EMrex in San Antonio!

15/10/2018

We were unable to follow the events in this year’s Emerson User Group Meeting in San Antonio, Texas USA. There were lots of tweets which may be viewed under the Hastag #EMrex. However we did get a number of releases which we have published and present them here as a group.

Mike Train hands over to Lal Karsanbhai

Mike Train used the occasion to  announce his replacement as Executive President of Emerson Process Automation, Lal Karsanbhai, while Mike Train is to assume the role of President at Emerson!

The Emerson Exchange 365 Community is a useful group for Emerson users to keep up with developments and applications.

• Dependable & responsive delivery! (5 Oct 2018)

• Connection to take the next step in digital transformation. (5 Oct 2018)

Where are you? (4 Oct 2018)

• Scalable Digital Twin to Bridge Plant Design. (4 Oct 2018)

• PLC technology company to be acquired. (4 Oct 2018)

• Acquisition strengthens service to descrete markets! (3 Oct 2018)
      Irish company acquired – HTE Engineering Services Ltd.

• Helping customers seize €22 billion ($25b) savings! (3 Oct 2018)

Roadmap towards Digital Transformation. (2 Oct 2018)

• Programme fast-tracks digital transformation. (1Oct 2018)

The next Emerson User Group Americas is scheduled for Nashville (TN USA) next September 23-27 2019. Always a good show!


Power needs for autonomous robots!

20/08/2018
Jonathan Wilkins, marketing director at EU Automation, argues that the way we power six axis robots needs to be reassessed to meet the needs of new applications such as autonomous mobile robots (AMRs).

Since industrial six-axis robots were popularised back in the 1960s, the technology that makes up robots, as well as the way in which we now use robots, has changed considerably.

What was once considered a high-risk sector, where robots were relegated to operating in cells and cages behind no-go zones, has changed to one where robots can now work in collaboration with human workers.

Advances in motor technology, actuation, gearing, proximity sensing and artificial intelligence has resulted in the advent of various robots, such as CoBots, that are portable enough to be desktop mounted, as well as autonomous mobile robots (AMRs) that can move freely around a facility.

These systems are not only capable of delivering high payloads weighing hundreds of kilograms, but are also sensitive enough to sense the presence of a human being at distances ranging from a few millimetres to a few metres. The robot can then respond in under a millisecond to stimuli, such as a person reaching out to guide the robot’s hand, and automatically change its power and force-limiting system to respond accordingly.

Although six-axis robots and CoBots are predominantly mains powered, portable AMR service robots are gaining popularity in sectors as diverse as industrial manufacturing, warehousing, healthcare and even hotels. In these settings, they can operate 24/7, only taking themselves out of action for charging and taken offline by an engineer for essential repairs and maintenance.

In the warehousing sector, for example, the picking and packing process can be manually intensive, with operators walking up and down long aisles picking products from a shelf to fulfil each order. This is a time consuming and inefficient process that adds time to the customer order. Using an autonomous mobile robot in this situation can allow the compact robot to pick up the shelf and move it to the human operator in true “goods-to-man” style.

However, this demanding use-cycle prompts the question: are the batteries that power these robots sufficiently suited to this new environment? To answer this, we need to understand the types of batteries used.

The two most popular types of secondary, rechargeable, battery are sealed lead acid (SLA) and lithium-ion (li-ion). Having been around for nearly 160 years, lead acid technology is capable of delivering high surge currents due to its low impedance. However, this type of battery can be large and heavy, making it impractical for smaller machines.

Alternatively, lithium-ion provides the highest density and delivers the highest energy-to-weight ratio of any battery chemistry, which allows design engineers to use it in even the most compact devices. It also maintains a stable voltage throughout its discharge cycle, resulting in highly efficient, long runtimes.

When choosing robotic systems for their application, it’s important that engineers match the right type of battery to the load. As we increasingly begin to rely on smart factories with high levels of portable and mobile automation, considering the power needs of each device will be vital in delivering long run times with high efficiency.

@euautomation #PAuto #Robotics

Power take-off torque monitoring.

07/08/2018
AIM – Precisely & Quickly Monitor Power Take-Off Torque on A Wave Energy Converter

Challenge
As part of a project funded by Wave Energy Scotland, 4c Engineering needed to test various configurations of the SeaPower Platform, a Wave Energy Converter (WEC), to determine the effects on power capture.   To do this they needed a reliable and accurate way of measuring power take-off (PTO) torque, forces, positions and pressures of the waves on the SeaPower Platform.

Why? Establishing the most efficient design with the highest wave power generation, will make it a more cost-efficient form of wave energy.

The SeaPower Platform extracts energy from deep water ocean waves by reacting to long prevailing wavelengths in high resource sites.

Solution – Accurate DTD-P Parallel Shaft Reaction Torque Transducer
“We chose the DTD-P torque transducer for its high accuracy and compact size which we needed for tank testing the SeaPower Platform,” explains Andy Hall, Director at 4c Engineering.

  • Designed for In-Line Static or Semi-Rotary Torque Measurement
  • Capacities: 0-10Nm to 0-10kNm
  • High Accuracy – Ideal for Calibration, Development and Testing Applications
  • Accuracy: <±0.15% / Full Scale Output
  • Customised Capacities, Shaft and Configuration Options Available
  • IP67 Waterproof and IP68 Fully Submersible Versions Available

Complete Torque Monitoring System
Applied Measurements Ltd provided 4c Engineering with a DTD-P 100Nm parallel shaft torque sensor fitted with an ICA4H miniature load cell amplifier, calibrated to UKAS traceable standards and sealed to IP68 to allow complete submersion. This complete torque measuring system enabled their engineers to reliably and accurately monitor the torque applied by the WEC as it responded to waves in the test tank.

Save on Installation Time
The DTD-P torque transducer has keyed parallel shaft connections for in-line static or semi-rotary torque measurement in capacities from 0-10Nm up to 0-10kNm (custom capacities readily available). This version was fitted with a flying lead, however versions with an integral bayonet lock military connector are also available which promise simple and easy connection.

Guaranteed High Accuracy
The DTD-P torque transducer is highly accurate to better than ±0.15% (typically ±0.05%) of the full scale output, making it ideal for this high precision development and testing application. Additional applications include the testing of electrical motors, hydraulic pumps, automotive transmissions, steering systems and aircraft actuators.

Need a Specific Design?
The DTD-P torque transducer can be customised with bespoke shaft, configuration options and capacities (to 50kNm+) specific to your application. For 4c Engineering we customised the design of the DTD-P torque transducer to IP68 submersible for continuous use underwater to 1m, which was essential for use in the wave test tank.

High Stability, Fast Response, ICA4H Miniature Load Cell Amplifier
“The high speed, reliability and clean output of the ICA4H miniature amplifier enabled the data to be analysed immediately after each test.” says Andy Hall.

  • Very Compact 19mm Diameter
  • Low Current Consumption
  • High Speed 1kHz Bandwidth (max.)
  • 4-20mA (3-wire) Output (10 to 30Vdc supply)

Very Compact
To deliver a conditioned load cell output signal we supplied the DTD-P torque transducer with an ICA4H high performance miniature load cell amplifier. The ICA miniature load cell amplifiers are very compact at only 19mm in diameter allowing them to fit inside the body of most load cells. In this application the ICA4H was supplied in a gel filled IP68 immersion protected compact enclosure (see image above) along with 10 metres of cable making it suitable for this underwater application.

With High Speed Response
The engineers at 4c Engineering needed to have a quick and reliable way to process the power take-off torque data from the tests, to determine the power capture and effects of the control settings before running the next test. The ICA4H miniature load cell amplifier was chosen not only for its high stability and compact size but also for its 1000Hz fast response.


A sea platform off the Galway (Ireland) Coast – not far from the Read-out offices.

@AppMeas @4c_Eng #power #PAuto


Motors that let you know when it’s time for a service.

30/07/2018

Simone Wendler, food and beverage segment manager for ABB’s motors and generators business, explains what to expect from a new generation of wireless motor sensor that offers powerful data collection and analytics in a small package.

Nearly all of the motor technology that we still use today was invented over a period of seventy years from 1820–1890, with the first commutated DC electric motor invented by British scientist William Sturgeon in 1833. Clearly, production processes — and the resultant demands on equipment — have changed since then and there is a lot that modern businesses can do to keep pace with the latest technology. 

William Sturgeon – 1783 – 1850

It is estimated that electric motors (pdf) account for 45 per cent of global electricity demand. That’s not surprising when you consider that they’re used to drive everything from pumps and fans to compressors in industries as varied as industrial, commercial, agricultural and transport. The problem is that increasingly complex food and beverage segments place a demand on motors to run continuously for long periods of time. This can lead to premature failure of the motor if it is not monitored closely.

In situations like this, carrying out traditional motor condition monitoring is an expensive and time consuming process. For most businesses that use low voltage motors, it’s often cheaper to simply run the motor until it fails and then replace it with another one. The consequence is that plants face unexpected downtime, lost production and possible secondary damage to other equipment. However, this approach can lead to spoilage of perishable food and drink items when the motor fails, forcing factory staff to spend precious time cleaning and preparing equipment to return it to operation.

The rise of the Industrial Internet of Things (IIoT) combined with a greater focus on energy efficiency, means that businesses no longer need to run motors until they fail. Instead, new technology opens up opportunities to make a drastic improvement to operations. With IIoT devices, businesses can make use of better big-data analytics and machine-to-machine (M2M) communication to improve energy efficiency and diagnose faults ahead of time. IIoT devices enable enhanced condition monitoring, allowing maintenance engineers to remotely monitor and collect operational trend data to minimize unexpected downtime.

Although this is great for future smart factories, it’s not feasible for plant managers to replace an entire fleet of analog motors today. Although modern, three-phase induction motors are much more efficient, smaller and lighter than motors from 120 years ago, the basic concept has not changed much. This creates a barrier for businesses that want to adopt smart technology but simply don’t have the resources to overhaul entire systems.

To address this problem, ABB has developed the ABB AbilityTM Smart Sensor for low voltage motors. The smart sensor can be retrofitted to many types of existing low voltage motors in minutes. It attaches to the motor frame without wires and uses Bluetooth Low Energy to communicate operational data to a smartphone app, desktop PC or even in encrypted form to the cloud for advanced analytics.

The sensor collects data including: various types of vibration, bearing health, cooling efficiency, airgap eccentricity, rotor winding health, skin temperature, energy consumption, loading, operating hours, number of starts and RPM speed.

The result is that the motor lets the operator know when it’s time for a service. Advanced analytics from the cloud can also provide advice on the status and health of the entire fleet. Data collected by ABB shows that the smart sensor can help users reduce motor downtime by up to 70 per cent, extend the lifetime by as much as 30 per cent and lower energy use by up to 10 per cent, a clear indicator that predictive, rather than reactive, maintenance increases reliability.

So, while we’ve come a long way since the days of William Sturgeon and the first commercial motor, plant managers looking to take the next steps should look closely at smart sensing and condition monitoring to truly embrace the age of IIoT.

@ABBgroupnews #PAuto #IIoT

Secure remote access in manufacturing.

24/07/2018
Jonathan Wilkins, marketing director of obsolete industrial parts supplier EU Automation, discusses secure remote access and the challenges it presents.

Whether you’re working from home, picking up e-mails on the go or away on business, it’s usually possible to remotely access you company’s network. Though easy to implement in many enterprises, complexity and security present hefty barriers to many industrial businesses

Industry 4.0 provides an opportunity for manufacturers to obtain detailed insights on production. Based on data from connected devices, plant managers can spot inefficiencies, reduce costs and minimise downtime. To do this effectively, it is useful to be able to access data and information remotely. However, this can present challenges in keeping operations secure.

Secure remote access is defined as the ability of an organisation’s users to access its non-public computing resources from locations other than the organisation’s facilities. It offers many benefits such as enabling the monitoring of multiple plants without travel or even staffing being necessary. As well as monitoring, maintenance or troubleshooting is possible from afar. According to data collected from experienced support engineers, an estimated 60 to 70 per cent of machine problems require a simple fix, such a software upgrade or minor parameter changes – which can be done remotely.

Remote access reduces the cost and time needed for maintenance and troubleshooting and can reduce downtime. For example, by using predictive analytics, component failures can be predicted in advance and a replacement part ordered from a reliable supplier, such as EU Automation. This streamlines the process for the maintenance technician, flagging an error instantly, even if they are not on site.

The challenges of remote access
There are still significant challenges to remote access of industrial control systems, including security, connectivity and complexity. Traditional remote-access includes virtual private networking (VPN) and remote desktop connection (RDC). These technologies are complex, expensive and lack the flexibility and intelligence manufacturers require.

Additional complexity added by traditional technologies can increase security vulnerabilities. Industrial control systems were not typically designed to be connected, and using a VPN connects the system to the IT network, increasing the attack surface. It also means if a hacker can access one point of the system, it can access it all. This was the case in attacks on the Ukrainian power grid and the US chain, Target.

To overcome these issues, manufacturers require a secure, flexible and scalable approach to managing machines remotely. One option that can achieve this is cloud-based access, which uses a remote gateway, a cloud server and a client software to flexibly access equipment from a remote location. In this way, legacy equipment can be connected to the cloud, so that it can be managed and analysed in real-time.

Most manufacturers find that the benefits of remote access can offer outweigh the investment and operational risks. To counteract them, businesses should put together a security approach to mitigate the additional risks remote access introduces. This often involves incorporating layers of security so that if one section is breached, the entire control system is not vulnerable.

When implementing remote access into an industrial control system, manufacturers must weigh up all available options. It’s crucial to ensure your system is as secure as possible to keep systems safe when accessed remotely, whether the user is working from home, on the go, or away on business.

@euautomation #PAuto #Industrie4

High frequency monitoring needed to protect UK rivers!

29/06/2018
Nigel Grimsley from OTT Hydrometry describes relatively new technologies that have overcome traditional barriers to the continuous monitoring of phosphate and nitrate.

The science behind nutrient pollution in rivers is still poorly understood despite the fact that nitrate and phosphate concentrations in Britain’s rivers are mostly unacceptable, although an element of uncertainty exists about what an acceptable level actually is. Key to improving our understanding of the sources and impacts of nutrient pollution is high-resolution monitoring across a broad spectrum of river types.

Background

Green Box Hydro Cycle

Phosphates and nitrates occur naturally in the environment, and are essential nutrients that support the growth of aquatic organisms. However, water resources are under constant pressure from both point and diffuse sources of nutrients. Under certain conditions, such as warm, sunny weather and slow moving water, elevated nutrient concentrations can promote the growth of nuisance phytoplankton causing algal blooms (eurtrophication). These blooms can dramatically affect aquatic ecology in a number of ways. High densities of algal biomass within the water column, or, in extreme cases, blankets of algae on the water surface, prevent light from reaching submerged plants. Also, some algae, and the bacteria that feed on decaying algae, produce toxins. In combination, these two effects can lower dissolved oxygen levels and potentially kill fish and other organisms. In consequence, aquatic ecology is damaged and the water becomes unsuitable for human recreation and more expensive to treat for drinking purposes.

In its State of the Environment report, February 2018, the British Environment Agency said: “Unacceptable levels of phosphorus in over half of English rivers, usually due to sewage effluent and pollution from farm land, chokes wildlife as algal blooms use up their oxygen. Groundwater quality is currently deteriorating. This vital source of drinking water is often heavily polluted with nitrates, mainly from agriculture.”

Good ecological status
The EU Water Framework Directive (WFD) requires Britain to achieve ‘good status’ of all water bodies (including rivers, streams, lakes, estuaries, coastal waters and groundwater) by 2015. However, only 36% of water bodies were classified as ‘good’ or better in 2012. Nutrient water quality standards are set by the Department for Environment, Food & Rural Affairs (DEFRA), so for example, phosphorus water quality standards have been set, and vary according to the alkalinity and height above mean sea level of the river. Interestingly, the standards were initially set in 2009, but in 75% of rivers with clear ecological impacts of nutrient enrichment, the existing standards produced phosphorus classifications of good or even high status, so the phosphorus standards were lowered.

Highlighting the need for better understanding of the relationships between nutrients and ecological status, Dr Mike Bowes from the Centre for Ecology & Hydrology has published research, with others, in which the effects of varying soluble reactive phosphate (SRP) concentrations on periphyton growth rate (mixture of algae and microbes that typically cover submerged surfaces) where determined in 9 different rivers from around Britain. In all of these experiments, significantly increasing SRP concentrations in the river water for sustained periods (usually c. 9 days) did not increase periphyton growth rate or biomass. This indicates that in most rivers, phosphorus concentrations are in excess, and therefore the process of eutrophication (typified by excessive algal blooms and loss of macrophytes – aquatic plants) is not necessarily caused by intermittent increases in SRP.

Clearly, more research is necessary to more fully understand the effects of nutrient enrichment, and the causes of algal blooms.

Upstream challenge
Headwater streams represent more than 70% of the streams and rivers in Britain, however, because of their number, location and the lack of regulatory requirement for continuous monitoring, headwater streams are rarely monitored for nutrient status. Traditional monitoring of upland streams has relied on either manual sampling or the collection of samples from automatic samplers. Nevertheless, research has shown that upland streams are less impaired by nutrient pollution than lowland rivers, but because of their size and limited dilution capacity they are more susceptible to nutrient impairment.

References
• Bowes, M. J., Gozzard, E., Johnson, A. C., Scarlett, P. M., Roberts, C., Read, D. S., et al. (2012a). Spatial and temporal changes in chlorophyll-a concentrations in the River Thames basin, UK: are phosphorus concentrations beginning to limit phytoplankton biomass? Sci. Total Environ. 426, 45–55. doi: 10.1016/j.scitotenv. 2012.02.056
• Bowes, M. J., Ings, N. L., McCall, S. J., Warwick, A., Barrett, C., Wickham, H. D., et al. (2012b). Nutrient and light limitation of periphyton in the River Thames: implications for catchment management. Sci. Total Environ. 434, 201–212. doi: 10.1016/j.scitotenv.2011.09.082
• Dodds, W. K., Smith, V. H., and Lohman, K. (2002). Nitrogen and phosphorus relationships to benthic algal biomass in temperate streams. Can. J. Fish. Aquat Sci. 59, 865–874. doi: 10.1139/f02-063
• McCall, S. J., Bowes, M. J., Warnaars, T. A., Hale, M. S., Smith, J. T., Warwick, A., et al. (2014). Impacts of phosphorus and nitrogen enrichment on periphyton accrual in the River Rede, Northumberland, UK. Inland Waters 4, 121–132. doi: 10.5268/IW-4.2.692
• McCall, S. J., Hale, M. S., Smith, J. T., Read, D. S., and Bowes, M. J. (2017). Impacts of phosphorus concentration and light intensity on river periphyton biomass and community structure. Hydrobiologia 792, 315–330. doi: 10.1007/s10750-016-3067-1

Monitoring technology
Sampling for laboratory analysis can be a costly and time-consuming activity, particularly at upland streams in remote locations with difficult access. In addition, spot sampling reveals nutrient levels at a specific moment in time, and therefore risks missing concentration spikes. Continuous monitoring is therefore generally preferred, but in the past this has been difficult to achieve with the technology available because of its requirement for frequent re-calibration and mains power.

High resolution SRP monitoring has been made possible in almost any location with the launch by OTT Hydromet of the the ‘HydroCycle PO4’ which is a battery-powered wet chemistry analyser for the continuous analysis of SRP. Typically, the HydroCycle PO4 is deployed into the river for monitoring purposes, but recent work by the Environment Agency has deployed it in a flow-through chamber for measuring extracted water.

The HydroCycle PO4 methodology is based on US EPA standard methods, employing pre-mixed, colour coded cartridges for simple reagent replacement in the field. Weighing less than 8kg fully loaded with reagents, it is quick and easy to deploy, even in remote locations. The instrument has an internal data logger with 1 GB capacity, and in combination with telemetry, it provides operators with near real-time access to monitoring data for SRP.

The quality of the instrument’s data is underpinned by QA/QC processing in conjunction with an on-board NIST standard, delivering scientifically defensible results. Engineered to take measurements at high oxygen saturation, and with a large surface area filter for enhanced performance during sediment events, the instrument employs advanced fluidics, that are resistant to the bubbles that can plague wet chemistry sensors.

Environment Agency application
The National Laboratory Service Instrumentation team (NLSI) provides support to all high resolution water quality monitoring activities undertaken across the Agency, underpinning the EA’s statutory responsibilities such as the WFD, the Urban Waste Water Directive and Statutory Surface Water Monitoring Programmes. It also makes a significant contribution to partnership projects such as Demonstration Test Catchments and Catchments Sensitive Farming. Technical Lead Matt Loewenthal says: “We provide the Agency and commercial clients with monitoring systems and associated equipment to meet their precise needs. This includes, of course, nutrient monitoring, which is a major interest for everyone involved with water resources.”

Matt’s team has developed water quality monitoring systems that deliver high resolution remote monitoring with equipment that is quick and easy to deploy. There are two main options. The ‘green box’ is a fully instrumented cabinet that can be installed adjacent to a water resource, drawing water and passing it though a flow-through container with sensors for parameters such as Temperature Dissolved Oxygen, Ammonium, Turbidity, Conductivity pH and Chlorophyll a. Each system is fitted with telemetry so that real-time data is made instantly available to users on the cloud.

Conscious of the need to better understand the role of P in rivers, Matt’s team has integrated a HydroCycle PO4 into its monitoring systems as a development project.
Matt says: “It’s currently the only system that can be integrated with all of our remote monitoring systems. Because it’s portable, and runs on 12 volts, it has been relatively easy to integrate into our modular monitoring and telemetry systems.

“The HydroCycle PO4 measures SRP so if we need to monitor other forms of P, we will use an auto sampler or deploy a mains-powered monitor. However, monitoring SRP is important because this is the form of P that is most readily available to algae and plants.”

Explaining the advantages of high resolution P monitoring, Matt refers to a deployment on the River Dore. “The data shows background levels of 300 µg P/l, rising to 600 µg P/l following heavy rain, indicating high levels of P in run-off.”

Nitrate
Similar to phosphates, excessive nitrate levels can have a significant impact on water quality. In addition, nitrates are highly mobile and can contaminate groundwater, with serious consequences for wells and drinking water treatment. Nitrate concentrations are therefore of major interest to the EA, but traditional monitoring technology has proved inadequate for long-term monitoring because of a frequent recalibration requirement. To address this need, which exists globally, OTT Hydromet developed the SUNA V2, which is an optical nitrate sensor, providing high levels of accuracy and precision in both freshwater and seawater.

The NLSI has evaluated the SUNA V2 in well water and Matt says: “It performed well – we took grab samples for laboratory analysis and the SUNA data matched the lab data perfectly. We are therefore excited about the opportunity this presents to measure nitrate continuously, because this will inform our understanding of nitrate pollution and its sources, as well as the relationship between groundwater and surface water.”

Summary
The new capability for high-resolution monitoring of nutrients such as phosphorus will enable improved understanding of its effects on ecological status, and in turn will inform decisions on what acceptable P concentrations will be for individual rivers. This is vitally important because the cost of removing P from wastewater can be high, so the requirements and discharge limits that are placed on industrial and wastewater companies need to be science based and supported by reliable data. Similarly, nitrate pollution from fertilizer runoff, industrial activities and wastewater discharge, has been difficult to monitor effectively in the past because of the technology limitations. So, as improved monitoring equipment is developed, it will be possible to better understand the sources and effects, and thereby implement effective prevention and mitigation strategies.

@OTTHydrometry @EnvAgency @CEHScienceNews #Water #Environment

Inertial Measurement Unit – essential in self-driving cars!

26/06/2018
They are here or on the way – the self-driving car! It is one of revolutions which could change lives in the 21st century. Here Mike Horton, Chief Technical Officer at ACEINNA discusses seven reasons your life depends on an accurate IMU (Inertial Measurement Unit) in these self-driving cars.

An inertial measurement unit (IMU) is a device that directly measures the three linear acceleration components and the three rotational rate components (6-DOF) of a vehicle. An IMU is unique among the sensors typically found in an autonomous vehicle because an IMU requires no connection or knowledge of the external world.

A self-driving car requires many different technologies, for example — LIDAR to create a precise 3-D image of the local surroundings, radar for ranging targets using a different part of the EM spectrum, cameras to read signs and detect color, high-definition maps for localization, and more. Unlike the IMU, each of these technologies involves the external environment in order to provide data back to the software stack for localization, perception, and control. This unique “independent” property of the IMU, makes it a core technology for both safety and sensor-fusion.

An Accurate IMU can Mitigate Issues in RED

The following of Seven Top Reasons is just a start, additional reasons and benefits of an accurate IMU are welcomed as responses to this post either as comments or direct to the author himself at ACCEINNA.

•1 Safety First
The system engineer needs to consider every scenario and always have a back up plan. Failure Mode Effects Analysis (FMEA) formalizes this requirement into design requirements for risk mitigation. FMEA will ask what happens if the LIDAR, Radar, and Cameras all fail at the same time? An IMU can dead-reckon for a short period of time, meaning it can determine full position and attitude independently for a short while. An IMU alone can slow the vehicle down in a controlled way and bring it to a stop … providing the best practical outcome in a bad situation. While this may seem like a contrived requirement, it turns out to be a fundamental one to a mature safety approach.

•2 A Good Attitude
An accurate IMU can determine and track attitude precisely. We often think of a car’s position or location, but when driving the direction or heading is equally crucial. Driving the slightly wrong direction even for a brief instant, will put you in the wrong lane. Dynamic control of the vehicle requires sensors with dynamic response, and an accurate IMU does a nice job of tracking dynamic attitude and position changes accurately. Due to its fully environment independent nature, an IMU can even track the really tricky cases such as the slipping and skidding where tires lose traction. A precise attitude measurement is often useful an input into other algorithms. While LIDAR and Cameras can be useful in determining attitude, GPS is often pretty useless. Finally, a stable independent attitude reference has value in calibration and alignment.

•3 Accurate Lane Keeping

During turns, an accurate IMU plays a key role in lane keeping

It turns out when humans are not distracted or drunk, we are typically not bad at driving. A typical driver can hold their position in a lane to better than 10cm. This is actually really tight. If an autonomous vehicle wanders in its lane, then it will appear to be a bad driver. As an example during a turn, poor lane keeping could easily result in an accident. The IMU is a key dynamic sensor to steer the vehicle dynamically, moreover the IMU can maintain a better than 30cm accuracy level for short periods (up to ten seconds) when other sensors go offline. The IMU is also used in algorithms that can cross compare multiple ways to determine position/location and then assign a certainty to the overall localization estimate. Without the IMU, it maybe impossible to even know when the location error from a LIDAR solution has degraded

•4 LIDAR is Still Expensive
Tesla is famous for its “No LIDAR Required” approach to autopilot technology. If you don’t have LIDAR, a good IMU is even more critical because camera-based localization of the vehicle will have more frequent periods of low-accuracy simply depending on what is in the camera scene or the external lighting conditions. Camera based localization uses “SIFT” feature tracking in the captured images to compute attitude. If the camera is not stereo (often the case) inertial data from the IMU itself is also a core part of the math to compute the position and attitude in the first place.

•5 Compute is not Free
The powerful combination of high-accuracy LIDAR and high-definition maps is at the core of the most advanced Level 4 self-driving approaches such as those being tested by Cruise and Waymo. In these systems LIDAR scans are in real-time matched to the HD map using convolutional signal processing techniques. Based on the match, the precise location of vehicle and attitude is estimated. This process is computationally expensive. While we all like to believe the cost of compute is vanishingly small, on a vehicle it simply is not that cheap. The more accurately the algorithm knows its initial position and attitude, the less computation required to compute the best match. In addition, by using IMU data, the risk of the algorithm getting stuck in a local minimum of HD map data is reduced.

•6 GPS/INS: Making High-Accuracy GPS Work
In today’s production vehicles GPS systems use low-cost single-frequency receivers. This makes the GPS accuracy pretty useless for vehicle automation. However, low-cost multi-frequency GPS is on the way from several silicon suppliers. On top of this upcoming silicon, network-based correction solutions such as RTK and PPP can provide GPS fixes to centimeter level accuracy under ideal conditions. However, these solutions are very sensitive to the environment — such as bridges, trees, and buildings. It is well established that the way to overcome this challenge and improve precisions GPS reliability is to use high-accuracy IMU aiding at a low-level in the position solution. Such GPS/INS techniques include tightly-coupled and ultra-tightly-coupled GPS/INS. These are coming soon to the automotive market (stay tuned for exciting updates).

•7 Car’s Already Need an IMU
Turns out production automobiles already have anywhere from 1/3 of an IMU to a full IMU on board. Vehicle stability systems rely heavily on a Z-axis gyro and lateral X-Y accelerometers. Roll-over detection relies on a gyro mounted with its sensitive axis in the direction of travel. These sensors have been part of the vehicles safety systems for over a decade now. The only problem is that the sensor accuracy is typically too low to be of use for the prior six uses cases. So why not upgrade the vehicle to a high-accuracy IMU and help it drive autonomously? The main barrier has been cost.
Aceinna along with other companies in the industry are working hard to remove the cost barrier.


Pushing the boundary of price-performance

@MEMSsensortech #Automotive