abstract:

An online method for reconfiguring pressure and position sensors in a hydraulic system is disclosed. In one step, a sensor drift condition, a recalibration request, or an unisolated fault condition is detected. In another step, a system pressure sensor or another sensor, such as a load-sense pressure sensor, is verified as a trusted master reference sensor. Another step includes measuring and recording a first pressure reading at the master reference sensor and first voltage readings associated with first, second, third, and fourth pressure slave sensors at a first pump pressure set point. Another step includes, repeating the previous step at a second pump pressure set point. A new gain and offset for each of the first, second, third, and fourth pressure sensors can be calculated based on a comparison of the recoded first and second pressure readings and the recorded first and second voltage readings.