Rabu, 25 Februari 2009

Satellite Receiving Antennas

All satellite dishes incorporate a parabolic curve into the design of their bowl-shaped reflectors. The parabolic curve has the property of reflecting all incident rays arriving along the reflector's axis of symmetry to a common focus located to the front and center. The parabolic antenna's ability to amplify signals is primarily governed by the accuracy of this parabolic curve. Poor antenna performance can result from inaccuracies in the dies used to manufacture the reflector surfaces. More often, however, low antenna efficiencies are caused by the installer's failure to grasp the importance of using good antenna assembly techniques.

Antenna Materials & Construction

The reflector must be constructed out of metal in order to reflect the incoming microwave signals. Some antenna reflectors appear to be manufactured out of plastic or Fiberglas; however, these dishes contain an embedded metal mesh material that reflects the incoming satellite signals.
Solid one-piece antennas are most often the best performers because there are no assembly errors and they will maintain their exact shape over the lifetime of the system. Solid petalized antennas constructed out of four or more segments are generally the next best performers. Potential assembly errors are limited to variations along the seams between petals.

The installer can easily visually inspect these seams during assembly to ensure that there are no variations in the surface curve from one petal to the next. One-piece and petalized antennas are also available in a perforated form. The diameter of the perforation holes is a function of signal wavelength: too small to pass or resonate with the wavelength of the incoming microwave signals but large enough to pass light in order to minimize the antenna's environmental impact.

Mesh antennas are the most susceptible to construction errors. The two-part construction process consists of the building of a support frame and a series of flexible mesh panels. The installer attaches the mesh to the frame using a series of metal clips or sheet metal screws. Mesh antennas also are highly susceptible to environmental effects. Heavy wind storms, for example, can loosen the clips holding the mesh to the frame and distort the curve from its original shape or even blow out one or more of the mesh panels. The installer should examine the antenna at intervals during the installation process. Close attention should be paid to how the various petals fit together. The reflector surface should appear to be continuous, with minimal variation from petal to petal and few noticeable bumps or waves along the surface of mesh antennas. Antenna symmetry is also very important.


Improper construction of a petalized antenna can warp the reflector curvature. The installer should sight along a side view of the reflector from the near to far edge of the antenna rim. If the near and far rims of the dish do not line up in parallel with each other then the installer will need to loosen the bolts holding the petals together and re tighten them in such as way that the reflector conforms to the manufacturer's intended shape. Another way to detect warp is to run strings across the antenna's rim. All strings should lightly touch over the center of the dish. Any gaps between strings indicate a flaw in the reflector surface.

Prime Focus Antennas

The basic design principle of the parabolic curve can be incorporated into antenna designs in a variety of ways. Dishes with a focal point directly at the front and center of the reflector are called prime focus antennas. Prime focus antennas are easy to construct and point toward the desired satellite. There are two main design disadvantages, however: the feedhorn and feed support structure block part of the reflector surface and the feedhorn must look back at the dish at such an angle that it can also intercept noise from the "hot" earth located directly behind the reflector.

The feedhorn's illumination of the antenna must be attenuated or tapered to minimize noise contribution from the perimeter of the dish. This design necessity acts to reduce the antenna's efficiency.Prime focus antennas use two different types of feedhorn support bracket. A three or four-legged support provides a rigid support structure for the feedhorn and LNB over the center of the dish and at the distance specified by the manufacturer. The main disadvantage of this structural approach is that it may be difficult to make minor variations in the focal length, that is the distance from reflector center to the lip of the feed opening.

The buttonhook structural design uses a single support member to position the LNB and feedhorn. This tubular leg can usually be slid in and out of a clamp or bracket at the center of the dish, allowing the installer to fine-tune the focal length. However, the buttonhook support may not always position the feed at the precise center of the dish, especially when the feedhorn is weighted down by multiple LNBs. Motorized dishes may experience feedhorn movement when the antenna is moved from one satellite to the next; heavy winds can also temporarily move the feedhorn away from the antenna's focus. Guy wire kits are available which the installer can use to provide additional structural rigidity to the buttonhook support if required for a given installation.

Offset-fed Antennas

The dish design of choice for most digital DTH systems is called an offset-fed antenna. Here the manufacturer uses a smaller subsection of the same parabolic curve used to produce prime focus antennas, but with a major axis in the north/south direction, and a smaller minor axis in the east/west direction. With the offset-fed design, the feedhorn is no longer positioned at the front and center of the reflector but rather offset to the bottom of the dish. However, the feed would be centrally located if we extended the parabolic curve of the offset fed dish to the full length of a prime focus parabola. The offset fed antenna design offers several distinct advantages over its prime focus counterparts.

There is no feedhorn blockage, an important consideration when the antenna aperture is less than one meter in diameter. Moreover, the offset angle at which the feedhorn tilts up toward the reflector is such that if the feed looks over the antenna's rim it will see the cold sky rather than the hot earth. Due to these advantages, the offset-fed antenna can achieve higher efficiency levels than prime focus antennas can generally attain. The low inclination angles required by offset antennas also may be beneficial in certain climate zones. In tropical or semi-tropical environments, rain will not collect inside the reflector. In cold weather climates, snow will slide off of the antenna surface rather than accumulating inside the reflector.

Cassegrain Antennas

The cassegrain antenna is most often used for dishes that exceed five meters in diameter. Its use is primarily restricted to uplink earth stations and cable TV head ends. The cassegrain design incorporates a small sub reflector located at the front and center of the dish. The sub reflector deflects the microwaves back toward the center of the reflector, where the feedhorn is actually mounted. Like the prime focus dish, the cassegrain antenna's view of the satellite is partially obscured, in this case by the sub reflector.

However, when the diameter of the dish exceeds 5m, the percentage of blockage is actually quite small. This type of antenna obtains higher efficiencies because the feedhorn looks up at the cold sky and the required illumination taper is reduced. The precise manufacturing tolerances required to implement this dual reflector approach, however, increases the manufacturing cost and adds complexity to the installation process.



Spherical Antennas

The spherical antenna design creates multiple focal points located to the front and center of the reflector, one for each available satellite. The curvature of the reflector is such that if extended it outward far enough along both axes it would become a sphere. Spherical antennas are primarily used for commercial SMATV and cable installations where the customer wishes to simultaneously receive multiple satellites with a single dish. These satellites must be within +/- 20 degrees of the reflector's axis of symmetry.

Planar Arrays



Some digital DTH systems in Japan and elsewhere have elected to use an alternate antenna design called the planar array. These flat antennas do not rely on the reflective principles used by all parabolic dishes. Therefore no feedhorn is required. Instead a grid of tiny elements is embedded into the antenna's surface. These elements have a size and shape which causes them to resonate with the incoming microwave signals. A spider's web of feed lines is used to interconnect all the resonant elements in such a way that their signal contributions are all combined in phase at a single terminal located at the center of the array which connects directly to the LNB.

Planar arrays are relatively unobtrusive: there is no feedhorn and the LNB is located to the rear of the antenna out of sight. Since these antennas are most always dedicated to the reception of a single satellite or constellation of collocated satellites, they can be mounted in a fixed position on an outer wall or rooftop. One main disadvantage of the planar array is its limited frequency bandwidth which is about 500 MHz. Parabolic antennas, however, have a broad bandwidth; a single dish, for example, can be used to receive S, C, and Ku-band satellite signals. Another disadvantage of the planar array is the high construction cost: more than four times the cost of manufacturing a feedhorn and parabolic reflector with equivalent signal amplification characteristics.

Antenna Gain and G/T

The gain of a satellite antenna is the measurement of its ability to amplify the incoming microwave signals. Gain, which is expressed in decibels, or dB, is primarily a function of antenna capture area or aperture: the larger the antenna aperture, the higher the antenna gain. Gain also is directly related to antenna beam width: the narrow corridor or "boresight" along which the antenna looks up at the sky.

The antenna's efficiency rating is the percentage of signal captured by the parabolic reflector that actually is received by the feedhorn. As we have previously seen, the feed-horn's illumination of the outer portion of the dish is attenuated or tapered, which leads us to conclude that antenna gain is not as important a factor as it might first appear to be. The ultimate figure of merit for all receiving antennas is the G/T (pronounced "G over T"); that is, the gain of the antenna (in dB) minus the noise temperature of the receiving system (in dB). A typical C-band DTH system will have a G/T of around 20 dB/K, while most Ku-band digital DTH systems have a G/T of 12.7 dB/K.

The more powerful the satellite signal, the lower the G/T value that will be needed at the receiving system down on the ground.The noise value (T) primarily comes from two sources. The antenna noise is a function of the amount of noise that the feedhorn sees as it looks over the antenna rim towards the hot earth (which has a noise temperature of 290 K). Antenna noise generally ranges between 30 and 50 K.

The noise contribution of the LNB's internal circuitry is the other major source of concern. C-band LNB performance now ranges as low as 20 K. If we add an antenna/feed noise of 40 K to LNB noise of 35 K = 75 K. Ten times the Logarithm of 75 K equals a (T) of 18.8 dB. A typical 1.8m diameter C-band antenna will produce a gain of 38 dB. Therefore the G/T of the system described above would be (G) 38 dB minus (T) 18.8 equals 19.2 dB/K.

Deep Versus Shallow Dishes

The parameters of the parabolic curve that the antenna designer selects can be adjusted to create a variety of focal length to antenna diameter (f/D) values. Antennas which have an f/D greater than .38 are said to be shallow, whereas dishes will an f/D less than .33 are said to be deep.Although the long focal length afforded by the shallow dish design increases the feedhorn's ability to illuminate the entire reflector surface, we have already seen that there are distinct disadvantages to doing this.

Moreover, antenna noise increases as antenna elevation increases. Shallow dishes are more susceptible to intercepting earth noise when pointing at low elevation angles. Finally, the shallow dish is more susceptible to picking up terrestrial interference from microwave relay stations. The deep dish trades off gain in order to lower antenna noise performance.

The deep-dish design is an attractive alternative for locations that potentially may experience terrestrial interference problems or at installations which require low antenna elevation angles. The deep-dish design positions the feedhorn relatively close to the rim of the reflector. Therefore the deep dish has a greater ability to shield the feedhorn from potential TI sources. However, the feedhorn is so close to the reflector that it cannot illuminate the entire surface.

Antenna Side Lobe Rejection

The explosive worldwide growth in satellite telecommunications is leading to closer spacing between satellites in geostationary orbit. What's more, the very latest satellites are transmitting higher-powered signals than ever before. Both of these developments act to increase the potential for interference from nearby or adjacent satellites. The perfect parabolic antenna would only receive signals from the satellite at which it was pointed while rejecting all signals coming from other directions.

In the real world, however, each antenna design will produce a main beam along the axis of symmetry as well as other beams of lower intensity that look out at adjacent angles. These beams of lower intensity are called "sidelobes". The goal of all satellite TV antenna manufacturers is to reduce the gain of these sidelobes to levels that are at a minimum of 15 dB below the gain of the main lobe. This level of sidelobe attenuation is usually sufficient for preventing adjacent satellites from causing interference to reception of the desired satellite.

The location off axis of each sidelobe is a function of antenna diameter and signal frequency. The installer can therefore select an antenna that is large enough to put the adjacent satellites in the first "null" of the antenna receiving pattern or use an antenna which has a sidelobe that is at least -15 dB down from the main beam.

Antenna Mounts

The steel mount and the bearing that supports the antenna reflector must be able to maintain a precise position once boresighted onto the desired satellite. A misalignment of the mount of as little as two inches can make the difference between perfect TV reception and no reception at all. The installer should check the rigidity of the mount by grasping the rim and gently shaking it to see if there is any "play" as wind or rainstorms may push the dish off of boresight, causing erratic reception.

All mounts incorporate adjustments that permit the installer to point the dish at the desired satellite. Digital DTH antennas commonly have what is known as a fixed mount that is adjusted once at the time of installation and then left alone thereafter. The fixed mount has separate settings for the required azimuth (compass bearing corrected to true north) and elevation (the angle at which the reflector tilts up at the sky). Motorized DTH antennas must rotate in an arc that mimics the curvature of the geostationary arc where all the satellites are located.

A modified form of the polar mount used by astronomers on their telescopes is used to achieve this effect. The axis of the modified polar mount must be aligned with the earth's axis of rotation at an angle that corresponds to the latitude of the receiving site. Precise tracking of the geostationary arc also requires a declination adjustment that tilts the antenna downward slightly in the direction of the geostationary arc. This modification to the polar mount is required because of the relative closeness of the satellites in comparison to the stars that astronomers view with polar mounted telescopes.


First published in Middle East Satellite Today magazine. Copyright 1998 Mark Long.

Putra-Design

Sony Company Profile, History and Culture, and SWOT

Sony Corporation Company Profile, History and Culture, and SWOT

Executive Summery :

Sony's current financial difficulties are tied into its corporate culture which were stated over 30 years ago. With such a large multinational corporation, greater planning and more use of strategies should be pursued. Sony could start with the implementation of a new mission statement, with profit and benefits of the company tied more closely to everyday operations. Internally, the four forces, the management, the designers, the production and the marketing should achieve better communication and cooperation.

Alliance and cooperation between competitors should also be actively sort after in order to create standards in new fields. Sony should aim at being the leader instead of being the maverick. As for cost cutting, Sony should seriously consider setting up operations in other Asian countries in order to take advantage of the cheap labour and the budding markets. Finally, diversification, instead of pursuing the fast changing and easily imitated consumer goods market, Sony should use its technological know-how for high-end business and office equipment.

With SWOT analysis and Porter's competitive forces model, we can view that the market is much more competitive with less profit margins and lead-time for product innovation. The conclusion is that change is needed in Sony. However,even with strategirial and structure change, the Sony spirit of innovation should remain intact because that is what made Sony grow and would make it stay strong.

Introduction

The first thing that comes to peoples minds of the company and products of Sony is its high-technology-filled-with-gadgets electronic goods and innovation. It was also this innovation that make Sony the greatest company that started in post-war Japan. Sony has used its innovation in building markets out of thin air, created a multibillion, multinational electronic empire with products such as the transistor radio, the Trinitron, the Walk-in and the VTR. that changed everyday household lives forever.

However, this consumer targeted quest for excellence and constant innovation instead of targeting mainly at profit also has a lot to do with current crisis Sony is facing - sales and profits are down or are slowing down, capital investment cost and R&D are climbing, competitors are moving in with copycats, the battle between VHS and Beta and the search for a smash hit product such as the Trinitron or the Walk-in.

This volatility and emphasis (or gambling) on new products instead of concentrating on profit and loss statements have always been a part of Sony since its beginning days. For each successful product (i.e. transistor radio and Trinitron), R&D cost often ran so high that the they pushed the firm to the verge of bankruptcy. This can also be seen through the eyes of the investor in which although sales have increased tremendously throughout the past twenty years, the stock price has remained relatively low.

History and Culture

The current Sony corporation has a unique culture which is firmly rooted in her history especially in relationship to her two founders, Masaru Ibuka and Akio Morita. Ibuka and Morita were both dedicated electrical engineers and geniuses above their business talents. Both gave insights and visions in what the company should make and how it should be made. Ibuka, especially, gave constant advice and suggestions to the engineers involved in projects from the earlier on transistor radios to Walkmans.

This created the umbrella strategy in which Sony operates under where the top management, especially Ibuka, Morita and now Norio Ohga gave the general direction in which the lower engineers actively learned, developed and improved on the vision/idea. Therefore, although there is a planned direction, the actual product development through launching is emergent with great flexibility.

Although the research and development section of Sony differs greatly from other companies with its great flexibility, Sony, in its essence is still a traditional Japanese company in many ways. There is life-time employment, with strong norms and values which in turn create strategies through their actions. Status is given (the crystal award) instead of bonuses (not significant amount) for superior achievement. There is also the strong seniority system such as the mentor and apprentice relationship that is typical of a Japanese firm. All this can be classified as the cultural school in which strategy formation is of collective behaviour. Collective vision and stress on human resource, which is typical of many Japanese, can be clearly seen in the mission statement "Management Policies".

Weaknesses and Threats

Referring to Exhibit 1, sales has slowed down considerably since the beginning of the 80s. In the domestic market, sales actually decreased by 7.22%. The overseas market expanded both in real terms and relative to total sales, but slowed down to around 10% a year. This can be seen as the vacuum period between one hit product, the Walkman, and its succession. As mentioned by Ibuka, business is conducted in a ten year cycle.

However, in the eighties, the product might still take a few years to develop, but the time reaping the results and profits might be much less. As seen in the VTR example, both the VHS and Beta were developed by Sony. However, in a short time, Matsushita could come up with a competitive product based on Sony's technology. Therefore, it is fair to say that other electronic firms would be able to copy Sony's technology in a much shorter time while offering more competitive prices. The margin for technology advancement is therefore diminishing.

Associated with innovation is the capital expenditure cost and return on investment ratio. As seen from Exhibit 1, capital expenditure has risen dramatically, especially in 1981, due to the automation of plants. However, the return on investment has decreased. Spending around 10% of sales on capital investment is by all company standards an extremely high figure. The question is that does this high rate of investment represent corresponding growth in profitability? As mentioned above, the diminishing returns from product innovation is apparent. However, the internal dimension also poses as much of a problem.

With its great freedom, research and development are divided into small teams which are free to pursue their interest with little reference to "how it will fit into a market, what the product can do, how well it will function or how it could be used by customers." Secret projects without management knowing about them until "secret reports" are submitted are of common practice.

With this kind of practice, there is lack of communication between management and R&D and threat of duplication of resources among the small groups. There is also a lack of general direction. This would be especially prominent when Ibuka and Morita, the symbolic leaders and founders retire. This is because the two in many ways act as the main guidance and bridge between management and the engineers. Therefore, there is also a succession problem.

Sony has always been a leader in technology, creating markets by looking for new markets where bigger, well-established companies are not a threat. However, new products such as VTR, the Walk-in and the Mavica involve both hardware and software. Sony can no longer just produce superb quality machines and expect them to sell. The software would also have to be available. For the Walkman, cassette tapes were well established but for the Beta system and Mavica, a standard has yet to be set. For example, the images of Mavica would be held on a high density magnetic disk but Kodak, 3M and Sony all have different systems and are not compatible. The Mavica system also stands alone with little compatibility with conventional systems and little transitional interfaces.

This leads to the problem of cooperation where Sony is often the maverick, alone creating markets. With Sony entering markets such as the VTR with no standards, it might be beneficial to both Sony and other vendors if they cooperated instead of competing on conflicting software that supports the systems. This could also be seen in Exhibit 2, the Porter competitive forces mode: new entrants from other Asian countries, other Japanese industry competitors, substitutes and buyers are all strong and much stronger than 20 years ago which reinforce the weakness of Sony acting alone.

Last but not least, Sony lacks strategy. Product development, manufacturing and marketing are all well established but the firm lacks any formal long term direction. The original mission statement is also outdated with its references to W.W.II. Short term strategy is also lacking and there is little emphasis on profit and accountability of research and development of products. The result : a company with strong components but unable to coordinate in a coherent way in order to achieve maximum potential.

Strengths and Opportunities

The greatest asset of Sony is of its human capital, especially its engineers which make up the R&D department. Their constant innovation is crucial for a consumer electronic firm which specializes in audio-visual equipment and the higher profit margin, which comes from being the leader of the pact. Subsidiaries are also well established, such as in the United States and Europe which give Sony a distinct local hands-on knowledge of the local market.

It also makes Sony an international corporation, bringing together the talents and best of strategies of both world to the organization. Besides the employees, the two founders, Ibuka and Morita also legends in their fields which they create vision and sense of direction for the organization. The also acts as bridges between the employees and the management.

The self promoting system and job rotating systems creates satisfaction for employees and give them greater exposure to all aspects of the business. Ideally, this would produce better products as engineers gain knowledge on consumer needs while marketing people engaged in the production and can give their point of view.

The innovative style also stems from the "never copy others" culture, the generous funding of the R&D and huge amounts in capital investments. As described by Ibuka,"It also stems from consumer driven in which technology is targeted at consumers or business while American electronic industry are spoiled be military and space applications."

Sony has been ahead in the race of Video Tape Recorders and digital imaging techniques in Mavica which both offer tremendous potential of household penetration and sales. It also has the opportunity to set up standards and dominate the field. Sony has also acquired enough technology to increase width by going into the high technology business fields. With the rise of the Asian countries, Sony also has the opportunity to make use of them for markets and for cheap labour.

Recommendations

Building of Strategy

With the succession of the two founders at hand, it would be very difficult for the company to find someone as visionary, as respected and with the same engineering background to lead the umbrella strategy company. With Sony as a much international company with major branches in Europe and the United States and stocks listed in 23 stock exchanges, the Japanese cultural school strategy is not sufficient. Becoming a mature company, the strategy should also change to more profit orientated. There should also be greater emphasis on market share, especially in Japan where Sony's market is shrinking. Strategy should be aimed at greater control and communication between manager and workers, especially the engineers in the R&D Department. A more planned strategy should be adopted, which should outline the general direction of the company.

Diversification

One direction which is possible is concentrating more on electronic know how in non-consumer business. Currently, the buyer has much more choosing power and competition is fierce (Exhibit 2). The competitors are also able to copy the product in a much shorter time. To create larger profit margins, Sony should concentrate on the business sector and industries, supplying high technology equipment and parts. This would make full use of the R&D Department, the strongest advantage of Sony without waiting for the price cutting and technology adaptation to fit the average consumers needs. This would also make Sony less dependent on coming up with a steady stream of relatively short-lived hit products, and able to use its unique talents in video and semiconductor technology to create its version of the office of the future.

Although the Sony name is often related to expensive, high-profit end of the market, the organization should also expand its product range by offering lower priced, simpler featured products that would compete head on with other copycats. With the lower priced line, Sony can also increase its market shares in both overseas and Japanese markets.

Alliance and Cooperation

Sony should try to become a leader instead of a maverick. The difference is great, the leader, besides a great innovator, should also be a great coordinator. New products, which involve both hardware and software such as the Mavica, should try to achieve industry wide standards. The standard may not be the best or the one created by Sony, but Sony, by pioneering in the field first, would already have a significant head start and the standards is just a way to ensure stability to allow Sony to concentrate on product development and improvement. This is because Sony is not large and strong enough to acquire and provide both software and hardware for one product. They also lack the know-how to the creative software market. Consumers also prefer to have the ability to choose between competitive equipment.

Internally, the different R&D groups should cooperate more. The product line should also be made more compatible with one another which is crucial through the communication between groups and managers, i.e. no more secret projects. Products should be made with higher added value and longer life rather than making frequent model changes. This is also a shift from a manufacturer-orientated mentality to a consumer-orientated mentality, which is a way to save natural resources. The brand-line compatibility also builds brand loyalty for consumers.

In relationship with the other Japanese consumer electronic firms, a more cooperative attitude should also be taken. Just like when Japanese took over the US market through cheap yet quality consumer goods, other Asian countries such as Taiwan and South Korea, with their lower labour cost, pose as great competitors at the lower end of consumer goods. Therefore, the Japanese firms should cooperate in setting up standards in high technology areas in order to reap maximum profits and extend the technological lead-time over their fellow Asian countries.

Cost Cutting

Cost cutting is important because R&D plays an integral part in the success of Sony and cannot be cut drastically although it gobbles up 10% of sales. Therefore, the only way to improve profit margins is to cut cost.

Sony currently has factories in the United States and Japan. Although this is good for relationship of the firm in a foreign firm and offers a chance to pay suppliers with local currencies, Sony is not fully making use of other lower cost areas in the world, especially Asian countries such as Malaysia, Thailand and the Philippines etc. By setting up factories in these countries, Sony can take advantage of their cheap labour and also get a head start in their budding consumer markets.

As mentioned above, products should be refined instead of reinvented so that there would be less set up cost and greater automation could be achieved.

Integration of production, design and marketing

In many ways, designing and developing of a product is separate from the production and marketing. Although there is job rotation, the design stage is backed by intuition and experience rather than market research and analysis. Often, the rational is that it is the marketing personnel's job to find a market for a product after it has been developed instead of the other way round. To cure this phenomenon, R&D should listen more to what the consumer needs and then innovate instead of always creating new markets. With great freedom, the designing team should also take on greater responsibility in making the product fit to the current production pattern and marketing aims. They should also be made more responsible to the profit and lost of the particular product. Empowering these three separate groups create conflict, but it also brings these separate efficient groups together achieving synergy.

Implementation

Internally, strategy should be reviewed beginning with renewing the corporate goals. It should integrate together both the Japanese work ethic and its western counterparts. This is possible, because Sony is a multinational corporation with employees and customers in many different countries. This involves writing the importance of profits and its responsibility to shareholders in the statement. Integration of the company, the designing, production and marketing should be encouraged, with increased communication between each groupand the management acting as liaison and guidance. The management should be providing the organization with specific goals and strategies for the short and long term. These changes are intended to balance business Vs engineering.

Setting up alliances with fellow electronic manufacturers / competitor is crucial to mutual benefit so should be pursued as soon as possible. In areas such as the VTR, Sony has to decide what standard the world is adapting and make decisions to cut off setbacks. For new products such as the Mavica, new standards for the industry should be actively sort after with commitment from other competitors and conventional producers. This is also a change in culture for Sony so top management has to actively push and pursue for this direction.

Cost cutting, with emphasis in making use of lower cost of labour in the Asian developing countries should then be implemented. This could also be seen as a long term strategy. The work force could also be made more flexible. Finally, diversification, with emphasis on making business supplies a major part of Sony's business. This is one of the long term goals in which Sony should thrive to achieve. However, the end product ratio between consumer and business products should be constantly reviewed throughout the process to achieve the optimum mix.

Conclusion

Although other electronic firms are taking market share and profits from Sony by being copycats, the heart of Sony's success, the innovative spirit and quest of excellence and perfection cannot be copied. Sony's main task is to integrate its talent by placing common goals and priority for this increasing competitive market. Sony also has the potential to innovate into a company with international operations as well as culture since it was one of the first Japanese companies to set up a main branch in the United States. With strategy and luck, Sony could become a great firm as it was and will be.

Putra-Design

Selasa, 24 Februari 2009

Torque sensor helps to reduce engine friction..

A torque sensor is helping to reduce engine emissions and improve economy as part of a project to develop an intelligent lubrication system.With engine efficiency under the spotlight like never before, automotive companies are exploring all avenues for improving performance. And because engines have a rotating power output, torque is the key measurement.

Car engines are the bête noire of the environmental lobby. There is no doubt that they are major contributors to carbon build up. But equally they are fundamental to modern life. A true replacement is decades away, so we have to make them as efficient as possible. Engine lubrication systems are essentially dumb.

They have a simple mechanical pump which has been sized to ensure an adequate supply of oil in the worst operating condition. This is typically a hot engine at idle. The pump is thus hugely oversized for most of the rest of the speed range and, as a consequence, nearly 60 per cent of its output is dumped straight back into the sump via the relief valve.

It will also deliver the same amount of oil to every part of the engine regardless of what that system might actually need. The pump is also insensitive to engine load and thus the bearings will receive the same oil supply at a given speed regardless of the load. This is a very inefficient system.In addition the pump forces nearly a ton of oil per hour through the filter, and when the oil is cold this takes a huge amount of energy.

With this in mind a major UK company asked Powertrain Technologies Ltd in Snetterton, Norfolk, to design an intelligent lubrication system and to analyse its effects on engine friction and parasitic losses. They built a highly specialised test rig for the project and, since accuracy in measuring small changes in drive torque reliably and repeatedly was a critical requirement, a key part of the rig is a TorqSense transducer from Sensor Technology.

The engine being tested was a current production diesel and the test bed was configured for motored friction tests with a 6,000rpm 32kW electric motor driving the engine. Andrew Barnes, a director at Powertrain explains: “We completely re-designed the engine lubrication system and installed a bank of five computer controlled oil pumps (to our own design).

Each is capable of supplying individual parts of the engine with oil under conditions unique to that part of the engine and sensitive to the engine operating conditions (for example we can supply the head with oil at pressures different to the block and supply the bearings with more oil when the engine is under high load).”The idea is to completely profile the performance of the engine under various lubrication conditions and to derive optimum configurations of the intelligent systems for best performance.

“Both petrol and Diesel engines run far cleaner than they did 20 or 30 years ago,” says Andrew. “However the need to operate efficiently under a wide range speeds and loads and environmental conditions from -40°C to 40°C remains the Achilles Heel. Intelligent lubrication has the potential to improve performance no end, although quantifying the best configuration is painstaking work.”

He goes on to explain that the torque sensor is critical to the project since the object of the exercise is to measure the effect on friction of a range of different oil supply strategies and oil types. Thus the changes in friction are represented by a change in the motored drive torque of the engine. TorqSense sensors are particularly appropriate for development work because they are wireless.

TorqSense effectively senses and measures the radio frequency (RF) waves generated by two Surface Acoustic Wave devices (SAWs) fixed onto a rotating shaft and converts them to a torque measurement using two tiny SAWs made of ceramic piezoelectric material with frequency resonating combs laid down on their surface. The SAWs are fixed onto the drive shaft at 90degrees to one another. As the torque increases the combs expand or contract proportionally to the torque being applied.

In effect the combs act similarly to strain gauges but instead measure changes in resonant frequency. The adjacent RF pickup emits radio waves towards the SAWs as well as collecting the reflected resonant changes and its this change in frequency of the reflected waves that identifies the applied torque.

Powertrain's research has now progressed to the next stage in which the test rig is forsaken and the engine installed in a car to quantify the effect on fuel economy. “It’s now a matter of driving it under all sorts of conditions on a mixture of test tracks and rolling roads to build up profiles of fuel consumption, says Andrew.

Engineer Live - Putra Design