Optimization of a Hydraulic
Hybrid Vehicle for On-Road
Driving
Katharina Baer, Liselott Ericson and Petter Krus
Division of Fluid and Mechatronic Systems
Linköping University
Power demand
Hydraulic Hybrids
 Energy recuperation
 Peak-shaving/load leveling
Time
Attractive for industry and research projects
 Hydraulikdagarna 2015
 Center for Compact and Efficient Fluid Power
 passenger vehicles, mobile machinery
2
Hydraulic Hybrids: Some Options
Series
Architectures
Parallel
Power-Split
Vehicle
size
Mobile
Applications
3
Concept Variations
•
Valves
•
Gears
•
Multiple component
instances
•
…
+ Control Concepts
Hybrid Hydraulic Vehicle Modeling:
Point of Departure
4
Application for Hydraulic Hybrid Vehicle
Series
Architectures
Parallel
Power-Split
Vehicle
size
Mobile
Applications
5
Modeling
6
Vehicle Design Optimization
Reference Velocity [km/h]
Urban Dynamometer Driving Schedule
 Sizing of driveline components
 influences vehicle mass
100
50
0
200
400
600
800
1000
1200
1400
Time [s]
100
50
Objective function integrated in
Hopsan model
0
0
200New300
400
European
100
Reference Velocity [km/h]
Reference Velocity [km/h]
0 York City Cycle
New
 Control parameters
(pressure levels)
500
600
Driving
Cycle
Time [s]
150
Build-in optimization function
100
50
0
0
200
400
600
Time [s]
7
800
1000
1200
Results for fuel consumption
140
120
100
80
60
40
20
0
Fuel Consumption NYCC [-]
New York City Cycle
0
200 140400
120
100
80
60
40
20
0
0
600
800
1000
1200
But…
1400
Time [s]
1.30
1.25
1.20
1.15
Design
1.10
NYCC
1.05
UDDS
1.00
0.95
0.95
1.00
1.05
1.10
1.15
Fuel Consumption UDDS [-]
100
200
300
Time [s]
8
Fuel Consumption (relative to optimum)
1.35
Reference Velocity [km/h]
Reference Velocity [km/h]
Urban Dynamometer Driving Schedule
400
500
600
1.20
1.25
Results: combining the driving requirements
Fuel Consumption (relative to optimum)
1.30
1.25
FC(NYCC):FC(UDDS)
1.20
1.0 : 0.0
1.15
0.7 : 0.3
1.10
0.5 : 0.5
1.05
0.3 : 0.7
1.00
0.0 : 1.0
0.95
0.95
1.00
1.05
1.10
1.15
Fuel Consumption UDDS [-]
Fraction of Parameter Range
Fuel Consumption NYCC [-]
1.35
1
0.8
FC(NYCC):FC(UDDS)
0.6
1.0 : 0.0
0.7 : 0.3
0.4
0.5 : 0.5
0.3 : 0.7
0.2
0.0 : 1.0
0
Dp
9
Dpm
phigh
plow
Parameters
pmax
Tmax
V0acc
Iterative Process
Simulation model
model refinement,
model alternatives,
…
Simulation/Optimization Results
10
The Bigger Picture
Series
Concept Variations
•
Valves
•
Gears
•
Multiple component
instances
•
…
+ Control Concepts
Architectures
Parallel
Power-Split
Vehicle
size
Mobile
Applications
11
Additional considerations
….
www.liu.se
Results for fuel consumption
140
120
100
80
60
40
20
0
Fuel Consumption (relative to optimum)
Fuel Consumption NYCC [-]
1.35
New York City Cycle
0
200 140400
120
100
80
60
40
20
0
0
Reference Velocity [km/h]
600
800
1000
1200
1400
Time [s]
1.30
1.25
1.20
1.15
Design
1.10
NYCC
1.05
UDDS
1.00
0.95
0.95
1.00
200
300
400
500
1.10
1.15
1.25
1.0
0.8
NYCC
0.6
0.4
0.2
UDDS
0.0
Dp
Dpm phigh plow pmax Tmax V0acc
Parameter
13
1.20
600
Time [s]
But…
1.05
Fuel Consumption UDDS [-]
100
Fraction of Parameter Range
Reference Velocity [km/h]
Urban Dynamometer Driving Schedule