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Simcenter Anovis is a system primarily used for end-of-line testing of rotating machinery. It automatically spots and identifies component and assembly anomalies using innovative Noise, Vibration, and Harshness (NVH) metrics.
End-of-line testing is a process integrated into the production phase, used to test if full vehicle or assemblies function as intended. Items being tested are subjected to a set of predetermined evaluations to make pass/fail decisions. The video below shows the end-of-line testing of an engine.
Video: Engine Testing
Simcenter Anovis (Acoustic Noise and Vibration Signal Analyzer) automatically identifies faults during the production of internal combustion engines, transmission systems and electric motors.
This article covers the following:
- Anovis system overview
- Anovis hardware
- Anovis software
- Reference material
1. Simcenter Anovis System Overview
The Simcenter Anovis system (Figure 1) consists of a series of hardware and software components:
- Anovis hardware (sometimes referred to as Signal Recording Device)
- Anovis software
- signal processing software (Anovis Signal Processing)
- visualization and configuration software (Anovis Signal Analyzer)
- Sensors (Microphone, accelerometer and laser vibrometer)
- Several interface modules for test bench interaction
Figure 1: Simcenter Anovis System Structure
Simcenter Anovis acts as a slave of the test bench system, being one of the many items in the test bench software, thanks to its easy integration with the test benches.
2. Simcenter Anovis Hardware
The Anovis hardware (Figure 2) records a variety of sensors over large bandwidths, including vibration with either accelerometers or laser vibrometers, sound, rotational speed, temperature and torque.
Figure 2: Simcenter Anovis hardware: compact DIN rail mountable version and 19-inch rack-mountable unit
It supports ICP sensors by supplying power to each channel. The channel count is scalable, and it is available in a 19-inch rack-mountable unit or as a compact DIN rail mountable version. The hardware can be seamlessly integrated with Simcenter Anovis software.
3. Simcenter Anovis Software
The Anovis software contains many objective sound and vibration metrics that help detect certain faults.
Anovis Signal Processing provides the signal-processing functions. It normally requires no user interaction except sensor calibration or testing of self-installed setups.
Figure 3: Simcenter Anovis Signal Analyzer Software
The Simcenter Anovis Analyzer establishes the user interface to the Anovis system. Visualization and analysis of the data are made with Anovis Analyzer. It is also used for the creation of test setups.
Simcenter Anovis Analyzer and Signal Processing are used in every application and are the standard elements of the Anovis system.
End-of-line testing with NVH metrics is different from the classical NVH testing used in product development, as once the system is set up in the production line, there is hardly ever any interaction with the hardware and the software.
During the deployment, NVH-based metrics that detect the possible defects are set up as features in the Simcenter Anovis software. It checks every item in the test bench according to these metrics and makes pass/fail decisions. If there is a suspicious item, it is sorted out to be sent to the inspection area.
But what about unknown defects?
Suppose that the engine producer makes a modification on this engine by changing a component. He or she also builds a new fault. How can this be detected with Simcenter Anovis?
Simcenter Anovis provides a powerful tool called Chameleon, which can detect this certain kind of previously unknown fault. The main advantage is that it uses non-labelled data from the current production for adaptation.
Figure 4: Like a chameleon, the Simcenter Anovis software adapts automatically to find new faults
Assuming that most of the engines are fault-free, Chameleon creates a tolerance scheme based on statistics and rejects deviating measurements. This helps sort out the items with this new kind of fault for further inspection—it is up to the quality engineer to detect if it is a quality-related issue or not. If it is, a new metric can be built using offline analysis based on this measured data.
To be able work the best under different conditions, a variety of transducers can be used with Simcenter Anovis.
- Microphone: when defect leads to little vibration but a lot of noise, such as belt drives
- Probe-tipped Anovis accelerometer: if feedback of mass is non-critical, e.g. engines or transmissions
- Laser vibrometer: when a microphone or a probe tip cannot be installed due to space limitations and feedback of the mass is critical, such as engines with many aggregates or cables
- Accelerometers: fixed to the test bench to monitor its most critical components, being bearings and shafts
6. Applications of end-of-line testing of rotating machinery
Many different types of rotating systems can be tested, including transmissions, combustion engines, and electric motors.
6.1 Internal combustion engines
Pass/fail decisions can be made during cold tests and hot tests both on diesel and petrol engines (Figure 5).Examples of fault identification of a Internal Combustion Engine (ICE) include:
- Cam Shaft: surface defects, chatter marks
- Valve train: rattling, too big clearance, defective HVA, wrong mounted cam follower / cam leaver, defective cam follower
- Membrane pump, high pressure pump: missing tappet, drive issues, bearing faults
- Oil pump: tooth defects, faulty pressure control, oil pipe blocked
- Turbo charger: damages, geometry faults
- Timing drive: chain noises (howling rattling), chain tensioner defective, wrong mounted chain guide, chain wheel damage, not aligned chain wheels
- Tooth gear drives: tooth damage, surface defects, wrong tooth flank geometry, wrong clearance
- Balancer shaft: not synchronized, drive noises
- Vacuum pump: surface defects, chatter marks
- Piston, crank shaft: relaxation oscillation, conn rod clearance, particles
Figure 5: Engines in a line for quality inspection
6.2 Transmission systems
Examples of fault identification of automatic, CVT and manual transmission systems include:
- Gear issues: gear noises from spur gear and bevel gear sets, gear defects, ghost orders (machine orders)
- Bearing issues: bearing noises and damages
- Other issues: noise from oil pumps, shifting noises, load change noises, unbalances and turn angle analysis
6.3 Electric Drives
Simcenter Anovis also identifies anomalies of modules with motorized drive mechanisms such as seat motors, window lift motors, door lock motors, electric steering motors, AC actuator motors, wiper motors and white goods.Examples of defects are:
- Bearing noises, bearing defects
- Rotor vibrations
- Eccentricity, tumbling of rotor
- Magnet pairing
- Gear teeth defects such as gear meshing and damaged gear teeth