Servohydraulic Testing Technology
(SHT 501)
Why do we Test?
The processes used for ground vehicle product development, and the decision paths that are followed to choose the most appropriate test.
Virtual Prototyping
How the test-lab can support virtual modeling with the right information at the right time. A comprehensive look at the current methods of component characterization
Reproducing Failures
What the various failure modes are, and how we reproduce them. Fatigue theory provides grounding for the concepts to be discussed later.
Anatomy of a Servo Hydraulic System
Principles of operation of each component in a Servohydraulic test system, different types, attributes, and how they are sized.
Rig Design Techniques
The pitfalls of test rig design. How to meet the competing needs of linear, high stiffness, low moving mass systems through the use of materials, bearings, bolted connections, weldments, castings and so on. The design of bell-cranks, seismic masses, and environmental chambers is also covered here.
Durability Test System
s The various components and systems used for durability testing, from bedplates to engine simulation to complete 25-channel road simulation. The methods used, test design considerations, and how the tests are integrated into product development.
Anatomy of a Control System
Proportional-Integral-Differential-Feedforward (PIDF) control design and principles of operation, along with the various loop stabilization techniques. Three-mode control for the accurate control of acceleration, velocity and displacement. Calculated variable (matrix) control for simplifying multi-channel systems. All the various optimization methods in use today, including Adaptive Control and the principles behind its operation.
Programming Techniques and Applications
Function generation, block programming, histogramming, peak-valley slicing, random vibration control and time history simulation techniques and their applications in different types of testing. Squeak and Rattle, Ride Comfort and Highly Accelerated Life Testing are also covered.
Basic Vibration Theory
Some basic mathematics and a solid intuitive feel for dynamic systems, Fourier transforms and Autosepctra provide grounding for the concepts to be discussed next. If the student blanks out during the math all is not lost, it's designed to be optional (and minimal).
Iterative Simulation
How transducers are selected, how the data is collected, and how the data is analyzed and prepared for simulation. Measuring, analyzing and inverting the Frequency Response Function. Non-linearities, singularities and the iteration process. New methods of iteration are also covered, including Singular Value Decomposition and FRF iteration.
Running the Test
Generic road profiles and test monitoring techniques. Finally, test reporting and data archival.
