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 (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 data acquisition hardware.
Some key features of the SCADAS RS system are:
Wide range of signal conditioning including strain, ICP, digital buses, pulse counters, string pots, load cells, and more…
Operation in a wide range of temperatures, humidity, and vibration levels
Remote login (via Wi-fi, Cellular, …) for test setup, data viewing, and data retrieval
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 Software and Connectivity 2.4.1 Simcenter SCADAS RS Recorder App 2.4.2 Simcenter Testlab Neo 3. Simcenter SCADAS RS Hardware Units 3.1 Recorder Unit 3.2 Uninterruptable Power Supply Unit 3.3 Conditioning Units 4. SCADAS Mobile/Recorder and SCADAS RS 5. Conclusions
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.
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 and power 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 Software and 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 Neo 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 from any device with a web browser 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 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 (Figure 11), and diagnosing errors from the office while tests are run on distant locations.
Figure 11: The internal Simcenter SCADAS RS Recorder App can be accessed from the web browser on any remote device without installing any software.
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.
The Simcenter SCADAS RS hardware can also be setup and measured using a ethernet connection over a PC with Simcenter Testlab Neo software (Figure 12).
Figure 12: Simcenter Testlab Neo PC-based software with direct ethernet interface to Simcenter SCADAS RS hardware.
With the Simcenter Testlab Neo software, 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.
The Simcenter Testlab Neo software also has helpful setup features like an Microsoft Excel "like" channel interface for channel setup. Copy/paste can be done between channels and to/from Excel.
Simcenter SCADAS RS consists of “units”. Units can be different types: recorder, power, conditioning.
3.1 Recorder Unit
The recorder unit is the "brains" of the SCADAS RS. 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 13.
Figure 13: 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. The recorder has an internal 240 Gb solid state drive.
The table below provides an overview of the most important specifications of the Simcenter SCADAS RS REC unit is shown in Table 1:
Table 1: Specification for the Simcenter SCADAS RS recorder.
The recorder unit also hosts built-in software that can be accessed from any browser via the recorder Wi-fi connection. More information in the knowledge article: Simcenter SCADAS RS Recorder App.
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. See Figure 14.
Figure 14: Simcenter SCADAS RS Uninterruptable Power Supply Unit.
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).
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 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 also include built-in signal conditioning.
Available conditioning units:
B24: Twenty four channels of bridge conditioning for strain gauges, potentiometers, piezoresistive sensors, inductive and RTD sensors
S24: Twenty four channel ICP and Voltage conditioning unit for accelerometer sensors, force cells, torque cells and current loop sensor
U12: A 12-channel universal unit combines all conditioning types (strain, ICP, etc) with 8 kHz bandwidth
U12E: A 12-channel universal unit combines all conditioning types (strain, ICP, etc) with 20 kHz bandwidth
DI: Digital pulse (9 inputs) and CAN bus unit (4 CAN bus)
ECAT: Outputs up to 96 channels (from B24, S24, ...) to Ethercat
Conditioning units are shown in Figures 15 through 20:
Figure 15: Simcenter SCADAS RS B24 Bridge Conditioning Unit.
Figure 16: Simcenter SCADAS RS S24 Sensor Conditioning Unit.
Figure 17: Simcenter SCADAS RS U12 Universal Conditioning Unit.
Figure 18: Simcenter SCADAS RS DI Digital Pulse and CAN bus Unit.
Figure 19: Simcenter SCADAS RS ECAT Ethercat Unit.
Figure 20: Simcenter SCADAS RS TC20 Thermocouple Unit.
Table 2 below provides key specifications of the U12, S24, and B24 conditioning units:
Table 2: Specifications of select 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.
4. SCADAS Mobile/Recorder and SCADAS RS
How does the SCADAS RS compare to SCADAS Mobile/Recorder? The main differences are summarized in Table 3 below:
Table 3: Comparison of SCADAS Mobile/Recorder to SCADAS RS.
One key difference between the SCADAS Mobile/Recorder line and the SCADAS RS, is that the SCADAS RS has measurement setup and viewing software embedded in the hardware. This embedded application can be accessed by any device with a web browser to monitor the test in progress, change the channel setup, and more. No software installation or licenses are needed to run the embedded Recorder app.
5. Conclusions
Simcenter SCADAS RS highlights include:
Multi-user simultaneous access for faster test campaigns
Operation in a wide range of temperatures, humidity, and vibration levels
Flexible mounting
Remote login (via Wi-fi, Cellular,…) for test setup, data viewing, and data retrieval
Wide range of signal conditioning including strain, ICP, digital buses, pulse counters, string pots, load cells, and more…
Modular design with fail safe back up of data and channel configuration