Simcenter SCADAS RS for Testing in Harsh Environments
Machines and vehicles need to be designed to withstand loading during operation. It is critical to avoid unintended failures. To do so, loads and forces must be acquired during actual operation, which can take place in demanding environments with high vibrations, limited access, and wet conditions..
The Simcenter™ SCADAS™ RS hardware (Figure 1) is a system engineered for performing load data measurements in hostile environments. It is used to measure and understand load cycles of operating equipment as part of their life cycle design.
Figure 1: Simcenter SCADAS RS Hardware
Some key features of the SCADAS RS system are:
This article covers the following:
1. Load Data Acquisition Challenges and Background
2. SCADAS RS Design
2.1 Temperature, Vibration, Ingress Protection (IP)
2.2 Flexible Mounting
2.3 Modular Design
2.4 Connectivity
3. Measuring with Simcenter SCADAS RS
3.1 Conditioning Units
3.2 Uninterruptable Power Supply Unit
3.3 Recorder Unit
3.4 Digital Input Unit
4. Simcenter SCADAS RS Applications
1. Load Data Acquisition Challenges and Background
Load data acquisition is the process of collecting representative loads that are expected to occur during the life cycle of a machine, vehicle, or object. Loads may result in failure, fatigue, excessive vibration, discomfort, or other phenomena that lead to undesired results e.g. outage, repairs, driver fatigue etc.
Loads are collected from representative tests on a prototype. This means tests are done on proving grounds, public roads, or even at customer locations. The steps involved in performing a typical load data acquisition campaign are shown below in Figure 2.
Figure 2: Typical load data acquisition campaigns start with test planning (left), test setup and measurement (middle), and ends with analysis and next steps (right).
For representative load data acquisition, measurements need to be done in the same conditions as in real life. For off-highway machines, agricultural equipment, mining equipment, trucks, buses, and automobiles, these test conditions can get quite tough. Test campaigns may run in polar regions, as well as in desert areas, or in any weather condition including rain and snow with machines loaded to their extremes as shown in Figure 3.
Figure 3: Load data acquisition takes place far from an office setting.
Measurements are often performed at locations where customers experience a specific load problem. In such situations, load measurements are run far from the office. They are often remote areas with difficult to reach back-office services in case assistance is needed.
Load data acquisition tests involve a multitude of sensors measured simultaneously at different sample rates. Typical sensors include (but are not limited to): strain gauges (full, half and quarter bridges), accelerometers, string pots, force cells, torque cells, pressure sensors, temperature sensors (typically thermocouples of type K, J and T or RTD sensors type PT100, PT200 and PT1000), LVDT’s, current transmitters, tachometer or digital pulse signals, but also straight voltage signals. Next to this, signals from digital CAN or XCP buses need also be included in the acquisition data stream.
Test conditions require intelligent interaction of the acquisition system with the conditions that the prototype is subject. In a manual mode, the operator may start or stop tests with a button push. But more and more tests are executed in difficult conditions, or with less skilled personnel, or no personnel interacting with the test system, or even no personnel present at all (e.g. autonomously driving vehicles). In those cases, on-board intelligence is required for the data acquisition system to acquire the exact data that corresponds to the load case under test. The ability to collect relevant data, with or without user interaction, even from engine start, is a crucial requirement of a modern data acquisition system.
These challenges are summarized in Figure 4.
Figure 4: Summary of challenges faced when performing a load data acquisition measurement campaign.
Load data acquisition test teams are also challenged to perform more tests with less people in shorter time. Test systems must be flexible, and easily adaptable for large and small test prototypes alike.
2. SCADAS RS Design
The design of the SCADAS RS was undertaken with the previously explained challenges in mind (Figure 5).
Figure 5: SCADAS RS and its design goals
The specifics are addressed in the following sections.
2.1 Temperature, Vibration, and Ingress Protection (IP)
The Simcenter SCADAS RS is tested to withstand high loads (10gRMS, 100g shock) and is protected for water and dust according to IP66/67 ingress protection. Simcenter SCADAS RS conditioning, power, and digital input units can be used under temperature conditions ranging from -40°C (-40F) up to +65°C (+150F).
A summary is shown in Figure 6.
Figure 6: Summary of SCADAS RS Environmental Specifications.
The recorder conditioning unit maximum operational temperature is +55°C, which can be extended if providing enough airflow. Besides environmental concerns, equipment needs to be mounted in limited access areas, which is discussed next section.
2.2 Flexible Mounting Next to this, Simcenter SCADAS RS has flexible mounting. Units can be stacked on top of each other with a built-in slide and latch mechanism (no tools required). Units can then be fixed using strap belts to the machine or vehicle, either stacked vertically or mounted on their back as shown in Figure 7.
Figure 7: SCADAS RS can be strapped vertically (left) or horizontally (right) for testing
Mounting holes are available for firmly mounting units on a prototype.
A single daisy chain cable runs from one unit to the other and distributes power and data as shown in Figure 8.
Figure 8: Daisy chaining is done with a single cable between units.
These cables are available in different lengths from less than 1m to 50m; this way Simcenter SCADAS RS units can be combined or distributed over the entire machine or vehicle.
2.3 Modular Design
A Simcenter SCADAS RS system has a modular design. Individual conditioning units are connected with a daisy chain cable for data and power. Up to four daisy chains of conditioning units connect to a single Simcenter SCADAS RS recorder unit (REC) unit where data is centrally, safely and securely stored (or streamed to a PC running Simcenter Testlab).
The Simcenter SCADAS RS recorder unit contains a processor for intelligent on-board analysis of the data to ensure that all relevant load data acquisition data is correctly captured.
See Figure 9 below for a schematic of modular layout of multi-channel SCADAS RS:
Figure 9: Layout of a 100+ channel SCADAS RS system with recorder and laptop.
Daisy chains of conditioning units are powered by Simcenter SCADAS RS uninterruptable power supply (UPS) units. When more units are used, more power is needed and provided by simply adding UPS units to the daisy chains.
Settings are stored on each unit. When a unit is moved from one location to another, all parameters can simply be read out again.
During instrumentation, multiple people can work on prototype instrumentation simultaneously. Parallel instrumentation allows a subcontractor to instrument a part of the full prototype. Upon assembly of the sub-component with the full prototype, the Simcenter SCADAS RS units can simply be hooked up to the rest of the data acquisition settings, and settings are read out by a simple button click.
2.4 Connectivity
Finally, Simcenter SCADAS RS has multiple connectivity options. It can be accessed over UTP, USB, Wi-Fi or even using external modems. It interfaces seamlessly with Simcenter Testlab for acquisition and processing.
The SCADAS RS hardware has a built-in web-based interface. With the on-board applications any Simcenter SCADAS RS unit can be wirelessly accessed without an external tool as shown in Figure 10.
Figure 10: Data being acquired on a SCADAS RS can be seen by a web browser from any device. Test setup, measurement start/stop, and post viewing of data can be done as well.
A simple web browser is enough to provide access to the on-board app installed on every Simcenter SCADAS RS unit. Even more, multiple users can access a Simcenter SCADAS RS system at the same time.
Given its multiple connectivity options, it is even possible to access the system remotely, and diagnosing errors from the office while tests are run on distant locations. Data can be acquired using intelligent triggers and is stored securely on-board. Each test recording can be uploaded manually or automatically to a (company or commercial cloud) server after the measurement for further analysis and automated processing.
3. Measuring with Simcenter SCADAS RS
Test preparation can start from a virtual frontend, a so-called ‘digital twin’ of the final physical hardware that will be used during physical tests. Once the physical hardware is available, all virtual preparation can be downloaded immediately, avoiding any duplicate work and errors when building up the data acquisition system.
To prevent further errors, channel settings can be taken over from company sensor databases with automated lookup based on e.g. sensor serial numbers. Sensor settings can easily be copied across similar conditioned sensor types.
Simcenter SCADAS RS consists of “units”. Units can be one of four different types: conditioning, recorder, power, and digital inputs.
3.1 Conditioning Units
Conditioning units connect to analog sensors, provide them with power and convert analog sensor signals to digital data.
SCADAS RS conditioning units come with a universal connector for plugging in a transducer. This allows different types of sensors to be powered and measured via a single standardized connector. Simcenter SCADAS RS units have built-in signal conditioning.
There are three types of conditioning units:
Conditioning units are shown in Figures 11 through 13:
Figure 11: Simcenter SCADAS RS B24 Bridge Conditioning Unit
Figure 12: Simcenter SCADAS RS S24 Sensor Conditioning Unit
Figure 13: Simcenter SCADAS RS U12 Universal Conditioning Unit
The table below provides an overview of the most important specifications of the different conditioning units:
Table 1: Specifications of Simcenter SCADAS RS conditioning units
Settings are stored on the unit. When a unit is moved from one location to another, all parameters can simply be read out again.
3.2 Uninterruptable Power Supply Unit
Stable power for Simcenter SCADAS RS system is provided from an uninterruptable power supply (UPS) unit that supports supply voltages from 9 to 54 VDC from unregulated sources. This is even done during prolonged cranking, or from two external hot-swappable batteries. One UPS unit can power a few other units depending on their power needs.
Simcenter SCADAS RS units are powered by pressing a power button. Or they can be activated from a remote on/off signal (e.g. an engine key-switch activation).
Figure 14: Simcenter SCADAS RS Uninterruptable Power Supply Unit
When more power is needed, UPS units can simply be added to the configuration. In case of permanent power outage, safe shutdown mechanisms protect any data measured to make sure no critical information gets lost.
3.3 Recorder Unit
These conditioning units can be daisy-chained to a central recorder unit (REC) that combines all sensor data streams with digital inputs from up to three quadrature encoders, four CAN buses, GNSS/GPS signals etc. and streams it to a local SSD hard disc for storage. See Figure 15.
Figure 15: Simcenter SCADAS RS Recorder Unit
The recorder unit can further be configured for intelligent data capturing using advanced triggers and online calculated channels from analog sensor data.
3.4 Digital Input Unit Separately, a Simcenter SCADAS RS digital input (DI) unit is available that supports eight encoders and four CAN buses. See Figure 16.
Figure 16: Simcenter SCADAS RS Digital Input Unit
The table below provides an overview of the most important specifications of the Simcenter SCADAS RS REC and DI units are shown in Table 2:
Table 2: Specification for the Simcenter SCADAS RS recorder and digital input units
4. Conclusions
Simcenter SCADAS RS can significantly improve operational processes and efficiency of test teams.
Simcenter SCADAS and other Acquisition Hardware
Questions? Email ismail@dagtech.com.my
