Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
June 5th, 2019
CCEFP Summit at Purdue in Honor of Monika Ivantysynova
Xin Tian, Josias Cruz [Presenter]
Advisor: Andrea Vacca
MAHA Fluid Power Research Center
Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling 2
Introduction
Current work
System Power Distribution Characterization
System Models Development and Validation
Experimental Tests Set Up
Contents
System Model Validation Results
Conclusion
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
Research motivation
Auxiliary hydraulic functions
Power beyond
Traveling service
Steering
Braking
Introduction Model development Experimental tests Power distribution ConclusionModel validation
Ag. Tractor Standards
Guarantee
State of The Art Architectures
Load Sensing
Competitive Machine
Operation
Optimal BehaviorAll working maneuvers?
How to know?
4
Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
Research goal
We know: Different sources of power loss existing [load sensing]
• Feasible and cost-effective solutions for significant increase of energy efficiency of such system to improve overall system efficiency.
Introduction Model development Experimental tests Power distribution CurrentModel validation
5
Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
Research approach
5
Classification of Energy Losses
Solution Proposal
Experimental Characterization
Validated AMESim Model
Machine Instrumentation
Steady State Testing
Dynamic Testing(Real Drive Cycles)
Introduction Model development Experimental tests Power distribution CurrentModel validation
6
Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
Steady State Testing
Dynamic Testing(Real Drive Cycles)
Experimental Characterization
Validated AMESim Model Testing
Solution ProposalImproved? Yes!
No
Improved?
Deliver
Yes!
No
Research approachIntroduction Model development Experimental tests Power distribution CurrentModel validation
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
Reference hydraulic circuit
Variable Displacement Load Sensing Pump
Hitch Control Valve
EHR Control Valve 1 EHR Control Valve 2
Introduction Model development Experimental tests Power distribution CurrentModel validation
8
Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
pump supply port LS signal port
CH
CH CH
System modelingVariable Displacement Load Sensing Pump
CHCH CH
CH
CH
CH
CH
CH CH
CH
Tank
Flow Compensator
Pressure Compensator
Control Piston
pump drain portlow pressure circuit port
shaft speed
Introduction Model development Experimental tests Power distribution CurrentModel validation
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
Pressure Compensator
System modeling
CH
CH CH
friction
𝐹
friction
𝐹𝑠
overlap underlap
𝑄 = 𝑐𝑞 ∙ 𝐴 ∙2 ∆𝑝
𝜌∙ 𝑠𝑖𝑔𝑛 ∆𝑝
CH𝑑𝑝
𝑑𝑡=
𝐵 𝑝 ∙ 𝑄 𝑝
𝑉 𝑝
Orifice equation:
Internal volumes:
overlapunderlap Jet forces:
𝐾 = 𝑘𝑗𝑒𝑡 ∙1
2tanh
2 𝑙𝑎𝑝 − 𝑚𝑖𝑛
𝑚𝑖𝑛+ 1
𝐹𝑗𝑒𝑡 = 𝐾 ∙ 2 ∙ 𝑐𝑞 ∙ 𝐴 ∙ ∆𝑝 ∙ 𝑐𝑜𝑠𝜃
Spool equilibrium: 𝐹 = 𝐹𝑠 + 𝐹𝑗𝑒𝑡
friction
𝑭𝒔
Viscous friction force: 𝑓 = −𝑏 ∙ 𝑣
Introduction Model development Experimental tests Power distribution CurrentModel validation
10
Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
• Pressure-flow compensator dynamic test: SAE STANDARD J745 JUN2009
Load Pressure:Model = 158.77 bar
Experiment = 159.11 bar
Standby Pressure:13.43 bar11.50 bar
Model validationIntroduction Model development Experimental tests Power distribution CurrentModel validation
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
Experimental tests set upIntroduction Model development Experimental tests Power distribution CurrentModel validation
Reference Vehicle
Hydraulic Theory
MAHA Fluid Power
Research Center
EHR Valves
MAHA Test Plan
DLG PowerMix Test
Nebraska Test
Agricultural Tractor
Testing Standards
Realistic Steady and Dynamic Tests
EHR Test Summary
Number of Tests
Single Remote 224
Multiple Remotes 48
TOTAL 272
• Maha Test plan:
– Based on real tractor testingstandards.
– Contains specific modifications forenergy consumption analysis
– Versatile & easily adjustable to largeror smaller size tractors.
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
Experimental tests set up
CE GB
FC
PC
A B
TP
LS
R E
A B
TP
LS
R E
𝒔
𝒔
𝒔 𝒔 C C
C
Introduction Model development Experimental tests Power distribution CurrentModel validation
𝐹𝑙𝑜𝑤𝑚𝑒𝑡𝑒𝑟
𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑇𝑟𝑎𝑛𝑠𝑑𝑢𝑐𝑒𝑟
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
System Model Tests
EHRHitch control valve
100% Flow CommandEHR: (Retraction/Extension, High/Low 𝑇𝑜𝑖𝑙)
HITCH: (Rising, High/Low 𝑇𝑜𝑖𝑙)
0% Load50% Load
75%Load
90% Load
90% LoadEHR: (Retraction/Extension, High/Low 𝑇𝑜𝑖𝑙)
HITCH: (Rising, High/Low 𝑇𝑜𝑖𝑙)
25% Flow command
50% Flow Command
75% Flow Command
LS pump
Load setting
Test Plan for EHR and Hitch
Introduction Model development Experimental tests Power distribution CurrentModel validation
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
System model validation results
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 20 40 60 80 100
Flo
w R
ate
Pre
ssu
re
Load setting [%]
• Different load settings• Full command• Retraction• High 𝑇𝑜𝑖𝑙
• High RPM
Single Remote Test Results Comparison
Introduction Model development Experimental tests Power distribution CurrentModel validation
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
System model validation results
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
40 50 60 70 80 90 100
Flo
w r
ate
Pre
ssu
re
Remote load setting [%]
Hitch with Single Remote Test Results Comparison
• Different load settings on remote• Hitch cylinder raising• Full command• Extension• High 𝑇𝑜𝑖𝑙
• High RPM
Introduction Model development Experimental tests Power distribution CurrentModel validation
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
System power distribution
Power Distribution Comparison Between Different Loads for Single Remote Test
Full command, Retraction, High RPM, High oil temperature
Power Distribution Comparison Between Different Loads for Dual Remotes Test
Full command, Retraction, High RPM, High oil temperature
52.64
55.99
9.42
20.33
5.56
4.37
8.25
2.99
8.74
2.11
15.40
14.21
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
75%
90%
Power distribution in the system [%]
Load
Set
tin
g [%
]
Useful power on remote TF pump
EHR local compensator EHR main spool
EHR lock check valve Back pressure and quick coupling
52.64
55.99
9.42
20.33
5.56
4.37
8.25
2.99
8.74
2.11
15.40
14.21
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
75%
90%
Power distribution in the system [%]
Load
Set
tin
g [%
]
Useful power on remote TF pump
EHR local compensator EHR main spool
EHR lock check valve Back pressure and quick coupling
29.07
13.13
0.31
11.06
4.337.19
0.75 0.61
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
75% Load 50% Load
EHR lock check valve EHR main spool
EHR local compensator Useful power on remote
Introduction Model development Experimental tests Power distribution CurrentModel validation
EHR A EHR B
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
Introduction Model development Experimental tests Power distribution CurrentModel validation
𝐸𝐻𝑅1𝑐𝑚𝑑 𝐸𝐻𝑅2𝑐𝑚𝑑 𝑄𝑝𝑢𝑚𝑝 𝑄𝐸𝐻𝑅1 𝑄𝐸𝐻𝑅2
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Analysis of Power Distribution in a Mid-Size Agricultural Tractor through Modeling
ConclusionIntroduction Model development Experimental tests Power distribution CurrentModel validation
Rationale & Motivation
Model Development
&Validation
Experimental Instrumentation
& Testing
Complete Characterization
&Technological Improvements
Thank youfor your attention!
June 5th, 2019MAHA Fluid Power Research Center
Xin Tian, Josias Cruz [Presenter]
Advisor: Andrea Vacca