多功能護理床的機構設計與仿真分析外文文獻翻譯、中英文翻譯
多功能護理床的機構設計與仿真分析外文文獻翻譯、中英文翻譯,多功能,護理,機構,設計,仿真,分析,外文,文獻,翻譯,中英文
Mechanism Design and Simulation Analysis of Multifunctional Nursing BedLizong Lin, Song Zhang, Xinglong Hu School of Mechanical and Power EngineeringEast China University of Science and Technology, Shanghai, ChinaE-mail: lizonglin@online.sh.cnE-mail: skyzhangsong@163.comAbstract-This research develops a new multifunctional nursing bed that can realize the movements of turning left and right sides and defecating on the bed for clinical use. And use the ADAMS to analysis the effects to the motor torque from the force on the rotated board, friction of contact pair and space position. By analysis of dynamic on the model of the main mechanism can get the curves and the influences of torque, which plays an important guiding role in selecting appropriate motor and installation structure.Keywords- nursing bed, ADAMS, virtual prototyping, dynamic analysisI. INTRODUCTIONNursing beds as parts of medical equipments are necessary for hospital care, and has been widely used in hospitals, nursing homes, retirement homes and many other fields. However, the prices of good quality nursing beds are expensive, the new study can reduce the cost and the difficulty of care, for example, to the patients resting on the bed for a long time, their turning over and lifting back required nurses have sufficient physical strength. Common beds just have head up, leg flexion and extension functions, this bed adds the function as rolling around, defecating on the bed and so on as needed [1].II. MECHANISM DESIGNThe nursing bed can be divided into four parts by the structure and function as: bed body, control cabinet, a framework for activities, removable bedpan. Block diagram as in Fig. 1In the control cubicle, the installment has the master control board, the motor-driven board, the transformer, the switching power supply and so on. The control cubicle connects with the nursing bed by the connection. Except the fixed mechanism, the bed body also includes the drive motor and the vane organization. The active frame installment has the wheels, which may be separated from the nursing bed. In the frame there are the water tank, stool which can rise and fall and the hot air blower. The transportable bed pan also installs wheels and can insert into the activity frame. In addition, the control system also includes the wire operators, the LCD and so on. In the system there are six DC motors which complete the actions of rising and falling of the head, the flexion of the leg, rolling around of the left and right, opening and closing of the vane and rising and falling of the stool and so on.A. Bed Function.The bed activity functions including the rising and falling of the head, the flexion of the leg and the bed body tum sides which satisfied patient's active request basically, favors the patients to improve their blood circulation and prevents the bedsore. This nursing bed has designed the flexion of the leg conforms to human body's movement characteristic. The bed body side turns may divide into three movements: the left side to tum, the right side to tum and the even side. Fig. 2, Fig. 3, Fig. 4 is the bed body's three movements.B. Nursing FunctionThe defecation function is rare in other electric nursing bed which suits the paralysis patient especially. In the middle of the bed body there is a rectangular opening, where can only seen two vanes in the normal condition. When defecating, the vane turns down to makes a breach, then the defecation device rise. After the defecation completed, the vane upturns continues to fill the gap. The defecation device is composed of the active frame and the motion bed pan which can inserts into the frame, and the entire frame can coordinate to load the bed body. The nursing bed can also provide the functions of spraying water and drying. In the active frame installed the water tank, the hot air blower and the solenoid valve. The water tank has a water pump, heater, the temperature sensor and the water level sensor. It can be realized that the water temperature establishment, the water temperature maintains and the water tank volume automatic increase and so on under the controller's control. The patient who is sick bed in long-term is the major recipients of this nursing bed. Before defecate, press the key “stool raise“ on the remote control, two vanes open, and then the stool raise, plate of the stool erects automatically, and so as to the bed pan. The patient can defecate after these movements completed. After the defecation completes, press corresponding key, carries on the flushing first, then uses hot blast drying, which has manifested the human nursing function. The water for flushing is preserved in the tank, and use heating wire to maintain the temperature. It's needed to gather and process of the temperature in order to realize the control of it, the gather can completed by the sensor, the process and control can completed by the monolithic integrated circuit. As a result of the patient's defecate time is uncertainty, and requests maintains the temperature constant, for the aim of providing appropriate temperature momentarily.III. SYSTEM MODELINGA. ModellingNursing bed is a very complex structure, which can divided into the mechanical component of the bed body, the active frame, the transportable bed pan, the electronic control system and the motor driven system by the structure and the function. Fig. 5 is the geometric modeling graph of the vane [2].I Right rotated board 2 lever of right rotated board 3 Driving arm of right rotated board 4 Motor of right rotated board 5 Motor of left rotated board 6 Driving arm of left rotated board 7 lever of left rotated board 8 Left rotated board 9 Door axis of rotated boardFigure 6 Lever and driving arm of rotated board I Lever of rotated board 2 Driving arm of boardB. Contact Pairs ProcessingFig. 6 is the geometric modeling graph of the vane lever and actuating arm. The axis of one of the vane lever ends fixed with the vane, the other end has a curve groove. Both sides of the vane actuating arm are round axes, whose axle centers are parallel. One axis is linked with the motor and fixed, the other coordinated with the curve groove to form a contact. The motor caused the actuating arm to reverse, which can realize opening and closing of the vane.III. SIMULATION ANALYSIS The purpose of dynamics simulation of the vane is to analysis the influence to the torque in the different condition, and guide to improve the design and select the appropriate drive motor [3]. A. !influence to Torque from ActionThe sizes of the left and right vanes are not equal, but the motors are same. Select the right one which has a greater area and force to analysis [4]. Select the action point in middle of the two vanes, and the arm of the force is 15 cm. The friction coefficient of the steel is 1.2 to 1.4, and 0.02 to 0.05 after lubricated, takes the friction coefficient of 0.05.The curves are not smooth seen from Fig.7 and Fig.8, as the high frequency component coupling to them analyzed mathematically, which were considered to be vibration in actual. It is also discovered that the vane has a phenomenon of vibration, which meet with the simulated data when testing. The vibration has a relation to the stress, nature of material, rigidity of material, osculating curve of rigid body, friction coefficient and so on. It is inferred from the simulation analysis that the bigger stress the smaller vibration. Make sure the contact surfaces are smooth when design the curve groove of the vane lever to reduces the nonessential vibration. Fig.9 is the angular velocity when the stress is SOON, the vibration situation can be observed obviously [5].The actual action to the vane from the patient is not constant but increases gradually when the vane turns to the level position nearby. So that, select the larger motor torque as far as possible to prevent overloading.B. lrifluence to Torque from Friction CoefficienttThere are three kinds of restraints altogether in the vane simulation: fixed restraint, hinge restraint and contact restraint. The fixed restraint cannot cause the friction force, but the hinge restraint and the contact restraint can. The hinge to the hinge restraint can be processed as sliding bearing. The friction coefficient of sliding bearing is small. The dynamic friction coefficient of sliding bearings is 3.0xl0-3 and the static friction coefficient is 4 .0 x 10 - 3 ? Although the contact restraint is also a kind of sliding friction, but it cannot simply processed as sliding bearing, because the contact is complex, and the stress is also big. Fig. 10 represents the contact force when lever axis and curve groove of actuating arm have a stress of SOON, where the biggest can reach 1800N.Fig. 11 and Fig. 12 respectively represent the torque chart in the friction coefficient of 0.07 and 0.31, and the stress of SOON.Compared with Fig. 11 and Fig. 12, it cannot obviously see the changes of the torque, so as the curve. The biggest diversity is that the vibration reduces when friction coefficient is 0.31. The friction coefficient f.I. has not caused the biggest moment of force change obviously, only has a tendency of enlargement, after the process of filter smooth correlative value [6].C. lrifluence toTtorque from Space PositionWhen design the vane, not only consider the actual installment space and the request size, but also need to pay attention to the relations in the space position between the revolution axis of the vane lever and the revolution axis of the actuating arm. Because their positions are not only relating whether the vane can operation normally, but also affects the biggest driving force. Use the coordinates system as Fig. 13 when establish the coordinate. Fig. 14, Fig. 15 and Fig. 16 are the changing graph of biggest torque in VI-452 Volume I 2010 2nd International Conference on Mechanical and Electronics Engineering (ICMEE 2010) different space position [7]. And the stress is SOON, friction coefficient is 0.03.Comparing the data in the different condition may see that the time and the biggest torque have changed remarkably. And the movement time is the smallest in condition 3, so as the force moment. In the condition 2, the lever arm separated from the drive shaft in the moving procession. When actually determine the data, should consider about the motor of torque, size and structure and so on, the best effort may not be the most suitable [8]. Through the analysis of dynamics simulation to the vane that:1) The motor driven torque is small. In the process of simulation analysis, exerted 500N force to the vane and calculates the biggest torque of the motor is 25Nm, but actually the torque is 18Nm, therefore present the phenomenon of the vane asthenia when raising. Here takes 500N force, it is only the average action size in the normal condition. When actual use, possibly bigger than 500 N, so that it must be considered that the motor should have a sufficient remainder actuation torque to satisfY the request under the dissimilar condition. 2) The influence of the friction coefficient is not big to the torque. Under the condition of constant action, it's indicated that the friction coefficient has a very small influence to the torque, through takes different friction coefficient to calculate the biggest torque. 3) The space position of the rotation axis has a bigger influence to the torque, the condition 1 and 3 have a difference of 1 ONm, and the movement time also changing.V. CONCLUSIONDiscussed the influence factors include the driving torque action, friction coefficient, space position and so on by the dynamics and the kinematics analysis to the vane of the nursing bed, which improved the theory basis to the design of the structure, and provided the science basis to the performance evaluation analysis of the bed. This bed may also increase the network communication function to the system, which will cause it to be able to transmit the information automatically to the superior machine, and realizing the long-distance patient care monitor.Reference[I] Fang Jinbo, Chen Hong. “The Challenges to Nurses Work from Aging Populations,“ Journal of International Nursing. vol. 3, Feb. 2004,pp.147-149.[2] Zheng Jiaorong. ADAMS-Getting Started with Virtual Prototyping Technology and Improve. Beijing: Mechanical Industry Publishing House. 2002. I [3] Peng Qibo, Li Haiyang. “Modeling and Simulation of Robot Maoipulator Based on Virtual Prototyping Technology,“ Journal of East China University of Science aod Technology, vol. 33, Jun. 2007, pp.58-62. [4] Jin Xin, what Yulin aod Liu Hua. “The Wind-driven Generator Coupled Oscillation Analyzes,“ Journal of Vibration aod Shock, vol. 26,Jun.2007,pp.144-147.[5] Liu Jun, Lin Lizong, Liu Xiaoping aod Waog Gaog. “ADAMS Flexible Body Movement Simulation Analytical Study and Utilization,“ Modem Maoufacture Project, vol. 5, May. 2004, pp. 53-55. [6] Dong Ligaog, Chen Weihai aod Zhang Jianbin. “Kinematic Analysis aod Simulation for Hybrid Type Cable-driven Maoipulator, “ Journal of System Simulation, vol. 19, Sep. 2007, pp. 4007-4011.[7] Waog Yeo “Development of Control System for Multifunction Nursing-bed,“ Control & Automation, vol. 22, Jul. 2006, pp. 117- 119. [8] Jiaog Hao, Waog Wei, Liu Yongping. “The Study on the Multifunctional Nursing Bed,“ Manufacturing Automation, vol. 31, Jun. 2009,pp. 71-73.摘 要本研究開發(fā)了一種新型的多功能護理床,可實現(xiàn)床上左右轉(zhuǎn)彎、排便等功能,供臨床使用。并利用 ADAMS 分析了旋轉(zhuǎn)板受力、接觸副摩擦力和空間位置對電機轉(zhuǎn)矩的影響。通過對主機構模型的動力學分析,可以得到主機構的曲線和扭矩的影響,這對選擇合適的電機和安裝結構具有重要的指導作用。關鍵詞:護理床、Adams、虛擬樣機、動態(tài)分析多功能護理床的機構設計與仿真分析李宗林、宋章、胡興隆機械與動力工程學院華東理工大學,上海1 引言病床作為醫(yī)療設備的一部分,是醫(yī)院護理的必備品,已廣泛應用于醫(yī)院、療養(yǎng)院、養(yǎng)老院等諸多領域。然而,優(yōu)質(zhì)護理床的價格昂貴,新的研究可以降低成本和護理難度,例如,對于長期臥床的病人,他們的翻身和后撤需要護士有足夠的體力。普通床只有頭向上、腿彎曲和伸展功能,這種床根據(jù)需要增加了翻滾、在床上排便等功能[1]。2 機構設計護理床按結構和功能可分為四部分:床體、控制柜、活動框架、活動便盆。方框圖如圖 1 所示??刂乒駜?nèi)設有主控板、電機驅(qū)動板、變壓器、開關電源等。控制柜通過接線與護理床相連。床體除固定機構外,還包括驅(qū)動電機和葉片機構?;顒涌蚣苎b置具有輪子,可與護理床分離。框架內(nèi)有水箱、可升降的凳子和熱風機。移動式便盆還安裝了輪子,可以插入活動框架中。此外,控制系統(tǒng)還包括電線操作器、液晶顯示器等。系統(tǒng)中有六臺直流電機,分別完成了頭部的升降、腿部的彎曲、左右轉(zhuǎn)動、葉片的開閉和凳子的升降等動作。A.床功能。床上活動功能包括頭的升降、腿的彎曲和床體的兩側,基本滿足患者的活動要求,有利于患者改善血液循環(huán),防止褥瘡的發(fā)生。本護理床設計了符合人體運動特點的腿部屈曲。床體側彎可分為三種運動:左側至臀部、右側至臀部和平坦一側。圖 2、圖 3、圖 4 是床體的三個運動。B.護理功能排便功能在其他特別適合癱瘓病人的電動護理床上很少見。床體中間有一個矩形開口,正常情況下只能看到兩個葉片。排便時,風向標向下開,排便裝置上升。排便完畢后,風向標繼續(xù)向上翻,填補空隙。排便器由活動架和活動床盤組成,活動床盤可插入機架內(nèi),整個機架可配合加載床體。護理床還具有噴水、烘干功能。在主動框架中安裝了水箱、熱風機和電磁閥。水箱有水泵、加熱器、溫度傳感器和水位傳感器。在控制器的控制下,可以實現(xiàn)水溫的設定、水溫的保持和水箱容積的自動增大等功能。長期臥床的病人是這張護理床的主要接受者。大便前,按遙控器上的“大便升高”鍵,兩個葉片打開,然后大便升高,大便板自動豎起,以便盆為準。這些動作完成后,病人可以大便。排便完畢后,按相應鍵,先進行沖洗,然后采用熱風干燥,體現(xiàn)了人的護理功能。沖洗用水保存在罐內(nèi),用加熱絲保持溫度。為了實現(xiàn)對溫度的控制,需要對溫度進行采集和處理,采集由傳感器完成,過程和控制由單片機完成。由于病人的排便時間不確定,要求保持體溫不變,目的是暫時提供適當?shù)捏w溫。3 系統(tǒng)建模A.造型護理床是一個非常復雜的結構,它由床體的機械部件、活動框架、移動式床盤、電子控制系統(tǒng)和電機驅(qū)動系統(tǒng)的結構和功能組成。圖 5 是葉片的幾何建模圖[2]。i 右旋轉(zhuǎn)板 2 右旋轉(zhuǎn)板杠桿 3 右旋轉(zhuǎn)板驅(qū)動臂 4 右旋轉(zhuǎn)板電機 5 左旋轉(zhuǎn)板電機 6 左旋轉(zhuǎn)板驅(qū)動臂 7 左旋轉(zhuǎn)板杠桿 8 左旋轉(zhuǎn)板 9 旋轉(zhuǎn)板門軸圖 6 轉(zhuǎn)盤杠桿及驅(qū)動臂 I 轉(zhuǎn)盤杠桿 2 轉(zhuǎn)盤驅(qū)動臂b.接觸副處理圖 6 是葉片杠桿和執(zhí)行臂的幾何建模圖。其中一個葉片桿的軸端與葉片固定,另一端具有曲線槽。葉片執(zhí)行臂兩側為圓軸,軸中心平行。一軸與電機連接固定,另一軸與曲線槽配合形成接觸。電機使執(zhí)行臂反轉(zhuǎn),實現(xiàn)葉片的啟閉。4 仿真分析葉片動力學仿真的目的是分析不同工況下對轉(zhuǎn)矩的影響,指導改進設計,選擇合適的驅(qū)動電機[3]。左右葉片的尺寸不相等,但電機相同。選擇面積和分析力較大的右側區(qū)域[4]。選擇兩個葉片中間的作用點,力臂為 15cm。鋼的摩擦系數(shù)為 1.2~1.4,潤滑后為 0.02~0.05,摩擦系數(shù)取 0.05。從圖 7 和圖 8 可以看出,這些曲線并不平滑,因為對它們的高頻分量耦合進行了數(shù)學分析,這在實際中被認為是振動。同時發(fā)現(xiàn)葉片存在振動現(xiàn)象,試驗時與模擬數(shù)據(jù)吻合。振動與應力、材料性質(zhì)、材料剛度、剛體接觸曲線、摩擦系數(shù)等有關。仿真分析表明,應力越大,振動越小。在設計葉片桿的曲線槽時,應保證接觸面光滑,以減少非必要的振動。圖 9 是應力很快時的角速度,可以明顯觀察到振動情況[5]?;颊邔θ~片的實際作用不是恒定的,而是當葉片轉(zhuǎn)到附近的水平位置時逐漸增加。這樣,盡量選擇較大的電機扭矩,防止過載。b.摩擦系數(shù)對扭矩的影響 t葉片模擬共有三種約束:固定約束、鉸鏈約束和接觸約束。固定約束不能產(chǎn)生摩擦力,但鉸鏈約束和接觸約束可以。鉸鏈到鉸鏈約束裝置的鉸鏈可以作為滑動軸承處理?;瑒虞S承摩擦系數(shù)小?;瑒虞S承的動摩擦系數(shù)為 3.0xl0-3,靜摩擦系數(shù)為 4.0x 10-3?雖然接觸約束也是一種滑動摩擦,但由于接觸復雜,應力也很大,不能簡單地作為滑動軸承處理。圖 10 為執(zhí)行臂桿軸和曲線槽受力快時的接觸力,最大可達 1800N。圖 11 和圖 12 分別表示摩擦系數(shù) 0.07 和 0.31 中的扭矩圖,以及 Soon 的應力。與圖 11 和圖 12 相比,它看不到扭矩的變化,也看不到曲線。最大的差異是摩擦系數(shù)為 0.31 時振動減小。摩擦系數(shù) f.i.并沒有明顯引起最大力矩的變化,只是在濾波后有增大的趨勢,平滑相關值[6]。c.從空間位置到扭矩的偏差設計葉片時,不僅要考慮實際安裝空間和要求尺寸,還要注意葉片杠桿旋轉(zhuǎn)軸與執(zhí)行臂旋轉(zhuǎn)軸之間的空間位置關系。因為它們的位置不僅關系到葉片能否正常工作,而且影響到最大的驅(qū)動力。建立坐標時,使用如圖 13 所示的坐標系。圖 14、圖 15 和圖 16 是 2010 年第二屆國際機電工程會議(ICMEE 2010)第一卷 VI-452 中不同空間位置的最大扭矩變化圖[7]。應力很快,摩擦系數(shù)為0.03。通過比較不同工況下的數(shù)據(jù),可以看出時間和最大轉(zhuǎn)矩都發(fā)生了顯著變化。在條件 3 中,運動時間最小,也就是力矩。在條件 2 下,在移動過程中,杠桿臂與驅(qū)動軸分離。在實際確定數(shù)據(jù)時,應考慮電機的轉(zhuǎn)矩、尺寸和結構等,盡最大努力可能不是最合適的[8]。通過對葉片的動力學模擬分析,得出:(1)電機驅(qū)動力矩小。在仿真分析過程中,對葉片施加 500N 的力,計算出電機的最大轉(zhuǎn)矩為 25Nm,但實際轉(zhuǎn)矩為 18Nm,因此在升高時會出現(xiàn)葉片無力現(xiàn)象。這里承受 500N 的力,它只是正常情況下的平均作用尺寸。實際使用時,可能大于 500N,因此必須考慮電機應具有足夠的剩余驅(qū)動扭矩,以滿足不同條件下的要求。(2)摩擦系數(shù)對扭矩的影響不大。結果表明,在恒定作用下,摩擦系數(shù)對扭矩的影響很小,通過采用不同的摩擦系數(shù)來計算最大扭矩。(3)旋轉(zhuǎn)軸的空間位置對扭矩影響較大,工況 1 和工況 3 相差 1 on m,運動時間也發(fā)生變化。5 結論通過對護理床葉片的動力學和運動學分析,探討了驅(qū)動力矩作用、摩擦系數(shù)、空間位置等因素對護理床結構設計的影響,為護理床性能評價分析提供了科學依據(jù)。該床還可以增加系統(tǒng)的網(wǎng)絡通信功能,使其能夠自動將信息傳輸?shù)缴衔粰C,實現(xiàn)遠程病人監(jiān)護監(jiān)控。參考文獻[1]方錦波,陳紅?!弊o士面臨的挑戰(zhàn)來自老齡化人口,《國際護理雜志》。第3 卷,2004 年 2 月,第 147-149 頁。[2]鄭嬌榮.Adams 開始使用虛擬原型技術并進行改進。北京:機械工業(yè)出版社。2002。[3]彭其波,李海陽.基于虛擬樣機技術的機器人毛管建模與仿真”,《華東理工大學學報》2007 年 6 月第 33 卷第 58-62 頁。[4]金鑫,什么榆林奧德劉華?!憋L力發(fā)電機耦合振動分析”,《振動與沖擊雜志》,第 26 卷,2007 年 6 月,第 144-147 頁。[5]劉軍,林立松,劉小萍.亞當斯柔性車身運動仿真分析研究與應用,“現(xiàn)代汽車制造項目,第 5 卷,5 月。2004 年,第 53-55 頁。[6]董立剛,陳威海,奧德,張建斌.混合式電纜驅(qū)動的貓形裝置的運動分析AOD 模擬,“系統(tǒng)模擬期刊,第 19 卷,2007 年 9 月,第 4007-4011 頁。[7]Waog Yeo,“多功能護理床控制系統(tǒng)的開發(fā)”,《控制與自動化》,第 22卷,2006 年 7 月,第 117-119 頁。[8]焦浩,沃偉,劉永平.多功能護理床的研究,“制造自動化,2009 年 6 月 31日,第 71-73 頁。
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