I. Mechanical design of the elevatorA. Hydraulic elevatorThe hydraulic system has four main parts: A tank (the fluid reservoir) A pump, powered by an electric motor A valve between the cylinder and the reservoir Cylinder is connected to a fluid pumping system.In the conventional system, the entire cylinder structure must be buried below the bottom elevator stop. This means you have to dig deeper as you build higher. This is an expensive project with buildings over a few stories tall. In this project, we will use the telescopic piston (it can lengthen and shorten) to save space (see fig.1)

Figure 1Principle operationThe car of a hydraulic elevator is lifted from below by a hydraulic ram. A hydraulic ram is a long piston that is driven into or out of a hollow cylinder by pressure in a hydraulic fluid. The hydraulic fluid, usually oil or water, exerts a force on any surface it touches, including the base of the piston. If the pressure in the hydraulic fluid is high enough, the force it exerts on the base of the piston will exceed the weight of the piston and elevator car and they will accelerate upward. But as the piston rises, the hydraulic fluid has more space to fill and its pressure drops. To keep the piston moving upward, something must continuously add high-pressure hydraulic fluid to the cylinder, that is usually an electrically powered pump. This pump draws low-pressure hydraulic fluid from a reservoir and pumps it into the cylinder. The pump does work on the fluid and this work is what lifts the elevator car. When the elevator car has reached the proper height, the pump stops and the piston rests on the high-pressure hydraulic fluid beneath it. As long as the amount of fluid in the cylinder doesnt change, the piston and car will stay where they are as the passengers get on and off. To let the car descend, the elevator opens a valve and permits the high-pressure hydraulic fluid to return to the low-pressure reservoir. The fluid naturally accelerates toward the lower pressure and the cylinder begins to empty. The car descends. However, the fluid in the cylinder has considerable pressure potential energy and that energy must go somewhere. As it flows through the valve, the fluid accelerates and it rushes into the reservoir at high speed. But its kinetic energy soon becomes thermal energy as the fluid swirls around randomly. When the swirling has stopped, the fluid in the reservoir will be warmer than it was before the elevator made its trip up and down. Because it lifts the car from below like a jackscrew, the hydraulic elevator is naturally very safe. Even if the cylinder springs a leak, the hydraulic fluid will probably not flow out of the cylinder fast enough for the car to descend at a dangerous speed. But unlike a jackscrew, a hydraulic ram encounters very little friction and wear, so its piston can move in or out of the cylinder rapidly. As a result, the car of a hydraulic elevator can be lifted as fast as the pump can deliver high-pressure hydraulic fluid. Of course, the pump has to do a great deal of work on that fluid in a short time, so it must be very powerful. Nonetheless, the speed of a hydraulic elevator is limited only by the power of the pump and the comfort of the passengers.

1. Car frame (sling) and platformThe car frame forms the supporting steel structure of the car. It consists of three main parts: the crosshead beam, two vertical uprights, called stiles and the safety plank. The car sling is completed by bolting, riveting or welding the stiles to the crosshead at their upper end and to the safety plank at the bottom. It must be guided on each guide rail by upper and lower slide guide shoes attached to the frame.The crosshead beam is the upper member of the car slingThe stiles must have sufficient stiffness to carry an eccentric load which tends to bend the stiles and distort the frame.The safety plank forms the base of the sling and supports the car platform, on which passengers and/or load rest during the travel. The platform has more functions as a support for various other elevator equipment. Junction boxes are supported either from steel car frame members or from the underside of the platform. All electrical connections to the car are established at this junction.Toe guards are also attached to the car platform. They must be effectively flush with the hoist way edges of the sills and must span the entire width of the hoist way door opening. They are made of steel. They have a straight vertical face, extending below the floor surface of the platform.Platform isolation is rubber or other vibration absorbing material which reduces the transmission of vibration and noise to the platform. These pads are often replaced when modernizing as new isolation is more resilient and helps to reduce vibration and improve the comfort of the ride for passengers.Brace rod is a rod extending from the elevator platform framing to another part of the elevator car frame or sling for the purpose of supporting the platform or holding it securely in position. Brace robs are supports for the outer corners of the platform, each of which tie to upper portions of the stile.Car enclosure is mounted onto the platform and as a rule, it is made up of a series of panels. The material for car enclosures and car linings must be either metal, fire-retardant-treated wood, or some equally fire-retardant approved materials.

2. Door Mechanism

Figure 3: Doors Mechanism1. Motor 2. Pulley 3. Belt 4. Guide way 5. Door panel

The automatic doors at grocery stores and office buildings are mainly there for convenience and as an aid for handicapped people. The automatic doors in an elevator, on the other hand, are absolutely essential. They are there to keep people from falling down an open shaft. Elevators use two different sets of doors: doors on the cars and doors opening into the elevator shaft. The doors on the cars are operated by an electric motor, which is hooked up to the elevator computer. You can see how a typical door-opener system works in Figure 3. The electric motor turns, the motion is transmitted to the pulley, then to two door panels which are mounted on the belt through the pulley-belt mechanism. Two panels will slide back and forth in two opposite direction on a metal rail. The door is made of two sheets of steel will be mounted on the two panels. The computer turns the motor to open the doors when the car arrives at a floor and close the doors before the car starts moving again. Many elevators have a motion sensor system that keeps the doors from closing if somebody is between them. The car doors have a clutch mechanism that unlocks the outer doors at each floor and pulls them open. In this way, the outer doors will only open if there is a car at that floor (or if they are forced open). This keeps the outer doors from opening up into an empty elevator shaft.

3. Hydraulic SystemTelescopic CylindersThe great advantage of telescopic cylinders over conventional rod-type cylinders is their ability to provide an exceptionally long stroke from a compact initial package. The collapsed length of typical telescopic cylinders varies between 20% to 40% of their extended length. Thus, when mounting space is limited and the application needs a long stroke, a telescopic cylinder is a natural solution.Telescopic hydraulic cylinders are relatively simple devices, but their successful application requires an understanding of their construction. Knowledge of how telescopic cylinders work and which special application criteria to consider will help you design them safely and economically into your equipment.

Main and StagesAs the name suggests, telescopic cylinders are constructed like a telescope. Sections of DOM (drawn over mandrel) steel tubing with successively smaller diameters nest inside each other. The largest diameter section is called the main or barrel; the smaller-diameter sections that move are called stages. The smallest stage is also called the plunger. The maximum practical number of moving stages is generally six. Theoretically, cylinders with more stages could be designed but their stability would be compromised.Telescopic cylinders normally extend from the largest stage to the smallest. The pressure depends on the magnitude of the load and contact area. This means that the largest stage with all the smaller stages nested inside it will move first, and will complete its stroke before the next stage begins to move. This procedure will continue for each stage until the smallest-diameter stage is fully extended. Conversely, when retracting, the smallest diameter stage will retract fully before the next stage starts to move. This continues until all stages are nested back in the mainTo extend, the high pressure oil is directed by the control valve into port A. The oil passes through the transfer tube in the rod to the base of the cylinder.To retract: with no oil pumps, the weight of the body pushes oil in the cylinders to the tank and cylinder will be shorten.

Basic Cylinder TypesAs with conventional cylinders, the two basic types of telescopic hydraulic cylinders are single-acting and double-acting.Single-acting telescoping cylinders extend under hydraulic pressure and rely on gravity or some external mechanical force for retraction. Single-acting cylinders are used in applications where some form of load is always on the cylinders. Pressurized oil extends the telescopic cylinder to raise one end of the dump body and expel its load.When pressure is released, the weight of the dump body forces oil out of the cylinder and it retracts.Double-acting telescopic cylinders are powered hydraulically in both directions. They can be used in applications where neither gravity nor external force is available. They are well suited to non-critical positioning applications requiring out-and-back movement of a substantial load. A classic application is the packer-ejector cylinder in refuse vehicles and transfer trailers. The horizontally-mounted cylinder pushes a platen to compress the load, then must retract with the platen so that more material can be added. Gravity cannot assist, so a double-acting cylinder is used.In our project we just consider single-acting telescopic.

Bearings and SealsEach stage is supported within each successively larger stage by at least two bearings. One is at the bottom outside diameter or piston end of the stage, and the other is at the top internal diameter or packing section of the next larger stage. The distance between these two bearings determines the degree by which one stage overlaps the next. Generally, this distance or overlap must increase as overall stroke increases in order to resist deflection caused by the weight of extended stages and the load.

There are several designs for sealing telescopic cylinders.One of the most common is the use of several hinged chevron 'vee' seals and/or one-piece, multiple-lip seals with hinged lips moulded in place. These seals are held in place by a stop ring or snap ring and packing nut and they use guide bearings on the sleeve piston. The internal diameter of each stage is sealed against the outer diameter of the next smaller stage nested inside it. The style and positioning of these seals varies among cylinder manufactures. The style of seal also depends on its particular function. Zero-leakage, multiple-lip soft seals are usually found in the internal diameter at the packing section of the main and moving stages. Low-leakage hard seals are found on the piston end of double-acting telescopic cylinders. These piston seals allow the cylinder to retract under pressure.

Principle diagram of the hydraulic system:

1. Reservoir 2. Filter 3,4. Pump 5. Relief valve 6. Pressure gauge7. Distribution valve8. Cylinder9. Check valve10. Flow regulating valve

4. Calculation and design of the cylindera. Principle :

Pascal's Laws relates to pressures in fluids - liquid or gaseous state: if the weight of a fluid is neglected the pressure throughout an enclosed volume will be the same the static pressure in a fluid acts equally in all directions the static pressure acts at right angles to any surface in contact with the fluidb. Requirements Load : 1500kg. Fluid pressure: 6 Mpa Single acting cylinder Stroke length: 12m. Stroke velocity: 1.5m/sc. Length of the cylinder:The system is used for 4-story buildingThen the stroke length is: 3x4m=12m.We use the telescopic cylinder with 6 stages, the length of each stage is 2m.d. Diameter of the cylinder:From the formula: F=A.P F: Force acting on the piston, F = 15000N P: Fluid pressure, P = 6MPa = 6*106 N/m2 A: Working areaThen:

A== =

A=Then the inner diameter of the plunger(the smallest stage):

D===0.056mWe also have: The thickness of the wall of the cylinder: t = 5mm (for all stages) The width of the shoulder of the cylinder: s = 5mm (for all stages) The width of slits between the wall of stages: b = 1mm

From that we can calculate the diameter of other stages.

e. Structure: The plunger:

Connection between stages:

The barrel:

Between stages we use 3 seals: 1 PSP seal and 2 V-packing seals

5. Calculation and selection of pump : The formula for the capacity of the pump: N = (1) Where: N: pump capacity

: volumetric efficiency =0.9

: mechanical efficiency =0.96 P: working pressure P=6Mpa=60bar

Qe: efficient flow rate of the pump, Qe= .QQ: theoretical flow rate Q= V*A A: the area of of the working surface A= =0.0025The stroke velocity: V=1,5m/s Q=0.0025. 1,5=3,75.10-3(m3/s)=3.75(litres/s)Then N= = 0.39 (kW)We choose pump with capacity of: N= 400WFlow rate of the pump : Q=3,75 .10-3(m3/s)

6. Valve selection : a. Relief valve:The relief valve is a type of valve used to control or limit the pressure in a system or vessel which can build up by a process upset, instrument or equipment failure. It opens proportionally as the increasing pressure overcomes the spring pressure, prevent overloading. Valve pressure 6 Mpa Height h=2d Diameter of the pipe d=20mm Then h=40mm

Diameter slit: =0.1mm

Combination of ball valve and piston valve

b. Distribution valve : Distribution valve 5/3( 5 ways 3 positions)Position 1: Sliding block go downPosition 2: Sliding block keep stillPosition 3: Sliding block go upChoose valve with the inner diameter of the pipe is: d = 20mm Then we have the other technical parameters:Qmax = 100 l/phL = 160 mmD = 25 mm. (sliding block diameter).

= 27 mm. (stroke length)

= 0,4 bar.Valve control:To control the position of the sliding block, we use controlling top (electromagnetic control)

Structure of the controlling top of the distribution valveSpring (1) and bearing (2) hold the position of the sliding block at mid-point. Pin (3) press against the axis of the magnets core, the tolerance of the pin to the hole is about 512 m.

c. Flow regulating valve:It is used to control the fluid flow, which helps controlling the speed of the actuators.We set up the valve near the reservoir. Although it then doesnt help decrease the load for the system, but the response is quick. The valve also has the function of a check valve, create a certain pressure on the output of the cylinder, so that it can move smoothly.We choose the adjustable valve, and it is axial adjusting.

Characteristic of the valve

d. Check valve : one-way valves, which normally allows fluid to flow through it in only one direction. allowing an accumulator to charge and maintain its pressure after the machine is turned off, for example. Prevent the fluid from boiling Prevent changing the flow direction. Control the flow Protect the mechanisms

7. Reservoir : a. Function: Holds excess hydraulic fluid to accommodate volume changes from: cylinder extension and contraction, temperature driven expansion and contraction, and leaks. Aid in separation of air from the fluid and also work as a heat accumulator to cover losses in the system when peak power is used. Maintain the temperature of fluid at allowable range.

b. Figure and dimension:Figure: Deep and narrow are better than shallow and wide because the fluid level could be higher and prevent it from whirling.Dimension: Vmin=3Q

c. Structure:Baffle with the height about 2/3 the height of the fluid, with two functions: Prevent the return fluid from going directly to the pump. Prevent the fluid from splashing.

The lid of the reservoir has the vent with filter to prevent the dirts.Choose water cooling:

8. FiltersFilter the dirt and metal particles which continually produced by mechanical components. They need to be removed along with other contaminants.Unrefined filter and fine filter: Unrefined filter: Metal net filter purity 0,08-0,1 mm placed before the pump Fine filter: Paper filter, purity 4-5, placed after the pump.Choose the filters with assisting valve that is closed at normal flow rate. When the flow rate is too high or the filter is clogging, the valve is opened and the fluid can go directly through the valve without filtering.

9. Pipes: Steel C45. Depend on the height the system and disposition of reservoir, we can determine the length of pipes.Inner diameter of the pipe: d = 20 mm.Flow rate : Q = 3.75 (l/s).

Pressure loss: = 0,16 bar.

Steel C45: = 400-500 MPa.Allowable velocity of fluid: v = 5-6 m/s.

10. Fluid:Fluid in hydraulic system is the energy transferring environment. It also functions as lubricant and cooling. We chose SAE 10W-30.

Working range: C to C Various additives to improve lubricity.

B. Traction elevators

1

1. Equipment installed in machine cabinet+ Lifting structureInstalled in the engine wiring lift lifting generate traction and movement of the counterweight.Elevation mechanism includes the following components: pull cable parts (pulleys), reduce speed box, electromagnetic brake and drive motor. All parts are mounted on steel base. In the elevator often use two lifting systems:- Lifting with speed box- Lifting without speed boxLifting without speed boxes are often used in high speed lifts.+ Electric cabinet: the circuit breaker panel assembly, fuses, switches and intermediated relay.Division speed limit part works in collaboration with brake insurance cable to limit the speed movement of the lift

2. Equipment installed in machine cabinet+ Lifting structureInstalled in the engine wiring lift lifting generate traction and movement of the counterweight.Elevation mechanism includes the following components: pull cable parts (pulleys), reduce speed box, electromagnetic brake and drive motor. All parts are mounted on steel base. In the elevator often use two lifting systems:- Lifting with speed box- Lifting without speed boxLifting without speed boxes are often used in high speed lifts.+ Electric cabinet: the circuit breaker panel assembly, fuses, switches and intermediated relay.Division speed limit part works in collaboration with brake insurance cable to limit the speed movement of the lift

a) Withspeedbox;b) Without speed box1.Drive motor2.Electromagneticbrake, 3.Speedbox4.Pull the cablepart

3. Cabin and other related equipmentCabin is part of the elevator load bearing structure. Cabin must have the ability to disassemble it into small parts. About structure, cabin consists of 2 parts: bearing structures (the frame cabin) and the wall covering, ceiling and floor form frame. Over the frame cabin is the guide block, cabin suspension system and brake handles insurance, the system shut down and open structure. In addition, the elevator cabin seats must meet the information requirements wind, temperature and light.

4. Cab suspensionBecause cabin and counterweight are suspended by many separate strands so it requires a suspension to ensure that the separate strands improve the same. In tension case, tensile strength cable will be overloaded even without tension, cable pulley grooves will slide on a very dangerous friction. In addition, due to fiber tension so slack fiber cable on the pulley grooves are worn friction will not same. So that why the suspension system must be equipped with electric contact of the safety circuit breaker to stop the elevator when a in the excess cable slack to allow the ladder to prevent disasters. At this time the elevator can only work when adjusting tension of the cable as the other. The cabin suspension with beams installed on the frame will stand in the cabin bearing system.

5. Guide rails Guide rails were installed along the ladder to lead well and for instructions for cabin moves along well. Guide rails will ensure the cabin always located in the well and will not be moved horizontal during movement. Additionally guide rails also have the stiffness enough for the weight of the cabin and the passengers rest on cabin. The guide rails have bars so when the load brake they will make the insurance (in case of broken cable or cabin goes down at a rate higher than the value allowed).

6. CounterweightCounterweight is the part played a key role in balancing system of the elevator. For the elevators height is not large, people choose counterweight so that its weight equals the weight of cabin plus some weight of its passenger. When the elevators weight increase, the weight of the lifting cable and power cable is considerable so people use chain to compensate the weight of the lifting cables Counter weight can be determined by the formula:m=C + eQIn thatC: Weight cabinQ: The nominal load of the elevatore: Coefficient balanceIf the weight of the counterweight balance perfectly equal with the cabin and payload weight lifting (e = 1) then when raise or lower cabin with fully loaded, the engine's lifting is to overcome friction and inertia force, but the cabin does not load the engine must overcome more resistance is equal to the nominal lifting capacity Q to lower cabin (or lift counterweight). So for that reason people choose counterweight to balance e coefficients so that the force needed to lift the cabin filled with passengers will lower the cabin at no load.

7. Cabin door and floor doorCabin door and the floor door have a very important role in ensuring safe and major damage to elevator quality, productivity of the elevator. The floor and cabin door system is designed so that when you stop at any level, only the engine and open the lift mechanical systems association affiliated with the lift door. In the same way when the system closes the link will not impact and the elevator will move the other floor.

8. The winch systemDepending on the diagram that the winch drive is located in the engine room driving or located above, below or next to the elevator well. The winch system has two kinds: electric actuator including the gearbox and those without the gearbox. For greater speed elevators people use the winch system that do not use the hoisting gear box.

9. Mechanical safety deviceSafety equipment in the elevator will do the job of keeping safety for the elevator and passengers in the event of incidents such as broken cables, cable pulley sliding on a track friction, lower the cabin with racket speed than the permitted value

Insurance brake type pliers

1. Navigation bar 2. Grip 3. Cables associated with the engine speed limit 4. Wheel screw 5. Wedge10. Limit switch

A limit switch is an electrical switch designed to cut off power to a machine at the extent of its possible movement.A limit switch placed on an elevator would shut off the power if the car goes higher or lower than it is supposed to go within safety measures. Keeping an elevator from passing a certain point protects not only the occupants but also the motors and pulleys that drive the elevation of the car. Before a machine is produced and used, a limit switch must be included in the design to satisfy safety regulations.

II. Electronic design

1. ConceptIn the design of the elevator, our requirements are: Serving passengers quickly Highest proficiency Safety Low costExpending on our list of attribute, we speculate that the elevator control would consist of 5 modules: Power supply Buttons includes in-car buttons, up-down call buttons at each floors. Sensors contain of the floor sensors (to tell microcontroller that car has reached exact position), and the coming sensors (to signal the microcontroller to reduce the speed of the motor). Actuator consists of two motor to lift car and drive the doors. Display module to indicate the position of the car on 7 segments LED and led to light up buttons when they are pressed.

2. Definition2.1 Operational specification1. On each floor there are up and down call buttons for the elevators. Depending on which way, the user presses one of the call buttons. Once in the elevator the user chooses his destination by pressing the appropriate button inside the card. The elevator moves to the desired floor and the user disembarks.2. Because this project have the human-to-product interface, it is necessary to have a clear display module to inform the passengers the position of the elevator so that they can use elevator more efficiently. The operational specification of display module list as following: The buttons are lighten up by green LEDs when they are pressed. The 7 segment LED indicate the position when the car reaches each floors. The arrows (also using LEDs) indicate the direction of the car.3. The floor sensors send signal to the controller that the car has reached the exact position to stop.The coming sensor send signal to the controller that the car should reduce speed and ready to stop.4. Two power circuits to control the main motor and the motor that drives the door.The speed of two motors will be control by pulse width modulation (PWM)

2.2 Basic Block Diagrams

The ATMegal6 was chosen for the prototype development. The Mega16 is pin-for-pin compatible with the smaller-memory model ATMega8535 as well as with the larger-memory model ATMega32. This allows some freedom during the design phase. The option of increasing the memory model may be needed, since we do not know exactly how much code space is required in either unit. At the end of the project, and after the features have ceased to creep, if the code would fit into a potentially less expensive component with a smaller memory size, that choice is available as well.3. Hardware Design

3.1 AVR MicroprocessorAVR is a member of microcontrollers manufactured by Atmel production. The reason we choose AVR is that: compared with the 8-bit microcontroller chip other, AVR has many superior properties over the whole of the application (user) and especially on the functionsBesides programming in ASM, the structure is designed compatible AVR C.Resources on the source code, documentation, application notes on the internet are great.Most AVR chips have features (features) follows: Can be used up to 16MHz clock, or use the internal clock of up to 8 MHz (error 3%) Flash program memory can be reprogrammed many times and large, have SRAM (static RAM) is larger, and especially the memory storage is EEPROM programming. Multiple input output (I / O PORT) two directions (bi-directional). 8 bits, 16 bits timer / counter integrated PWM. Analog Converters - Digital resolution 10 bits, channels. USART serial interface (compatible with standard serial RS-232). Serial Interface Two-Wire-Serial (I2C compatible) Serial Interface Serial Peripheral Interface (SPI)

In this project we choose ATmega 16

3.2 Power Supply

The supply power of the implemented circuit need to have a capability of maintaining be a steady voltage level despite vary current demands and input voltage variations. For this purpose, we use IC 7805

LM 7805 is used very simple with input pin will be the (9-24V), common leg for ground, which is connected mass, the output pin is 5V to feed the circuit.Also we will use the power supply of the PC to generate the 12V sources from the 220V AC

The role of capacitors is to store and release electricity to smooth out noise, surges, and sags. Without the capacitors, the 7805 would still output 5 V but wouldnt react as quickly to changes in supply and demand, and thus it wouldnt provide as clean of a regulated output.

3.3 ButtonBecause ATmega16 has a limited number of pins and this system requires quite many buttons to operate, we use each of three pins to take the input of each group of buttons. Here we use matrix 3x8 like the following figure

3.4 Floor sensorsUse the same matrix as buttons

3.5 Display moduleTo display the position of the car, we use 7 segment LED, to light up background of the pressed buttons, we use green LED. To control all of these LED, we use IC 74HC595

The 74HC/HCT595 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A. The 74HC/HCT595 is an 8-stage serial shift register with a storage register and 3-state outputs. The shift register and storage register have separate clocks.Data is shifted on the positive-going transitions of the SH_CP input. The data in each register is transferred to the storage register on a positive-going transition of the ST_CP input. If both clocks are connected together, the shift register will always be one clock pulse ahead of the storage register. The shift register has a serial input (DS) and a serial standard output (Q7) for cascading. It is also provided with asynchronous reset (active LOW) for all 8 shift register stages. The storage register has 8 parallel 3-state bus driver outputs. Data in the storage register appears at the output whenever the output enable input (OE) is LOW.

4. Software DesignBuild and Test Prototype Hardware

4.1. Display function using 74HC595void display (unsigned char x, unsigned char y, unsigned char z, unsigned char w){ Int i,j,k,l,t1,t2,t3,t4; for(i=0;i3)&0x07; call_down = (PINA>>6)|((PINB3)&0x07; coming_sensor = PINC&0x07; scan(); display(code[seg_led],down_led,up_led,button_led); if(button == 1){ dest_floor = 1; go_up(dest_floor); door(); } else if(button == 2){ dest_floor = 2; go_up(dest_floor); door(); } else if(button == 3){ dest_floor = 3; go_up(dest_floor); door(); } else if(button == 4){ dest_floor = 4; go_up(dest_floor); door(); } else if(button == 5){ dest_floor = 5; go_up(dest_floor); door(); } else if(button == 6){ dest_floor = 6; go_up(dest_floor); door(); } }}