How Change Auto Cad background color

Normally open auto cad

Step 1: right click the mouse and select the option button

Step 2: option box open. Next go to the display menu and click colors button.

Step 3: choose the color and click apply&close button.

                       (or)

using keyboard and write command,

Step 1- command : op (click enter)

Step 2- option box open. 

Step 3- Next go to the display menu and click colors button.

Step 4- choose the color and click apply&close button.

Using mouse:

Step 1: right click the mouse and select the option button

Step 2: option box open. Next go to the display menu and click colors button.

Step 3: choose the color and click apply&close button 

Using key board:

Step 1- command : op (click enter)

Step 2- option box open. 

Step 3- Next go to the display menu and click colors button.

Step 4- choose the color and click apply&close button.

Anti-lock Brake System

History of anti lock brake system:

     ABS was first developed for aircraft use in 1929 by the French automobile and aircraft pioneer Gabriel Voisin, as threshold braking on airplanes is nearly impossible.

These systems use a flywheel and valve attached to a hydraulic line that feeds the brake cylinders. The flywheel is attached to a drum that runs at the same speed as the wheel. In normal braking, the drum and flywheel should spin at the same speed. However, if a wheel were to slow down, then the drum would do the same, leaving the flywheel spinning at a faster rate. 

      In testing, a 30% improvement in braking performance was noted, because the pilots immediately applied full brakes instead of slowly increasing pressure in order to find the skid point. An additional benefit was the elimination of burned or burst tires.

- In 1972, four wheel drive Triumph 2500 Estates were fitted with Mullard electronic systems as standard. Such cars were very rare however and very few survive today.

-  In 1985 the Ford Scorpio was introduced to European market with a Teves electronic system throughout the range as standard. For this the model was awarded the coveted European Car of the Year Award in 1986.

- In 1988, BMW introduced the first motorcycle with an electronic-hydraulic ABS: the BMW K100. 

- Honda followed suit in 1992 with the launch of its first motorcycle ABS on theST1100 Pan European.

- In 2007, Suzuki launched its GSF1200SA (Bandit) with an ABS. In 2005, Harley-Davidson began offering ABS as an option for police bikes.

Effectiveness:

Braking distance from 80-0 km/h: locked wheels ABS
dry pavement -  45 m 32 m                                                                                    snow         -  53 m 64 m
     ice            - 255 m 404 m

Components:

Speed sensors:

     A speed sensor is used to determine the acceleration or deceleration of the wheel. These sensors use a magnet and a coil of wire to generate a signal. The rotation of the wheel or differential induces a magnetic field around the sensor. The fluctuations of this magnetic field generate a voltage into the sensor. Since the voltage inducted on the sensor is a result of the rotating wheel, this sensor can become inaccurate at slow speeds. The slower rotation of the wheel can cause inaccurate fluctuations in the magnetic field and thus cause inaccurate readings to the controller.

Valves:

     There is a valve in the brake line of each brake controlled by the ABS. On some systems, the valve has three positions:

In position one, the valve is open; pressure from the master cylinder is passed right through to the brake.

    In position two, the valve blocks the line, isolating that brake from the master cylinder. This prevents the pressure from rising further should the driver push the brake pedal harder.

In position three, the valve releases some of the pressure from the brake.

The majority of problems with the valve system occur due to clogged valves. When a valve is clogged it is unable to open, close, or change position. An inoperable valve will prevent the system from modulating the valves and controlling pressure supplied to the brakes.

Pump:

     The pump in the ABS is used to restore the pressure to the hydraulic brakes after the valves have released it. A signal from the controller will release the valve at the detection of wheel slip. After a valve release the pressure supplied from the user, the pump is used to restore a desired amount of pressure to the braking system. The controller will modulate the pumps status in order to provide the desired amount of pressure and reduce slipping.

Controller:

    The controller is an ECU type unit in the car which receives information from each individual wheel speed sensor, in turn if a wheel loses traction the signal is sent to the controller, the controller will then limit the brake force (EBD) and activate the ABS modulator which actuates the braking valves on and off.

Anti Lock Brake ABS Operation:

     The anti-lock brake system or  the ABS  control unit helps to maintain control and directional stability of an automobile  in case of extreme braking circumstances. This is achieved by controlling the rotational  speed of every wheel by metering the brake line pressure at the time of extreme  braking. The system works on most types of road surfaces and decreases the risk  of an accident and severity of an impact. Research has shown that an anti-lock brake  system can decrease the chance of a vehicle accident by 18%. ABS brake systems were  introduced in the late seventies and have enjoyed great technological advances since  that time.

     Not only does ABS provide non-skid functionality but it also supports electronic stability control, brake assist, traction control, etc. Recently, additional sensors  have been added to the system, gyroscopic sensors and steering wheel angle sensors.  Both synchronize to match the direction of the car with the direction of the steering  wheel. The wheel angle sensor also helps the ABS system control the outer wheels  to have a more positive braking effect when compared to the inner wheels on the  curve.

Typical ABS Brake System:

     The ABS assembly is made up of a central electronic unit, four solenoid valves  and two or more electric hydraulic pumps. The function of the electric hydraulic  pump is to supply brake fluid pressure to the braking system by forcing hydraulic  pressure to a reservoir located in the accumulator. The four solenoid pressure valves  control brake fluid pressure for each individual wheel. During an ABS operation  event, one or more of the solenoid valves dump brake line pressure to a particular  wheel allowing it to start turning.

     There are several types of ABS systems; some of the most popular models are based  from the Bosch ABS Actuator (BAA), Nippon-Denso ABS Actuator (NAA) systems. The  basic design and assembly is the same, the Nippon-Denso system has a separate solenoid  relay pack and ABS computer, where as in the Bosch system both the components are  combined. Also, there is an immediate connection between the wheel speed sensors  and the ECU (engine control unit), these systems are connected by the CAN (Controller  Area Network) bus, this system communicates by sending multiple signals to multiple  devices at any given time

     Each wheel has a dedicated wheel speed sensor which sends an electronic signal to the ABS controller, from  this signal the rotational speed of the wheel can be determined. The location of  wheel speed sensor may vary, on most vehicles the front sensor is made into the  steering knuckle, near the front wheel hub  or outer CV joint.  In the rear of the vehicle the sensor rings are bolted to the rear driver assembly  on the ring gear or attached to the outer axle flange on each side. Some even use  the vehicles speedometer sensor VSS (vehicle speed sensor) to read rear wheel speed.

Common Problems and Fixes:

     Today's brake systems are reliable and easy to maintain, most systems are designed for easy service and brake pad replacement. If the brake pedal becomes hard to push, there can be a possibility of a broken vacuum supply line or a failed power brake booster. It is also very important to use the correct type of brake  fluid; otherwise the brake system can malfunction. This can lead to problems such  as spongy feeling pedal and the brake pedal travel becoming excessive. Only the  highest quality brake fluid must be used in a brake system and must never be reused  and must always be discarded immediately after the fluid storage container is opened  to avoid moisture contamination. When adding brake fluid to the master cylinder  care must be taken make sure brake fluid is not spilled on the paint of the car,  brake fluid is very corrosive and will destroy the paint.

     Squealing brakes is an indication of a problem with the brake system. Most of  the time a squealing noise can be a warning that the brake pads are worn down and  need to be replaced. Other causes can be overheated brake pads or rotors. Sometimes  rust can get impregnated on the brake lining material and cause grumbling or squeaking  noises. When cleaning brake components prior to service precautions must be taken.  Most brake systems contain microscopic fibers that are extremely hazardous to your  health. While cleaning with brake system cleaner there is an increased chance of  inhaling these fibers that accumulate on the brake components. Cleaning should be  done in a well ventilated area, use an air filter respirator if possible for best  results.

      When the ABS system detects a problem a fault code is stored in the ABS system control unit. When an error occurs the ABS warning light located on the dashboard flashes or stays on steadily. The ABS computer stores a diagnostic code until the malfunction has been repaired. To retrieve ABS trouble codes on older vehicles can be tricky because of the variation  of retrieval methods; in this case a car repair manual is needed. On newer vehicles a diagnostic information connector  is located under the dash on the driver's side; a trouble code scanner can be attached to retrieve ABS codes similar to engine  trouble codes.

     After the problem has been repaired codes should erase automatically with no procedure from the scan tool in most cases. (Real time system) when the vehicle  has been moved about 6 feet and the brake pedal has been pressed for five seconds  the codes should clear. When repairs have been completed the ABS, MIL (malfunction indicator lamp) should not be illuminated, if the ABS light remains on there is  still a problem, re-scan the ABS computer for further repairs.

History of BMW

History:

BMW:  Bayerische Motoren Werke (OR) English - Bavarian Motor Works

The Founder of BMW  - Karl Friedrich Rapp

   This is a German automobile company. Motorcycle and engine manufacturing company founded in 1916. BMW is headquartered in Munich, Bavaria, Germany.  In 2012, the BMW Group produced 1,845,186 automobiles and 117,109 motorcycles across all of its brands. BMW is part of the "German Big 3" luxury automakers, along with Audi and Mercedes-Benz, which are the three best-selling luxury automakers in the world.

   BMW AG is a German company and one of the leading manufacturers of automobiles and motorcycles in the world. Founded in 1916 and based in Munich (state capital of Bavaria), Germany, BMW is also the parent company of the MINI and Rolls-Royce car brands. BMW AG stands for Bayerische Motoren Werke Aktiengesellschaft, or Bavarian Motor Works.

1922 - After the end of the war, railway brakes and inboard engines were manufactured following the prohibition on the production of aero-engines. After the company was sold to Knorr Bremse AG in 1920, financier Camillo Castiglioni acquired engine production along with the workforce and production facilities. That same year the company relocated to the production facilities of BFW at Munich’s Oberwiesenfeld airfield. 

1923 - BMW announced its first motorcycle, the R 32, in 1923. Until then the company had only supplied engines rather than complete vehicles. The basic concept of the original BMW Motorrad model – a boxer engine with longitudinally positioned cylinders and shaft drive – is so sound, that it continues to be employed in the company’s motorcycles to this day.

1934 - Starting in 1933, aircraft construction in Germany received substantial financial support from the government. In 1934, BMW AG hived off its aero-engine division to BMW Flugmotorenbau GmbH. Two years later Flugmotorenfabrik Eisenach GmbH was established jointly by the AG (public limited company) and the GmbH (private limited company) and the letters BMW were included in the name in 1939

1941 - During the Second World War, BMW was classified as a German armaments and war materials manufacturer, and devoted its resources almost exclusively to building aircraft engines for the German Air Force. Other plants were opened in addition to those in Munich and Eisenach.

1942 - BMW takes on its first foreign workers in 1940, employing them on the factory floor. From 1942, convicts, Eastern European prisoners of war, and predominantly Western European forced labourers are made to work at BMW alongside concentration camp prisoners. As in the majority of German industries, the company’s management has a technocratic approach and is focused on efficiency. The use of forced labour is tacitly approved and accepted. During the Third Reich, forced labourers must work in deeply distressing conditions. Today, BMW is painfully aware of the great human suffering caused by this, and deeply regrets the fate of the forced labourers.

1948 - The first BMW vehicle to take to the road after 1945 was the R 24 motorcycle, introduced in March 1948; it was a developed version of the pre-war R 23 model. Shortages of materials and machinery delayed series production until December 1948, but the sales success of the R 24 then exceeded all expectations, and 9,144 were sold in 1949 alone.

1951 - BMW's first post-war automobile was the 501, built from 1952 onwards. A large saloon capable of seating up to six people, it was powered by a developed version of the six-cylinder engine used in the pre-war BMW 326. As a luxury car, the BMW 501 was not a commercial success, but it none the less restored BMW's status as a manufacturer of high-quality, technically exciting cars.

1961 - BMW exhibited the 1500 model at the 1961 German Motor Show, and with it penetrated a gap in the market. This was the model that re-established BMW as a successful, modern carmaker. The design of the four-door touring car immediately generates excitement, and orders far exceed production capacities. By 1963, the company is able to record a profit once more.

1967 - In the mid-1960s, the BMW Munich plant reached the limit of its capacity. BMW initially drew up plans for the construction of new facilities but then purchased crisis-ridden automotive company Hans Glas GmbH together with its locations in Dingolfing and Landshut. Both sites were restructured and the biggest BMW plant in the world was created at Dingolfing in the subsequent decades.

1972 - In 1972, BMW brings together all of its various motor racing activities within a new wholly owned subsidiary – BMW Motorsport GmbH. With the BMW Motorsport GmbH , BMW lays the foundations for BMW M GmbH.

1973 - Starting in 1970, BMW began to build an administrative tower block in the north of Munich. Its unusual shape soon led to it being described as the "four-cylinder building", and it is now a notable landmark in the city's architecture. The BMW Museum was installed next to it in a bowl-shaped building that has remained unique of its kind. The new building complex was officially opened on 18 May 1973.

1973 - Sales Director Bob Lutz initiated a policy at BMW to take sales responsibility for all the major markets from the current importers from 1973 onwards. This responsibility was gradually transferred to dedicated subsidiary companies. France was the first country where BMW established its own sales company in 1973.

1987 - The Munich BMW plant was now only building the 3 Series and a decision to build a new plant in Regensburg was taken on 26 November 1982. This was intended to meet the growing demand for this model and relieve the pressure on the BMW plant in Munich. The foundation stone was laid in the neighbouring community of Obertraubling in 1984 and the Regensburg plant was opened in 1987.

1990 - In 1986, BMW brings together all research and development work under one roof at the Forschungs- und Innovationszentrum (Research and Innovation Centre, or FIZ) in Munich. It is the first automotive manufacturer to establish such an institution, which houses around 7,000 scientists, engineers, designers, managers and technicians, working together as part of an integrated team. The facility was officially opened on 27 April 1990. In 2004, the FIZ is expanded with the Projekthaus building.

1994 - BMW decided to build an automobile production facility in the USA in 1989. This move highlighted its position as a global player. The plant in Spartanburg (South Carolina) was specially designed for production of the BMW Z3 Roadster and opened in 1994. The Z3 was exported from Spartanburg all over the world.

1998 - In July 1998, BMW acquires a piece of automotive history. Following long negotiations, the company obtains the brand and naming rights for Rolls-Royce motor cars from Rolls-Royce plc. Rolls-Royce is held entirely by Volkswagen until the end of 2002, when BMW takes on full responsibility for Rolls-Royce Motor Cars, along with all rights. The new Rolls-Royce plant and a new company headquarters are then built in Goodwood, in southern England. This is the sixth facility constructed since 1904.

2000 - The realignment of Group strategy in 2000 strengthened the BMW Group and made it fit for the future. From the year 2000, the company resolved to focus solely on the premium segment in the international automobile market with the brands BMW, MINI and Rolls-Royce Motor Cars. The entire model range was expanded by new series and versions. Alongside the Sports Activity Vehicles in the X Series, the company also developed the first BMW in the premium segment of the compact class with the BMW 1 Series from 2004.

2001 - The MINI Hatch made a start in 2001 – and by 2011 the MINI family had grown to six model versions, with the MINI Convertible, MINI Clubman, MINI Countryman, MINI Coupé and MINI Roadster.

2007 - The BMW Welt opened on the site to the west of the BMW Tower in October 2007. This forward-looking building designed by Viennese architect’s practice Coop Himmelb(l)au forms the portal for the brand and the delivery centre for BMW automobiles. BMW Welt, the plant tour and the BMW Museum create the ensemble of experience presenting the history, reality and vision of the BMW brand.

BMW logo History:

BMW Logo

   From 1917, each of the company’s products proudly displays the BMW emblem, which incorporates the state colours of Bavaria. At the end of the 1920s, the emblem makes its first appearance in the company’s advertising as a rotating propeller – taking a form that will be used as the logo long into the future.

   The BMW logo consists of a thick black ring encircled by a silver lining. The letters ‘BMW’ are inscribed in a non-serif font in the top half of the black ring.  The gap within the ring is divided into four equal alternative blue and white quarters. The BMW logo, commonly known as "roundel", was created and registered in 1917. The created logo design is remarkably simple and projects an identity that is smart, clear, sporty and image-conscious. It is one of the most distinctive logo designs in the world, speaking highly of a brand-led company. The 1929 Dixi was the first vehicle to carry the famous BMW logo. The BMW logo has been altered very rarely and minutely and has maintained its original look throughout the company's history. Here are some of the logos that have been used since 1917.

   One version of the ‘sky blue and white checker box’ BMW logo myth connects it with a shining silver/white rotating propeller that the engineers of BMW were working on. The other relates the BMW logo to Bavaria as the place where the products of the company are manufactured and with the national colors of Bavaria.

Engine:

   Digital Motor Electronics (DME) is a microprocessor-based system that controls the ignition, the fuel injection, the oxygen sensor and numerous ancillary functions. DME provides raw data to an on-board computer that uses an alphanumeric display to provide you with information such as the average fuel consumption, the distance you can still cover with fuel in the tank, an average speed, outside temperature and more.

DME operates by continually monitoring such factors as engine temperature, speed, intake airflow, exhaust gas composition, and even the altitude. DME then literally fine-tunes the engine hundreds of times a second to provide maximum performance and efficiency. DME has a fail-safe program in the event of certain electrical faults. Current DME versions also have on-board diagnostics (OBD).

How it's working?

   The two main tasks DME has to perform are (1) injecting the right amount of fuel and (2) providing a spark at the correct time. In order to do this, the system needs to know things about the engine's current state. DME can track dozens of different sensors, but every system needs to know three basic things: 

1.     how much air is coming in

2.     the position of the throttle, and 

3.     how fast the engine is running.

Anti-lock Brake System (ABS):

BMW ABS Break system

   Even when applying the full force of braking power, the vehicle remains under your complete control thanks to the Anti-lock Brake System. It uses precise regulation of the braking pressure on the individual wheels to ensure that the vehicle can always be steered easily. ABS prevents the wheels from locking, regardless of the road surface’s friction coefficient and the applied brake pressure.

   Unexpected obstacles on the lane ahead, a pedestrian suddenly stepping on the road, an abrupt change in traffic or driving conditions: there are many moments when a driver reacts quickly with intense application of the brakes.
At these moments, ABS assists the driver by preventing the wheels from completely locking and applying the optimum braking pressure to the individual wheels, thus ensuring the vehicle can still be steered and shortening braking distances on slippery surfaces. The driver may sense that ABS is functioning by the slight pulsing movement of the brake pedal.
   ABS regulates the force of brake pressure on each wheel to provide both maximum braking effectiveness while still allowing the wheel to continue rotating in a controlled way. If the system recognizes that a wheel is locked or almost locked, it momentarily reduces the brake force, letting the wheel rotate, regain traction and thus allowing the vehicle to be steered.
   ABS then reapplies the brake pressure. Thanks to modern electronics and intelligent control algorithms, ABS does this with such remarkable speed and smoothness that both braking and steering are simultaneously effective throughout the braking process - and the driver stays in control of the vehicle.

Feature:

   We can expect coupe, convertible and M3 variants of the new 3 Series in the next couple of years, most likely in that order. In 2014, we will possibly see the i3, BMW’s full electric city car, followed a year or so later by the i8, a sporty plug-in hybrid. Both use lithium-ion batteries and share materials technology that includes a carbon-fibre passenger cell and aluminium chassis.

BMW I3

A Brief History of Robotics

       Science fiction has no doubt contributed to the development of robotics, by planting ideas in the minds of young people who might embark on careers in robotics and by creating awareness among the public about this technology. we should also identify certain technological developments over the years that have contributed to the substance of robotics. this table presents a chronological listing which summarizes the main early historical developments in the technology of robotics.

        Some of the early developments in the field of automata deserve mention although not all of them deal directly with robotics. in the seventeenth and eighteenth centuries, there were a number of ingenious mechanical devices that had some of the features of robots. JACQUES DE VAUCANSON built several human-sized musicians in the mid-1700s. essentially, these were mechanical robots designed for a specific purpose: 

entertainment. in 1805, HENRI MAILLARDET constructed a mechanical doll which was capable of drawing pictures. a series of cams were used as the "program" to guide the device in the process of writing and drawing. MAILLARDET'S writing doll is on display in the FRANKLIN institute in PHILADELPHIA, PENNNSYLVANIA. these mechanical creations of human form must be regarded as isolated inventions reflecting the genius of men who were way ahead of their time. there were other mechanical inventions during directed at the business of textile production. these included Hargreaves spinning  jenny(1770), Crompton's mule spinner(1779), Cartwright's power loom(1785), the jacquard loom (1801), and others.  

date	development
mid-1700's	j.de vaucanson built several human-sized mechanical dolls that played music.
1801	j. jacquard invented the jacquard loom, a programmable machine for weaving threads or yarn into cloth.
1805	H.Maillardet constructed a mechanical doll capable of drawing pictures.
1946	American inventor G.C. Devol developed a controller device that could record electrical signals magnetically and play them back to operate a mechanical machine U.S.pstent issued in 1952.
1951	Development work on teleoperators for handling radioactive materials. related U.S. patents issued to Goeertz (1954) and bergsland (1958)
1952	prototype numerical control machine demonstrated at the massachusetts institute of technology after several years of development. pan programming language and released in 1961,
1954	british inventor C.W.kenward applied for patenr tor robot design. British patent issued in 1957.
1954	G.C.devol develops designs for "programmed article transfer" U.S.patent issued tor design on 1961.
1959	first commercial robot introduced by planet corporation. it was controlled by limit switches and cams.
1960	first "unimate" robot introduced, based on devol's programmed  ankle transfer. it used numerical control principles for manipulator control and was a hydraulic drive robot.
1961	unimate robot installed at ford motor company for tending a die casting machine
1966	Trallfa, a Norwegian firm, built and installed a spray painting robot.
1968	A mobile robot named shakey developed at SRI (Stanford research institute). it was equipped with a variety of sensors, including a vision camera and touch sensors, and can move on the floor.
1971	The "Stanford arm" a small electrically powered robot arm, developed at Stanford university.
1973	first computer- type robot programming language developed at SRI got research called WAVE followed by the languages AL in 1974. the two  languages were subsequently developed into the commercial VAL. languages for unimation by Victor Scheinman And Bruce Simanon.
1974	ASEA introduced the all-electric drive IRb6 robot.
1974	Kawasaki, under unimation license, installed arc-welding operation for motorcycle frames.
1974	Cincinnati Milacron introduced the T3 robot with computer control.
1975	Olivetti "sigma" robot used in assembly operation- one of the very first assembly applications of robotics.
1976	Renite center compliance device for part insertion in assembly developed at Charles stark draper labs in united states.
1978	PUMA (programmable universal machine for assembly) robot introduced for assembly by unimation, based on designs from a general motors study.
1978	Cincinnati Milacron T3 robot adapted and programmed to perform drilling and routing operations on aircraft components, under Air force ICAM (Integrated Computer Aided Manufacturing ) sponsorship.
1979	development of SCARA type robot at yamanashi university in Japan for assembly. several commercial SCARA robots introduced around 1981.
1980	Bin-picking robotic system demonstrated at university of Rhode island. using machine vision, the system was capable of picking parts in random orientations and positions out of a bin.
1981	a direct-drive robot developed at Carnegie-Mellon university. it used electric motors located at the manipulator joints without the usual mechanical transmission linkages used on most robots.
1982	IBM introduces the RS-1 robot for assembly, based on several years of in- house development. it is a box- frame robot, using an arm consisting of three orthogonal slides. the robot language AML, developed by IBM, also introduced to program the RS-1.
1983	report issued on research at Westinghouse corp. under national science foundation sponsorship on "adaptable-programmable assembly system" (APAS),a pilot project for a flexible automated assembly line using wools.
1984	several off-line programming systems demonstrated at the robots 8 show. typical operation of these systems allowed the robot program 10 he developed using interactive graphics on a personal computer and then downloaded to the robot.
1990's	robot development diversified into walking robots at MIT, Honda, etc., rehabilitation robots for health care , as well as robots for defence and space applications.
2000's	micro and nano robots using smart materials, unmanned Ariel vehicles and underwater robotics.