外文资料翻译-驱动汽车转弯时的效应

外 文 资 料 原 文 : 河南科技大学毕业设计 (论文 ) 1 E F F E C T O R co u s co u p l in g s a ls o p r o v id e a s el f - lo ck i n g t o r q u e w h e n co r n er in g , d u e sp ee d d i ff e r e n c b e tw e t h e d r iv in g w h ee D u r in g st e ad y st at e co r n e r i n g , a s s h o w n i n f ig u r e 1 0 , t h e s lo w in s id e w h e e l te n d s b e a d d it io n a ll y d r i v t h r o u g h t h e v is co u s c o u p g b y t h e o u t s id e w h ee l. F ig u r e 1 0 : Tr ac t iv e f o r ce s f o r a f r o n t - w h ee l d r i v e v e h ic d u r in g st e ad y st at e co r n er in g Th e d i f f er e n c e b et we e n th e Tr a ct i fo r c D r y a n d D S L r e s u lt s i n a y mo t M , w h i h b e co mp e n sa t b y a h ig h e r e r a l f o r c e, an d h e n c e a g e r s l a n g a f t th e f r o n t a x T hu s t h e in f lu e n c e o f a v i sc o u s c o u p g a f r o n t - w h e d r i v e v eh i c o n s el f - s t in g t en d s to w ar d s a n u nd s t ee r in g c h ar ac te r is t Th b e ha v io r is t o t a c o n s i st e n t h t h e h an d li n g b i as o f m o d e r n v e h ic le s w h ic h al l u n d e r st e d u r in g st e ad y s t at e co r n er in g ma n e u v e r s . Ap p r o p r ia t es t r es u lt s ar e s h o w n in f ig u r e 1 1 . F ig u r e 1 1 : co mp a r i so n b e t we v e h ic le s f it t w it h a n o p e n d i ff e r e n t ia l a n d v is co u s co u p l in g d u r i n g s t ea d y s t at e co r n er in g . Th e as y m r i c d i st r i b u t io n o f t h e t r ac t iv e f o r ce s d u r in g c o r n e r in g s h o w n f ig u r e 1 0 i mp r o ve s a ls o t h e s t r a ig h t - li n e r u n n i n g . E v er y d e v ia t io n f r o m t h e s t r a ig e p o s it io n ca u s t h e w h ee r o o n s h t d if f e r e n t r ad Th e d i f f er en c e b et w ee n t d r iv i n g f o r ce s an d t h e r e su lt in g ya w mo me t r ie s t o r e st o r e t v e h ic s t r a ig h t - l in e r u n n i n g ag a ( s ee f i g u r e 1 0 ) . Al t h o u g h t h es e d ir e ct io n d e v i at io n s r es u o n s ma d i ff e r e n ce s w h ee l t r a v r a d i i, t h e r o t a n a l d if f e r e n ce s es p ec ia l h ig h sp ee d s a r e g e en o u g h f o r a v is c o u s co u p li n g f r o n t d if f er e n t ia l b r i n g i mp r o v e me n s t r a ig h t - l in e r u n n in g . H ig h p o we r e d f r o n t - w h ee l d r iv e v e h ic le s f it te d w it h o p e n d i ff e r e n t ia o f te n s p t h e i n s id e w h ee w h e n e at in g o u t o f t ig h t c o r n e r s lo w g ea r. I n v eh i cl f i tt w l im it s li p v is co u s 河南科技大学毕业设计 (论文 ) d i ff e r e n t ia t h i s s p i n n i n g li e d a n d th e t o r q u e g e n er a t b y t h e s p ee d d if f e r e n ce b e tw e t h e w h e el s p r o v id e s a d d it io n a l t r a ct iv e ef f o r t f o r t h e o u t s id e d r iv i n g w h e e l. T h s h o w n f ig u r e 1 2 F ig u r e 1 2 : t r ac t iv e f o r c fo r a f r o n t - w h e d r iv e v eh ic w it h v is c o u s it s d i f f er en t ia l d u r i n g a cc e a t io n a b e n d Th e a cc r a t io n ac it y t h u s r o v e d , p ar t ic u l ar w h e n tu r n in g o r a cc el er a t in g o u t o f a T- ju n c t io n m an e u v e r ( i. e. ac ce le r at i f r o m a st o p p p o s it io n a “T ” in t er s ec t io n - r ig h t o r le f t t u r n ) . F ig u r 1 3 an d 1 4 s h o w s th e r es u l o f a cc e at io n t es t s d u r i n g st e ad y s t at e c o r n e r i n g w it h a n o p d i ff e r e n t ia l a n d w it h v is co u s li e d - s l d if f e r e n t F ig u r e 1 3 : a cc el er a t io n c h ar ac te r i st ic s f o r a f r o n t- w he e l d r iv e v e h ic w it h o p d if f e r e n t ia l o n w e t as p ha a r a d iu s o f 4 0 m ( f i x st e er in g wh e e l a n g l e t h r o u g h o u t t es t ) . F ig u r e 1 4 : A cc e at io n Ch ar ac te r i st ic s f o r a F r o n t - W h ee l Dr iv e h i cl e w it h Vi s co u s Co u p l in g o n A s p h a a Ra d iu s o f 4 0 m ( F ix e d s t ee r i n g w h e a n g t h r o u g h o u t te Th e v eh i cl e w it h a n o p d if f er en t i a ch ie v a v er ag e ac ce le r at io n o f 2 . 0 m / s w h i t h e h ic w t h e v i sc o u s co u p l in g r e ac h a v er a g e o f 2 . 3 m / s ( li e d b y en g in e - p o w e r ) . I n t h e t e st s , th e ma x i mu m sp d i ff e r e n c au s e d b y s p in n in g o f th e in s id e d r iv e n w h ee l w a s r ed u ce d f r o m 2 4 0 r p m w it h o p e n d if f e r e n t ia l 10 0 r p m w it h t h e v is co u s co u p l in g . D u r in g ac ce le r at io n i n a b e n d , f r o n t - w h e d r i v e ve h i cl i n g e n er a l t en d t o u n d s t ee r mo r e t h w h e n r u n n in g a st e ad y s p e T r e as o n f o r t h i s th e r e d u ct io n o f th e p o t en t ia l t o tr an s m e r a l f o r c t h e f r o n t - t ir e s d u e t o w ei g h t t r an s f e r t o t h e r e w h ee an d in c r e as lo n g it u d in a l f o r c a t t h e d r iv i n g w he e I n a n o p lo o p co n tr o l- c ir c l e- t es t t h i s c b e s ee n t h e d r o p o f t h e ya w in g s p e ( ya w r at e) a f t st ar t i n g t o ac ce le r at e ( T 0 i n F ig u r e 1 3 an d 1 4 ) . I t ca n a b e t a k f r o m F i g u r e 1 3 a n d F ig u r e 1 4 t h t h e y a w r at e o f t h e v e h ic w it h t h e o p d if f er en t ia l f a o f f mo r e r ap i d t h a n f o r t h e 2 2 河南科技大学毕业设计 (论文 ) v e h ic w it h t h e v is co u s co u p l in g st ar t in g t o a cc el er a t e. Ap p r o x t el y 2 s ec o n d s a f t st a r t in g t o a cc el er a t e, h o w ev e r, th e y a w r at e f al l- o f f g r a d ie n t o f t h e v is c o u s- co u p v e h ic l e in c r e as e s mo r e t h t h e v e h ic w it h o p d if f e r e n t Th e v e h ic w it h t h e li e d s l fr o n t d if f e r e n t ia l t h u s h a s a mo r e st a b in it i r ea ct io n u n d a cc el er a t in g d u r in g c o r n e r i n g th a n th e v e h ic w it h th e o p d if f er en t i r e d u c in g s u n d s t ee r. T h i s is d u e th e h ig h e r s li p t h e in s id e d r iv in g w h ee l c au s in g a n i n cr ea i n d r i v in g f o r t h r o u g h t h e v i s co u s co u p l in g t h e o u t s id e w h e e l, w h ic h i st r at e d F i g u r e 1 2 . Th e im b al a n t h e f r o n t w h ee l a tt r a ct iv e f o r c r e su lt s i n a y mo me n t M a ct in g d ir e ct io n o f t h e t u r n , co u n t er in g t h e u n d s t ee r. Wh e n t h e ad h es io n it s o f th e d r iv i n g wh e e a r e ex c ee d , t h e v e h ic w it h t h e v i sc o u s co u p g u n d e r st e er s mo r e n o t a b t h a n t h e v e h ic w it h t h e o p e n d if f er e n t ia l ( h e r e , 2 s n d s a ft e r st a r ti n g ac ce le r at e ) . O n v er y l o w f r i ct io n s u r fa c s u c h s n o w o r ic e, s tr o n g e r u n d e r s t ee r t o b e e x p e ct w h e n a cc e a t in g a cu r v e w it h a li e d s li p d i f f er en t ia l b ec au th e d r iv i n g w h e el s- co n n ec t t h r o u g h t h e v is co u s co u p g - ca n b e ma d e t o sp mo r e ea s il y ( p o we r - u n d e r - s t in g ) . T h i s ch ar a ct er is t ca n , h o w e v b e ea s il y co n tr o d b y th e d r iv e r o r b y a n au t o m at th r o tt mo d u la t in g t r a ct io n co n tr o l s y st e m. U n d e r t h e co n d it io n s a mu c h e as i t o co n t r o l t h a n a r e w h ee l d r i v e ca r. Wh i c a n ex h ib p o w o v st ee r i n g w h e n ac ce le r at i n g d u r in g co r n er in g ? Al l t h in g s , co n s id e r e d , t h e a d v a n t ag e t hr o u g h t h e s ta b i ac ce le r a t io n b e h a v io r o f a v i s co u s co u p li n g eq u ip p e d v e h i cl e d u r in g a cc e at io n th e s ma d is a d v a n t ag e o n s li p p er y s u r fa ce s . Th r o tt o f f r ea ct i o n s d u r i n g co r ne r i n g , ca u s b y r e le as i n g th e ac ce le r at o r s u d d e n u s u a l r es u i n a f r o n t - w h e d r iv e v e h ic tu r n in g in t o t h e t ur n ( t h r o t t o f f o v e r s t ee r in g ) . H ig h - p o we r e d mo d el es s s w h i ca n r e ac h h ig h er al a c ce at io n s s h o w t h e h e av ie r e io n s . Th t h r o tt o r t io n h a s s ev er ca u s s u c h k i n em at ic s in f l u e n o r t h e v e h i cl e at t t in g t r a v e l o n a s ma l 河南科技大学毕业设计 (论文 ) co r n er in g r ad iu s w it h r e d u c in g sp ee d . T h e e s se n t ia l r e a so n , h o we v t h e d yn am w ei g h t t r an s f e r f r o m t h e r ea r t h e f r o n t ax l e, wh ic h r e su lt s r e d u ce d s a n g le s o n t h e f r o n t a n d in c r ea s s li p - a n g le s o n t h e r ea r wh e e au s e th e r ea r wh e e ar e n o t tr an s m i n g d r i v in g to r q u e , t i n f lu en c e o n t h e r e ax t h is c as e is g r ea te r t h a n t h a t o f t h e f r o n t ax l e. T h e d r iv in g f o r c o n th e f r o n t w h ee b ef o r e t h r o t t o f f ( s F i g u r e 1 0 ) b ec o o v r u n n in g o r b r a k in g f o r ce s a ft e r w ar d s , w h ic h i s il lu s t r a te d f o r t h e v is co u s eq u ip p v eh i c F i g u r e 1 5 . F ig u r e 1 5 : Ba r k in g F o r c f o r a F r o n t - W h ee l D r i v e h ic w it h c o u s L im it S D if f e r e nt I m me d ia te af t a T h r o t t o f f M an e u v e r W h il e Co r n er in g th e in n e r w h ee l co nt in u t o t u r n m o r e s lo w t h a n t h e o u t e r w h ee l, t h e v is co u s co u p l in g p r o v id e s th e o u t wh e e l w it h th e la r g e r b r a k in g f o r c e B f . T h e f o r c e d i f f er e n c e b e t we t h e f r o n t - w h e el s a p p d ar o u n d th e c e nt e r o f g r av it y o f t h e v eh ic le c au s e s a y a w mo me n t M C 0G t h co u n te r a ct s th e n o r ma l t u r n - r ea ct io n . Wh e n co r n er in g b e h a v io r d u r in g a t h r o t t o f f ma n eu v co mp a r f o r v e h ic le s w it h o p e n d i ff er e n t ia ls a n d v is c o u s co u p l in g s, s h o w n F ig u r e 1 6 a n d 1 7 , th e s p ee d d i ff e r e n b et w ee n t h e t d r i v in g w h ee r e d u c w it h a v is c o u s d if f er en t ia l. F ig u r e 1 6 : T h r o t t o f f Ch a r a ct er i f o r a Fr o n h e Dr iv e h ic l e w it h a n o p D if f e r e nt i o n A s p h a a iu s o f 4 0 m ( O p e n Lo o p ) F ig u r e 1 7 : T h r o t t o f f Ch a r a ct er i f o r a Fr o n h e Dr iv e h ic l e w it h Vi s co u s Co u p l in g o n A s p h a a Ra d iu s o f 4 0 m ( O p e n Lo o p ) Th e y aw i n g s p e e d ( ya w r at e ) , a n d t h e r e iv e y a w in g an g ( i n ad d it io n t o t h e y a w an g w h ic h th e v e h ic wo u h a v e ma in t a in e d i n ca s e o f c o n t in u e d s t ea d y st at e co r n er in g ) s h o w a p r o n o u nc i n cr e as e a ft t hr o tt o ( e =0 s ec o n d s F i g u r e 1 4 a n d 1 5 ) w it h t h e o p e n d i ff e r e n t ia l. Bo t h t h e s u d d i n cr e o f th e ya w r at e a ft t h r o t t o f f an d a ls o t h e i n cr ea o f t h e r e la t iv e y a w an g a r e s i g n i f ic an t l y r ed u ce d t h e v e h ic e q u ip p w it h a v is c o u s li s li p d if f er en t ia l. 河南科技大学毕业设计 (论文 ) A n o r d r i v a s a f r o n t- wh e e l d r iv e v e h ic u s u a ll y o n l y ac cu st o t o n eu t r a l a n d u n d e r s te er in g v e h ic h a n d in g b e h a v io r , t h e d r i v t h e n b e s u r p r is b y su d d e n an d f o r ce f u l o v s t ee r in g r e io n a f t ab r u p t r e s e o f t h e t h r o t f o r ex a mp l e a b e w it h d e cr i n g r ad iu s . Th is v e h ic r e ac t io n fu r t h w o r s e n t h e d r i v o v c o r r e ct s fo r th e s it u at io n . Ac c id e n w h er e ca r s v e t h e r o a d t o t h e in n s id e o f th e cu r v e p r o o f o f t h o r r en c e. He n c e th e v is c o u s co u p li n g i mp r o v th e t h r o t t o b e h a v io r w h i r em ai n in g co nt r o b l e, p r e d ic t ab l e, an d sa f e r f o r a n a ve r a g e d r i v 2. E F F E C T R A G Th e v i sc o u s c o u p g a f r o n t- w h ee l d r iv e v e h ic w it h o u t A ( a n lo b r a k i n g s y s te m) h a s o n a v er y s ma i n f l u en c e o n t h e b r a k in g b e h a v io r o n s p l s u r f ac He n t h e fr o n t - w h ee l s a r e co n n ec te d p ar t ia l v t h e f r o w h e o n t h e lo w - s id e s l ig h t h ig h t h a n i n v eh i c w o p d if f e r e nt i O n t h e o t h e r s id e , th e b r a k e p r e s su r e t o lo t h e f r o n t- wh e e l o n th e h ig h - s id e s li g h t lo we r. T h e d if f e r e n ce s c b e m ea su r in s t r u t e d te v eh ic b u t a r e h ar d l y n o t ic ea b l e a s u b j ec ti v e as s e ss m en t . Th e lo c k i n g s eq u en c e o f f r o a n d r e a x i s n o t in f l u e n ce d b y t h e v is co u s co u p l in g . Mo o f f er e d to d a y h in d i v id u co n tr o l o f e ac h f r o n t w h e E tr o n A fr o n t - w h ee l d r iv e v e h ic le s mu s t al lo w f o r t h e co n s id e r a b d if f e r e nc e f f ec t iv e w h e in e r t b e tw e b r a k in g w it h t h e c lu t c h e n g ag an d d i se n g a g P ar t ia l co u p li n g o f t h e f r o n t w h ee t h r o u g h t h e v i s co u s u n d o e s n o t t h e r e fo r e co mp r o e t h e a ct io n o f th e A - a f ac t t h h a s b ee n co n f ir b y n u m er o u s t es t s an d b y se v e r a l i n d e p e n d en t ca r ma n u f a ct u r e r s . Th e o n e t h e o r e ti ca l e x ce p t io n t h i s o cc u r s o n a s p l s u r f a i f a ya w m o me n t b u il d - u p d e la y o r M o t u ct io n ( Y M R) in d th e co n t r o l u n F ig u r e 1 8 s h o w s t yp ic b r a k e p r e ss u r e s e q u e n ce s , w it h a n d w it ho u t . f ig u r e 1 8 : b r a k e p r e ss u r e b u il d - u p ch a r a ct er is t fo r t h e f r o n t 河南科技大学毕业设计 (论文 ) b r a k o f a v eh ic b r a k in g o n sp w it h I n v eh ic w it h lo w y in e r t a n d a s ho r t w h e el b a t h e ya w mo me n t b u u p ca n b e d e la y t o a w a n a v e r ag e d r i v e n o u g h r e io n t i b y s lo w in g t h e b r a k e p r es s u r e b u il d - u p o v e r th e A f o r t h e h ig h - w h e e l. Th e wh e e l o n th e su r f ac e w it h th e h ig he r f r i ct io n co ef f ic ie n t i s t h e r e f o r e, p a r t la r l y t h e b e g i n n i n g o f b r ak in g , u n d e r - b r a k an d