Hydraulic Switching Control Supplementing Speed Variable Hydraulic Drives
Primary control of linear motion by variable speed electric motors driving a hydraulic cylinder via a constant displacement pump is an established and successful concept with a frequent use in industry. One problem arises when low or zero motion speed has to be realized under high pump pressure cond...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-12-01
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| Series: | Actuators |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-0825/9/4/129 |
| _version_ | 1797545753062670336 |
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| author | Philipp Zagar Helmut Kogler Rudolf Scheidl Bernd Winkler |
| author_facet | Philipp Zagar Helmut Kogler Rudolf Scheidl Bernd Winkler |
| author_sort | Philipp Zagar |
| collection | DOAJ |
| description | Primary control of linear motion by variable speed electric motors driving a hydraulic cylinder via a constant displacement pump is an established and successful concept with a frequent use in industry. One problem arises when low or zero motion speed has to be realized under high pump pressure conditions. Such load scenarios occur frequently in certain pressing processes, e.g., for sintering or veneering. Most pumps have a lower speed limit, below which critical tribological conditions occur which impair lifespan and efficiency. In addition, pump speed control and pump fluctuation suffer from the mixed lubrication conditions in such an operation range. For a circumvention of such low speed pump operation, a digital valve control concept is presented and studied in this paper. Valve control is used in load holding phases with low speed. Pressure is provided by an accumulator which is charged by the pump in short charging cycles at reasonable pump speeds. It is shown that the mean control error during load holding phase lies within the desired band and the fluctuations of the control force are lower than those of the pump control. In addition, the unfavorable pump operation conditions can be avoided via digital control. |
| first_indexed | 2024-03-10T14:20:28Z |
| format | Article |
| id | doaj.art-608eda8f70b9468d9fa8108585662c0a |
| institution | Directory Open Access Journal |
| issn | 2076-0825 |
| language | English |
| last_indexed | 2024-03-10T14:20:28Z |
| publishDate | 2020-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Actuators |
| spelling | doaj.art-608eda8f70b9468d9fa8108585662c0a2023-11-20T23:27:51ZengMDPI AGActuators2076-08252020-12-019412910.3390/act9040129Hydraulic Switching Control Supplementing Speed Variable Hydraulic DrivesPhilipp Zagar0Helmut Kogler1Rudolf Scheidl2Bernd Winkler3Institute of Machine Design and Hydraulic Drives, Johannes Kepler University Linz, 4040 Linz, AustriaLinz Center of Mechatronics GmbH, 4040 Linz, AustriaInstitute of Machine Design and Hydraulic Drives, Johannes Kepler University Linz, 4040 Linz, AustriaLinz Center of Mechatronics GmbH, 4040 Linz, AustriaPrimary control of linear motion by variable speed electric motors driving a hydraulic cylinder via a constant displacement pump is an established and successful concept with a frequent use in industry. One problem arises when low or zero motion speed has to be realized under high pump pressure conditions. Such load scenarios occur frequently in certain pressing processes, e.g., for sintering or veneering. Most pumps have a lower speed limit, below which critical tribological conditions occur which impair lifespan and efficiency. In addition, pump speed control and pump fluctuation suffer from the mixed lubrication conditions in such an operation range. For a circumvention of such low speed pump operation, a digital valve control concept is presented and studied in this paper. Valve control is used in load holding phases with low speed. Pressure is provided by an accumulator which is charged by the pump in short charging cycles at reasonable pump speeds. It is shown that the mean control error during load holding phase lies within the desired band and the fluctuations of the control force are lower than those of the pump control. In addition, the unfavorable pump operation conditions can be avoided via digital control.https://www.mdpi.com/2076-0825/9/4/129speed variable pump controldigital hydraulicspress driveload holding |
| spellingShingle | Philipp Zagar Helmut Kogler Rudolf Scheidl Bernd Winkler Hydraulic Switching Control Supplementing Speed Variable Hydraulic Drives Actuators speed variable pump control digital hydraulics press drive load holding |
| title | Hydraulic Switching Control Supplementing Speed Variable Hydraulic Drives |
| title_full | Hydraulic Switching Control Supplementing Speed Variable Hydraulic Drives |
| title_fullStr | Hydraulic Switching Control Supplementing Speed Variable Hydraulic Drives |
| title_full_unstemmed | Hydraulic Switching Control Supplementing Speed Variable Hydraulic Drives |
| title_short | Hydraulic Switching Control Supplementing Speed Variable Hydraulic Drives |
| title_sort | hydraulic switching control supplementing speed variable hydraulic drives |
| topic | speed variable pump control digital hydraulics press drive load holding |
| url | https://www.mdpi.com/2076-0825/9/4/129 |
| work_keys_str_mv | AT philippzagar hydraulicswitchingcontrolsupplementingspeedvariablehydraulicdrives AT helmutkogler hydraulicswitchingcontrolsupplementingspeedvariablehydraulicdrives AT rudolfscheidl hydraulicswitchingcontrolsupplementingspeedvariablehydraulicdrives AT berndwinkler hydraulicswitchingcontrolsupplementingspeedvariablehydraulicdrives |