The Hybrid Air Taxi

One pilot / Two passengers: 兩名乘客 / 一名飛行員

AT-3:The Coaxial Helicopter of the Next Generation

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TECHNICAL HIGHLIGHTS 技術第一亮點  

Safe and Reliable Electric Vertical Take Off & Landing!

Affordable and Sustainable solution.

New Electro-Hybrid drive, long range electric flight.

Fast employment for civil and defense air mobility and surveillance solutions.

SAFETY-FIRST HIGHLIGHTS 安全第一亮點  

  1. Proven Coaxial Technology:成熟的共軸技術
  2. Goal for Future Zero Emission:未來的零碳排放目標
  3. Renewable and Sustainable Energy:可再生和可持續的能源
  4. High-Speed up to 250Km/h:最高時速可達 250Km/h
  5. Autorotation Capability:自轉降落著陸能力
  6. Electric Drive with Range Extender:電動直升機+增程器
  7. Low Noise Level:低噪音水平
  8. Stable and Agile even in Strong Wind:強風中也能穩定敏捷飛行
  9. Less Mechanical parts than Multi-Copter:機械零件比多軸直升機少
  10. Lower Operating Costs:較低的營運成本
  11. Long Endurance (Generator/Range Extender):長續航力 (發電機/增程器)
  12. Two passengers One pilot:兩名乘客一名飛行員
Coaxial Helicopters for Everybody

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The Perfect Helicopter? 

Understanding Coaxial Rotor Design

Coaxial rotor designs have been used on military helicopters for the better part of the last 75 years.

The Perfect Helicopter: Understanding Coaxial Rotor Design

A coaxial rotor eliminates the need for a tail rotor and creates a safer, more stable machine.

In order to understand how a design with two coaxial rotors far outperforms other helicopters, we have to examine the physics at play.

The physics of helicopters

For single-rotor helicopters, lift-off is generated through the main rotor rotating. This rotation generates torque about the main helicopter, which causes the main fuselage to spin around in the opposite direction. Early engineers designed the tail rotor to counter this torque and keep helicopters stable. Tail rotors are generally much smaller rotors mounted on a perpendicular axis to the main rotor. By controlling the speed of the tail rotor, the pilot can stabilize the craft as well as control the direction of the helicopter.

Slowing the tail rotor would cause the helicopter body to rotate in the opposite direction of the main rotor due to excess torque in that direction. Speeding up the tail rotor would do the opposite. Along with direction, helicopter pilots can control the yaw of the craft by adjusting the angle of the tail rotor. By pitching the tail rotor slightly up or down, the pilot creates a moment arm through the helicopter, which in turn adjusts the yaw of the craft.

Why a coaxial design is so much better

Now that we understand the basic mechanics of single-rotor helicopters, we can begin to see why coaxial rotors might present some advantages. By placing two rotors on a single axis and rotating them in opposite directions, a net-zero torque around the main body of the helicopter is created, keeping it very stable. Through both mechanical means and electronic means, each rotor is perfectly timed and controlled to cancel out the net torque of the other rotor in real-time. This allows the coaxial craft to achieve rather significant hovering capabilities when compared to their single-rotor brethren.

When you think of helicopters, you think of vertical takeoff and the ability to hover. Remove those aspects, and the helicopter functions identically to a plane. As a side note, vertical takeoff isn't exclusive to rotorcraft. However, planes that harness the ability without rotors – mainly the harrier jet – accomplish the task with much less efficiency and stability.

A helicopter's ability to hover and be stable is synonymous with its quality of being a helicopter. In coaxial designs, the improved ability to hover and maintain stable flight ultimately makes for better helicopters. Better helicopters mean that they are easier to control and much safer for the occupants. Theoretically, if one rotor broke in a coaxial system, the craft could still be landed safely.

Lastly, the application of coaxial rotors means that there is no inherent need for the craft to have a gyroscope to provide stability. The rotational effects of both rotors provide for a near-perfect gyroscope, improving the stability of the craft once more.

So why don't we see more coaxial helicopters? They aren't without their faults.

Issues with coaxial helicopters

The first main fault is that the timing of the two rotor blades needs to be near perfect. Speed and directional changes need to be achieved together. Even the slightest fault in calibration essentially makes the aircraft unstable and impossible to fly. A fault in calibration is worse than you probably think for the craft's ability to fly. If the timing is off enough, coaxial helicopters won't produce enough lift to even leave the ground and end up just spinning on the tarmac.

RELATED: BOEING'S LATEST MILITARY HELICOPTER TAKES FLIGHT

On top of the need for accuracy in the tuning of the rotors, these rotors tend not to be as responsive as a single rotorcraft. When you make an aircraft more stable, you generally make precise movements harder to achieve – it's a constant tradeoff in aerospace engineering. While coaxial helicopters are safe and efficient, they are not well suited for applications where pilots need fine maneuverability. They are, however, perfect for applications where precise hovering is needed.

The coaxial rotor design is one of the most prominent helicopter designs to date. While it has its inefficiencies; it won't be going away anytime soon. The stability of the design is popular within the hobbyist community and even many military and rescue helicopters to date. If you were designing a helicopter, which design would you choose?



CDS:Coaxial Drive Systems

In 2003, the world's first "unmanned" coaxial helicopter with a payload of 100kg was successfully developed and lift off in Taichung, Taiwan, by YOSHINE HELICOPTERS using a patented "CDS" technology!

2003年,祐祥載重100公斤的『共軸無人直升機 』在台中『漢翔公司』協助在漢翔園區起飛!

  

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2003 CDS Shown at Duxford UK Helitech 2003
英國展出 創造了歷史 

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2005年,美國的PM科技雜誌報導了“EZYCOPTER”made by Yoshine Helicopters of Taiwan 為全球第一架「無尾旋翼」個人休閒運動「雙主旋翼」共軸直升機,但未來也有國防軍事用途發展潛力。

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CDS 解決了直升機「反扭力」問題,提供直升機『自動平衡』或『自動排檔』的能力!

2004年全球第一架 “CDS” 技術研製成功

傳統直升機《手排》飛控方式 vs. 共軸直升機《自排》飛空解決方案

牛頓定律:任何動力都有一個『力量相等/方向相反』的反作用力。 

【CDS】傳動系統讓直升機起飛時,扭力自動平衡,將平衡『自動化』,解決了「扭力平衡」問題!

用【CDS】研製直升機就像用『CPU』研製電腦一樣,創意可以無窮,商機可以無限。

世界已有多國採用【CDS】趨勢,研製救護及消防直升機,軍校用於教學。

新一代的波音、斯考斯基等的『軍用直升機』也是採用【CDS】概念。

2006年全球第一架應用CDS研製的『救護直升機』在『巴黎航空展』亮相!

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 "CDS":新一代無扭力直升機的飛控系統

  

  

"CDS":潛在市場

(1)個人直升機:適個人超輕休閒運動飛行的直升機。 

(2)無人直升機 載重三百公斤的無人直升機,供農漁牧及國防軍事用途。 

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新一代CDS技術趨勢

『CDS』同軸反轉直升機,已漸成歐美直升機核心驅動技術主流 ......

祐祥直升飛機股份有限公司 
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