Post on 10-Apr-2022
Towards more efficient mobile Hydraulic Systems
Petter KrusDivision of Fluid and Mechatronic SystemsDepartment of Management and Engineering
2
Linköping University• Sweden 9.5 million people
• Linköping Municipality 140 000 people
• Linköping University 27 000 students
Linköping, Sweden
Linköping Malmen
Birthplace of Swedish Aviation 1911
Carl Cederström 1912
Petter Krus
2018-12-07Linköpings universitet
Sid 5
Mechatronics
Aircraft design
Design analysis and optimisation
Modelling and simulation
Aircraft Systems Fluid Power
Embedded systems
Flumes Research Areas
Systems Engineering
MechatronicSystems
Onboard systems
Subscale flight testing
Measurement and control systems
Hydraulic system and component design
Mobile systemsSensor systems
Noise and vibrations
Some Industrial Partners andApplications
2018-12-07 Sid 6
Construction MachinesVolvo CE
AircaftSaab AB
Rock drillsEpiroc(formerly Atlas Copco)
HOPSAN-NG (Next Generation)
• Bidirectional delay-lines
• Modelica support is under development
• Genuine team work
• Freeware that can be downloaded from http://www.iei.liu.se/flumes/system-simulation/hopsanng
Petter Krus
Friday afternoon workshop= “happy hour”
Open Centre SystemPetter Krus
Load Sensing System Petter Krus
Negative Load Sensing System
Pump is regulated to keep the flow in the opencentre constant
Petter Krus
Related Systems• Open flow control
– Feed forward control of pump displacement from sum of flow demands.
Petter Krus
Energy Efficiency
Pressure
Pressure Flow
FlowLoad Sensing
Open Centre
Petter Krus
Energy Efficiency
Pressure
Pressure Flow
FlowLoad Sensing
Constant pressure
Petter Krus
General system configuration for a hydraulic transmission (motor or cylinder)
14
sp
vx
M
Lp
P
,P PTLT
,M MT
vx vx
Losses in combustion
engine
Losses in pumps and
motors
Throttling losses
Gravity losses,
active
Idling losses
Gravity losses,
passive
Petter Krus
Open centre system (motor or cylinder)
15
sp
vx
Lp
,P PTLT
,M MT
vx vx
Losses in combustion
engine
Losses in pumps and
motors
Throttling losses
Idling losses
Petter Krus
Pump controlled constant pressure system
16
Losses in combustion
engine
Losses in pumps and
motors
Throttling losses
Idling losses
sp
vx
Lp
P
,P PTLT
,M MT
vx
Petter Krus
Load sensing or open flow control (motor or cylinder)
17
sp
vx
Lp
P
,P PTLT
,M MT
vx
Losses in combustion
engine
Losses in pumps and
motors
Throttling losses
Idling losses
Petter Krus
vx
vx
Pump controlled motor (or cylinder)
18
spLp
P
,P PTLT
,M MT
vx
Losses in combustion
engine
Losses in pumps and
motors
Idling losses
Petter Krus
Secondary control (over-center controlled motor). Common rail. Energy recuperation
19
Losses in combustion
engine
Losses in pumps and
motors
Idling losses
sp
M
Lp
,P PTLT
,M MT
P
Petter Krus
Secondary control (over-center controlled motor). Common rail. Electric motor control.
20
Losses in combustion
engine
Losses in pumps and
motors
Idling losses
sp
M
Lp
,P PTLT
,M MT
P
M
Petter Krus
Fluid Power Systems for Working Machineryvariable area cylinders!
2018-12-07 21Kim Heybroek
Fuel efficiency (ton/liter)
2018-12-07 22Kim Heybroek
Fluid Power Systems for Working Machinery
2018-12-07 23Kim Heybroek
Cost/Complexity
Fue
l Eff
icie
ncy
Independent meter-in and meter-out
• Minimize pressure on the low pressure side can reduce lossesdepending on load cycles
• Flow can be drawn from tank (instead of pump) when lowering a load.
• Opening both sides to pressure give a high speed mode.
• Identical elements can be used. No tuning. Less articles in inventory.
2018-12-07 24Title/Lecturer
sp
vx
Rp
LF
sp
Ap Bp
Rp
LF
Four individual metering
• Allows for use of seat valves
• Four identical elements. Larger series of valves.
2018-12-07 25Petter Krus
spRp
ApBp
LF
2018-12-07 25
Force
Three chamber cylinder(or more)
• Can be used for ”digital hydraulics” or multi mode hydraulics. ”Variable area cylinder”.
2018-12-07 26Petter Krus
Rp
ApBp
LFCp
sp
Force
0
0
0
2
4
C
B
A
A A
A A
A A
=
=
=
Three chamber cylinder(or more)
• Can be used for ”digital hydraulics” or multi mode hydraulics. ”Variable area cylinder”.
2018-12-07 27Petter Krus
Rp
ApBp
LFCp
sp
Force
0
0
0
2
4
C
B
A
A A
A A
A A
=
=
=
Three chamber cylinder(or more)
• Can be used for ”digital hydraulics” or multi mode hydraulics. ”Variable area cylinder”.
2018-12-07 28Petter Krus
Rp
ApBp
LF
Rp
Cp
Force
sp
0
0
0
2
4
C
B
A
A A
A A
A A
=
=
=
Electrified Hydraulics for Vehicles
29
Potential:
80% less energy consumption
Around 8% fuelsaving, overall.
The HILA TechnologyMagnus Landberg
▪ EXTENDED WORKING RANGE
- Long piston rods open up new areas and applications
for hydraulic cylinders for example in elevators in high
rises, additive manufacturing, AS/RS, Gantry robots,
CNC machines, etc.
▪ INCREASED CONTROL STABILITY
- Higher stiffness, higher natural frequency and higher
system pressure
▪ COMPACTNESS
– Much shorter and lighter cylinder and a higher
system pressure - > Significant reductions in weight
and volume, more cost-efficient and compact overall
system designs, especially reservoirs.
A hydraulic actuator invention that allows very long strokes!
HILATM
(HILA = Hydraulic Infinite Linear Actuator, see animation on Youtube: HILA - How it works)
▪ EXAMINED IN A BRAND
NEW DISSERTATION
▪ PROOF OF CONCEPT
- Successful tests with a vertical load (400 kg),
in FLUMES hydraulic lab at Linköping University,
sponsored by the Swedish Energy Agency.
▪ PATENTED TECHNOLOGY
Linear Incremental Hydraulic Actuator
Martin Hochwallner
Characteristic: Long Stroke
• Incremental motion: No conceptual limit in stroke length
Martin Hochwallner
Characteristic: Hybrid System
3 (1) DoFs, temporarily coupled2 (1) continuous control inputs2 (0) discrete control inputs
Martin Hochwallner
Gait -- Smooth Motion
Martin Hochwallner
Gait -- Ballistic Gait
Martin Hochwallner
Gait -- Ballistic Gait
time in sec
Martin Hochwallner
Digitalization
• Whats new?
• Cost of anything electronic is going down, including sensors and communication.
• IoT, Big data allows for condition monitoring and prognostics on a new scale. Also to establish much more precise requirements for new designs.
• Safety regulations in Europe is requiring sensors for e.g. pressure and position the hence is ”free” for other functions thatnow can be implemented. E.g. crane tip control.
• 3D printing will allow for new more efficient geometries and for a different supply chain.
Petter Krus
Summary
Loadsensing
Individualmetering
Integratedcontrol drivelinework hydraulics
Electric pumps
Multi chambercylinders
Open flowcontrol
Petter Krus
Efficiency
Cost
Electric pump controlledcylinders
Conclusions: Is there a future for Fluid Power?
• Yes!
2018-12-07 44Title/Lecturer