Overcoming extreme environments with embedded system solutions
Sponsored content [Friday 15 March 2013]
The defense, aerospace, transportation, outdoor, mining development, high temperature, and chemical industry fields often encounter extreme or corrosive chemical environments. Advantech, which provides services for long-term management of embedded applications, has proposed embedded application solutions for these types of extreme environments.
Extreme environments bring new challenges and opportunities for embedded applications
Aaron Su, Embedded Core Group/COM Product Manager for Advantech, indicated that industrial automation as well as cloud and smart computing are the two major trends that will spur a new wave of market opportunities for embedded applications. Extreme temperature changes provide a great challenge for the temperature tolerance of embedded devices. Extreme climates caused by greenhouse effects as well as resource depletion challenges are similar to challenges faced by a coal mine digging machine after it has dug the surface and is moving underground, which has to overcome different geothermal and environmental pressures.
The key design features of extreme environment industrial control products are: higher product stability is required to reduce future maintenance costs; wide-range temperature embedded devices for single-task RTOS that do not require high computing capabilities; and longer warranty and supply periods. Risky industrial control applications for the military, aerospace, transportation, outdoor, mineral resources development, high-temperature, or chemical fields are all within the scope of extreme environment applications. To overcome extreme environments, embedded systems must be heat resistant as well as provide compression and seismic reliability, stability, waterproofing, and anti-corrosion features. These requirements can be overcome through designs, materials, and stringent verification.
Embedded solutions for wide-range temperature fluctuations
Su indicated that from the initial design stage, materials and parts that do not meet the working temperature requirements must first be identified to save time and subsequent development. Product design must go through functional design testing as well as heat source simulations and analysis. In particular, to ensure stable operation in a wide-range temperature environment when some materials and parts in the wide-range temperature product are still under normal temperature specifications, Advantech has designed onboard overheat protection mechanisms to prevent materials and parts from overheating and crashing, as well as low temperature activation to enable materials and parts to reach working temperatures rapidly and maintain normal operation. In addition, power efficiency must be considered to enable devices to operate longer in areas that lack electric sockets.
Wide-range temperature product verification is divided into developmental verification and shipping verification stages. During the developmental stage, engineering samples/systems are fed into a chamber and then activated to perform full-load operations; thermal shock tests are then performed by rapidly and repeatedly moving the test products between high and low temperature environments; and finally, over 50 hours of full-load burn-in and power outage/restart power cycling tests are also performed. 100% of the products must also be tested during mass production where each systems must be burnt-in to confirm normal operations before shipping to the customers. In addition to burnt-in tests, reliability tests such as Highly Accelerated Life Testing (HALT) can also be performed to detect product weaknesses and select appropriate improvement or reinforcement measures to improve the tolerability of products.
Waterproof/corrosion resistance/seismic solutions for embedded products and peripherals
Sulfide particles in the air around ships, chemical plants, outdoor mass transportation (such as trains), and industrialized countries with severe air pollution problems often cause corrosion and damage to embedded motherboards. Su further introduced waterproofing and anti-corrosion applications and indicated that moisture-proof, dust-proof, anti-corrosion, and anti-friction effects can be achieved by performing Conformal Coating Services on the PCB surfaces of motherboards. Materials used include acrylic (AR), urethane (UR), silicone, and epoxy (ER). Each of these materials has unique repair, moisture resistance, abrasion resistance, solvent resistance, mechanical tension, and elasticity characteristics that are suitable for certain objectives.
Protective coatings can be applied manually or mechanically. Manual coating is used during small test production, and the drawback is that it is unable to achieve a uniform coating. Advantech provides mechanical automation coating services using acrylic resin or organic silicon as the coating materials. Under IPC-610D specifications, the maximum coating surface is 450mm by 450mm with thickness ranging from 0.5mm to 5mm. On average, coating for one motherboard can be completed in three minutes. The coating can enhance the waterproof, moisture-proof, anti-salt atmosphere, anti-friction, anti-metal particle, and anti-bacterial capabilities of boards.
There are currently four solutions that can improve the shockproof and warpage-resistant capabilities of a system: solder chips such as CPU and memory onto the motherboard as much as possible; apply glue on both sides of memory modules to avoid shaking and shedding; use locked connectors with retaining clips for connectors/slots; and use lockable flash storage modules.
The IEC60068-2-64 specification is compiled for anti-vibration tests where the maximum vibration acceleration force and frequency can reach 5G and 5Hz to 500Hz. The IEC60068-2-29 specification is compiled for impact tests (with the maximum impact force set at 15G). In addition, Corner Bonding can be performed on chips to increase the PCB thickness as a solution to prevent PCB board warpage from causing BGA chips to crack.
Su pointed out that Advantech also provides a full series of industrial wide-range temperature peripheral devices. These devices include the SQFlash storage module series (with PATA/SATA/USB interfaces and a three-year warranty) and the SQRAM memory module series (wide-range temperature, Goldfinger 30nm plating processing, Fix Die chip bonding, and thermal sensor designs). The wireless transmission module provides wide-range temperature and seven-year warranty as well as wide-range temperature and high illumination touch control display equipment. Advantech's Rugged Industrial Display Solution enables normal operation between minus 20 to 60 degrees C and provides readability of 1,200nits under normal sunlight. The solutions include rugged, stand-alone monitors with IP54 front panel protection and tempered glass. The life span of the backlight reaches 50,000 hours.
ARM's opportunity in low-end embedded devices and intelligent nodes
At present, hardware developers such as AMD, Freescale, TI, and Nvidia have adopted industry specifications such as PCI Express, USB, and SATA. Microsoft and Google have launched the Windows RT and Android operating systems, respectively. Industrial control field players such as Kontron, Congatec, and MSC are promoting Q7 and ULP form factors. According to ARM's market data, in 2011, ARM's mobile device market saw a 15% gain and reached US$4.5 billion, the embedded device market division saw a 70% gain and reached US$7 billion, enterprise applications had a 30% gain and reached US$1.3 billion, and household devices had a 10% gain and reached US$300 million.
Su said he believes that the ARM RISC architecture with low power consumption (<3W), wide-range temperature (minus 40- to 105-degrees C), SoC design, and rapid boot features should be preferred by customers. At present, ARM's products are low priced. However, overall development costs are higher than for x86, and information acquisition costs are not as diverse. Because ARM's level of standardization is not high and its cases are mostly project design in nature, there is a higher moral risk for customers and specific hold up costs. This restricts ARM's penetration in the low-end embedded application market.
To integrate industrial control applications into cloud computing architectures under the intelligent earth concept, sensors provide downstream transmit data using wireless or wired methods to intelligent nodes with ARM cores. Data are then connected to a computing core (x86-based) at the next higher level and then are eventually uploaded to the cloud server. The functions of the intelligent nodes are to connect the sensors and the cloud as well as provide the underlying intelligent computing capacity for the cloud to disperse load and make the system more efficient.
Strengthening ARM through early designs and integrated support
Based on Su's analyses, RISC clients are categorized as in-house, outsourcing, early-comers (pragmatists), late-comers (followers), and laggards. The first two categories focus on product price/overall development costs. The early-comers (pragmatists) appear in the design standard stage and are restricted by company size and development capabilities; therefore, they cannot independently develop ARM core applications and need to switch to x86 solutions. This category of clients focuses mostly on the first four costs mentioned above. Late-comers (followers) select ARM solutions due to market trends, low RISC price factors, and customer demand; and mostly focus on price/overall development costs and specific hold up costs. The characteristics of laggards are that they refuse to integrate ARM solutions due to non-technical or non-market driven reasons, such as being Intel partners.
Promoting ARM standardization can resolve the moral risk costs and specific hold up costs; closely connect the upstream and downstream to resolve information acquisition costs; and resolve these costs by replacing trade with a collaborative design methodology.
Regarding form factor standardization; Congatec launched the Qseven(Q7) in 2008 and Advantech launched its RTX 1.0 in 2008, Kontron during late 2012, and RTX 2.0 for rugged applications in 2013. RTX 2.0's shockproof design and 2mm PCB thickness can prevent board warping and cracking. RTX 2.0 adopts the B2B connector which is similar to that of ETX specifications, has a multi-function heat-sink design, and is more suitable for rugged industrial control applications than Q7 and ULP. Finally, Su mentioned that the ARM RISC architecture's collaborative design methodology can replace the traditional trade model. For example, Advantech provided R&D manpower and design support from the early developmental stages of U-Boot and BSP/Driver. After the products began selling to the client-side, Advantech continued to provide design-in services to assist clients in completing their projects, which in turn reduced the clients' difficulty in adopting the ARM-core products.
Aaron Su, Embedded Core Group/COM Product Manager for Advantech