Download - Supporting Document Appendix_01
PhD project: Modelling, Testing and Analysis of a Regenerative Hydraulic Shock Absorber
System
Abstract: Recoverable energy in vehicle suspension systems has attracted intensive attention in
recent years for improved performances. Various design concepts and structures of regenerative
suspensions have been presented and investigated to recover the energy of linear motion and
vibration between the vehicle body and wheels which is from irregular road surfaces. Unfortunately,
the usability of the regenerative technologies in operating vehicle suspension systems is still
insufficient for providing detailed techniques to be productised to unleash its market potential.
To advance the technologies, a regenerative hydraulic shock absorber is investigated rigorously by
examining the system at various developing stages including fabricating a prototype of a commonly
used shock absorber, modelling all hydraulic, mechanical, electromagnetic processes, simulating its
behaviours, testing its desirable performance and evaluating its on-road usability, which has
resulted in a number of new understandings that brings forward considerable advancements on the
technologies improvements.
Based on the configuration of the prototype a comprehensive mathematical model is developed for
the regenerative hydraulic shock absorber system. The various losses and nonlinearity have been
taken into account in modelling hydraulic, mechanical, electromagnetic processes, which allows
more detailed influences and agreeable predictions with the experimental works to be obtained. The
introduction of the gas-charged hydraulic accumulator into the system been explored in both
modelling and testing to realise the smoothing effect in this work, and shown to be a useful means
by which the hydraulic behaviour and recoverable power can be improved with desirable damping
performance and acceptable recoverable power.
Model parameter identifications and refinements based on the online data are systemically
investigated. It has found that the pressures, rotation speeds and electrical outputs, which are readily
available in the system, are sufficient to determine and refine uncertain model parameters such as
the voltage constant coefficient, torque constant coefficient, generator internal resistance and
rotational friction torque using a common least square method.
The original experimental rig and measurement systems for the study of regenerative hydraulic
shock absorber are designed and built. The variations in motor pressure and shaft speed under
different excitations, and also voltage output and recoverable power at different electrical loads.
Additionally, the experimental works are not only used to validate the predicted results
comprehensively, but also to offer a practical evaluation method for the system at various operating
conditions. Additionally, control strategies and their realisation on a general propose PC computer
are developed based on constant voltage, current and resistance schemes to carry out the
investigation of the system performances, which allows it to be fully evaluated upon the
compromise between the damping behaviour and power regeneration performance for different road
conditions.
Furthermore, the simulation of the entire system and parameter computations are all realised on the
Matlab platform, which provides sufficient flexibility to take into account more influence factors for
accurate and detailed analysis and thus can be the effective mathematical tools for further
development researches in the directions such as the optimisation of the structures, control
strategies and system integrations.
Solidworks
Experimental rig design (Suspension/shock absorber system):
Details of Bearing housing design and assembly:
PARTS LIST DETAIL DESIGN OF BEARING HOUSING
Part
No. Quantity Description Remarks
B1 1 HOUSING
B2 1 OUTER BEARING FLANGE:DIA240 x
32 THK
B3 1 INNER BEARING FLANGE:DIA 240 x
32 THK
B4 1 MAIN SHAFT:80 DIA x 525 LG
B5 1 SPACER
B6 1 INNER BEARING:
DUAL ROW SPHERICAL ROLLER
ID 65, OD 140, W 48
SKF REF:22313E SKF 22313E
B7 1 OUTER BEARING:
DUAL ROW SPHERICAL ROLLER
ID 70, OD 150, W 51
SKF REF: 22314E SKF 22314E
B8 2 LIP SEAL C/W DUST LIP
ID 55, OD 75 W 8
SIMRITS BAUMSLX7: 55-75-8 BAUMSLX7:55-75-
8
PARTS LIST SADDLE ASSEMBLY
MATERIAL:SIMRIT 75KM 585
B9 2 O’RING
ID 160x3 CROSS SECTION O-ring 160-3
MATERIAL: SIMRIT 83FKM 592
B10 1 RETAINING PLATE: 460 x 80 x 25 BH 012
B12 1 LOCK NUT
1 M60 x 2 SKF KM12
B13 1 LOCKING WASHER M60 SKF MB12
B14 16 M12 x 40 LG, HEX HEAD M/C SCREW
B15 16 M12 SPRING WASHER
B16 2 M20 x 70 LG HEX HEAD M/C SCREW
B17 2 M20 SPRING WASHER
B18 2 M10 GREASE NIPPLE
B19 1 BED
B20 1 SADDLE ASSEMBLY
B21 1 KEY
Part
No. Quantity Description Remarks
S1 1 SADDLE TOP PART
S2 1 SADDLE RIGHT SUPPORT PART
S3 1 SADDLE LEFT SUPPORT PART
S4 14 M8 SPRING WASHER
S5 14 M8 x 40 LG, HEX HEAD M/C SCREW
S6 2 M20 x 38 LG, HEX HEAD M/C SCREW
S7 2 M20 SPRING WASHER
Simulink
Half car model (tractions, torques and various inputs)
All files available upon request, two examples have been show in the following.
Data acquisition process
Designing and creating an engineering application with Lab-Windows/CVI starts with the user
interface, and an intuitive creation of graphical user interface (GUI) designer is built. The Lab-
Windows/CVI offers several key features, such as advanced debugging, automatic code generation,
data management and integrated source code control.