Torque detection apparatus for controlling a vehicle

Claim 2

In a vehicle having a drive source for driving wheels which is coupled to a transmission and right and left wheels by respective shafts having torsional stiffness for transmitting a drive torque through a differential gear, a torque detection apparatus for controlling the vehicle, comprising: drive source revolution angle detection means for detecting a revolution angle of the drive source; wheel revolution angle detection means for detecting revolution angles of the wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the differential gear to the wheels using the following expression: T.sub.-- Dr=T.sub.-- Dl=k.sub.-- Dr k.sub.-- Dl/(k.sub.-- Dr+k.sub.-- Dl) (theta.sub.-- Wr+theta.sub.-- Wl-2theta.sub.-- E/(i.sub.-- D i.sub.-- T)) wherein k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, theta -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source , i -- D is a reduction ratio of the differential gear, i -- T is a change gear ratio of the transmission, and r and I are right and left wheels, respectively.

Claim 3

In a vehicle having a drive source for driving wheels which is coupled to a transmission and right and left wheels by respective shafts having torsional stiffness for transmitting a drive torque through a differential gear and having a differential limiting mechanism for the differential gear, a torque detection apparatus for controlling the vehicle, comprising: differential limiting torque detection means for detecting a differential limiting torque; drive source revolution angle detection means for detecting a revolution angle of the drive source; wheel revolution angle detection means for detecting revolution angles of the right and left wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the differential gear to the wheels using the following expressions: T.sub.-- Dr=2k.sub.-- Dr k.sub.-- Dl{(theta.sub.-- Wr+theta.sub.-- Wl)/2-theta.sub.-- E/(i.sub.-- T i.sub.-- D)-T.sub.-- V}/(k.sub.-- Dr+k.sub.-- Dl), and T.sub.-- Dl=2k.sub.-- Dr k.sub.-- Dl{(theta.sub.-- Wr+theta.sub.-- Wl)/2-theta.sub.-- E/(i.sub.-- T i.sub.-- D)+T.sub.-- V}/(k.sub.-- Dr+k.sub.-- Dl) wherein T -- V is a differential limiting torque, k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, theta -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- D is a reduction ratio of the differential gear, i -- T is a change gear ratio of the transmission, and r and l are right and left wheels, respectively.

Claim 4

In a vehicle having a drive source for driving wheels which is coupled to a transmission and right and left wheels by respective shafts having torsional stiffness for transmitting a drive torque through a differential gear and having a differential limiting mechanism for the differential gear, a torque detection apparatus for controlling the vehicle, comprising: differential limiting torque detection means for detecting a differential limiting torque; drive source revolution angle detection means for detecting a revolution angle of the drive source; wheel revolution angle detection means for detecting revolution angles of the right and left wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the differential gear to the wheels using the following expressions: T.sub.-- Dr=2k.sub.-- Dr k.sub.-- Dl{(theta.sub.-- Wr+theta.sub.-- Wl)/2-theta.sub.-- E/(i.sub.-- T i.sub.-- D)-T.sub.-- V}/(k.sub.-- Dr+k.sub.-- Dl), and T.sub.-- Dl=2k.sub.-- Dr k.sub.-- Dl{(theta.sub.-- Wr+theta.sub.-- Wl)/2-theta.sub.-- E/(i.sub.-- T i.sub.-- D)+T.sub.-- V}/(k.sub.-- Dr+k.sub.-- Dl) wherein T -- V is a differential limiting torque, k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, theta -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- D is a reduction ratio of the differential gear, i -- T is a change gear ratio of the transmission, and r and l are right and left wheels, respectively.

Claim 5

In a vehicle having a drive source for driving wheels which is coupled to a transmission and right and left wheels by respective shafts having torsional stiffness for transmitting a drive torque through a differential gear and having a differential limiting mechanism for the differential gear, a torque detection apparatus for controlling the vehicle, comprising: revolution angle acceleration detection means for detecting a revolution angle acceleration of the drive source; differential limiting torque detection means for detecting a differential limiting torque; and torque calculation means for detecting torques, T -- D, of shafts for coupling the differential gear to the wheels using the following expressions: T.sub.-- Dr=k.sub.-- Dr(i.sub.-- D i.sub.-- T(l.sub.-- E alpha.sub.-- E)-2T.sub.-- V)/2, and T.sub.-- Dl=k.sub.-- Dl(i.sub.-- D i.sub.-- T(l.sub.-- E alpha.sub.-- E)+2T.sub.-- V)/2 wherein l -- E is an inertia moment of the drive source, alpha -- E is a revolution angle acceleration of the drive source, T -- V is a differential limiting torque, k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, i -- D is a reduction ratio of the differential gear, i -- T is a change gear ratio of the transmission, and r and l are right and left wheels, respectively.

Claim 6

In a vehicle having a drive source for driving wheels which is coupled to a transmission and right and left wheels by respective shafts having torsional stiffness for transmitting a drive torque through a differential gear and having a differential limiting mechanism for the differential gear, a torque detection apparatus for controlling the vehicle, comprising: revolution angle acceleration detection means for detecting a revolution angle acceleration of the drive source; differential limiting torque detection means for detecting a differential limiting torque; and torque calculation means for detecting torques, T -- D, of shafts for coupling the differential gear to the wheels using the following expressions: T.sub.-- Dr=k.sub.-- Dr(i.sub.-- D i.sub.-- T(l.sub.-- E alpha.sub.-- E)-2T.sub.-- V)/2, and T.sub.-- Dl=k.sub.-- Dl(i.sub.-- D i.sub.-- T(l.sub.-- E alpha.sub.-- E)+2T.sub.-- V)/2 wherein l -- E is an inertia moment of the drive source, alpha -- E is a revolution angle acceleration of the drive source, T -- V is a differential limiting torque, k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, i -- D is a reduction ratio of the differential gear, i -- T is a change gear ratio of the transmission, and r and l are right and left wheels, respectively.

Claim 7

In a vehicle having a drive source for driving wheels which is coupled to a transmission and right and left wheels by respective shafts having torsional stiffness for transmitting a drive torque through a differential gear and having a differential limiting mechanism for the differential gear, a torque detection apparatus for controlling the vehicle, comprising: revolution angle detection means for detecting a revolution angle of the drive source; revolution angle acceleration detection means for detecting a revolution angle acceleration of the drive source; wheel revolution angle detection means for detecting revolution angles of the right and left wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the differential gear to the wheels using the following expressions: T.sub.-- Dr=k.sub.-- Dr{-i.sub.-- D i.sub.-- T(l.sub.-- E alpha.sub.-- E)+2k.sub.-- Dl((theta.sub.-- Wr+theta.sub.-- Wl)/2-theta.sub.-- E/(i.sub.-- D i.sub.-- T))}/(k.sub.-- Dl-k.sub.-- Dr), and T.sub.-- Dl=k.sub.-- Dl{i.sub.-- D i.sub.-- T{l.sub.-- E alpha.sub.-- E)-2k.sub.-- Dr((theta.sub.-- Wr+theta.sub.-- Wl)/2-theta.sub.-- E/(i.sub.-- D i.sub.-- T))}/(k.sub.-- Dl-k.sub.-- Dr) wherein l -- E is an inertia moment of the drive source, alpha -- E is a revolution angle acceleration of the drive source, k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, theta -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- D is a reduction ratio of the differential gear, i -- T is a change gear ratio of the transmission, and r and l are right and left wheels, respectively.

Claim 8

In a vehicle having a drive source for driving wheels which is coupled to a transmission and right and left wheels by respective shafts having torsional stiffness for transmitting a drive torque through a differential gear and having a differential limiting mechanism for the differential gear, a torque detection apparatus for controlling the vehicle, comprising: revolution angle detection means for detecting a revolution angle of the drive source; revolution angle acceleration detection means for detecting a revolution angle acceleration of the drive source; wheel revolution angle detection means for detecting revolution angles of the right and left wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the differential gear to the wheels using the following expressions: T.sub.-- Dr=k.sub.-- Dr{-i.sub.-- D i.sub.-- T(l.sub.-- E alpha.sub.-- E)+2k.sub.-- Dl((theta.sub.-- Wr+theta.sub.-- Wl)/2-theta.sub.-- E/(i.sub.-- D i.sub.-- T))}/(k.sub.-- Dl-k.sub.-- Dr), and T.sub.-- Dl=k.sub.-- Dl{i.sub.-- D i.sub.-- T{l.sub.-- E alpha.sub.-- E)-2k.sub.-- Dr((theta.sub.-- Wr+theta.sub.-- Wl)/2-theta.sub.-- E/(i.sub.-- D i.sub.-- T))}/(k.sub.-- Dl-k.sub.-- Dr) wherein l -- E is an inertia moment of the drive source, alpha -- E is a revolution angle acceleration of the drive source, k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, theta -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- D is a reduction ratio of the differential gear, i -- T is a change gear ratio of the transmission, and r and l are right and left wheels, respectively.

Claim 9

In a direct-coupled 4WD vehicle having a drive source for driving wheels which is coupled to the wheels by respective shafts having torsional stiffness for transmitting a drive torque in such a manner that power is distributed from the drive source to the front and rear wheels through a transmission and a propeller shaft and further to right and left wheels through differential gears, a torque detection apparatus for controlling the vehicle comprising: revolution angle detection means for detecting a revolution angle of the drive source; wheel revolution angle detection means for detecting revolution angles of the four wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the front and rear differential gears to the wheels using the following expressions: T.sub.-- DFr=T.sub.-- DFl=k.sub.-- DFr k.sub.-- DFl((theta.sub.-- WFr+theta.sub.-- WFl)-2theta.sub.-- E/i.sub.-- DF i.sub.-- T)/(k.sub.-- DFl+k.sub.-- DFr), and T.sub.-- DRr=T.sub.-- DRl=k.sub.-- DRr k.sub.-- DRl((theta.sub.-- WRr+theta.sub.-- WRl)-2theta.sub.-- E/i.sub.-- DR i.sub.-- T)/(k.sub.-- DRl+k.sub.-- DRr) wherein k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, theta -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- D is a reduction ratio of the differential gear, i -- T is a chance gear ratio of the transmission, r and l are right and left wheels, respectively, and F and R are front and rear wheels, respectively.

Claim 10

In a direct-coupled 4WD vehicle having a drive source for driving wheels which is coupled to the wheels by respective shafts having torsional stiffness for transmitting a drive torque in such a manner that power is distributed from the drive source to the front and rear wheels through a transmission and a propeller shaft and further to right and left wheels through differential gears, a torque detection apparatus for controlling the vehicle comprising: revolution angle detection means for detecting a revolution angle of the drive source; wheel revolution angle detection means for detecting revolution angles of the four wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the front and rear differential gears to the wheels using the following expressions: T.sub.-- DFr=T.sub.-- DFl=k.sub.-- DFr k.sub.-- DFl((theta.sub.-- WFr+theta.sub.-- WFl)-2theta.sub.-- E/i.sub.-- DF i.sub.-- T)/(k.sub.-- DFl+k.sub.-- DFr), and T.sub.-- DRr=T.sub.-- DRl=k.sub.-- DRr k.sub.-- DRl((theta.sub.-- WRr+theta.sub.-- WRl)-2theta.sub.-- E/i.sub.-- DR i.sub.-- T)/(k.sub.-- DRl+k.sub.-- DRr) wherein k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, theta -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- D is a reduction ratio of the differential gear, i -- T is a chance gear ratio of the transmission, r and l are right and left wheels, respectively, and F and R are front and rear wheels, respectively.

Claim 11

In a direct-coupled 4WD vehicle having a drive source such as an engine or a motor for driving wheels which is coupled to the wheels by respective shafts having torsional stiffness for transmitting a drive torque in such a manner that power is distributed from the drive source to the front and rear wheels through a transmission and a propeller shaft and further to right and left wheels through differential gears, a torque detection apparatus for controlling the vehicle, comprising: revolution angle acceleration detection means for detecting a revolution angle acceleration of the drive source; wheel revolution angle detection means for detecting revolution angles of the four wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the front and rear differential gears to following expressions: T.sub.-- DFr=T.sub.-- DFl=NUMF11/DEN11(l.sub.-- E alpha.sub.-- E)+NUMF12/DEN11{i.sub.-- DF(theta.sub.-- WFl+theta.sub.-- WFr)-i.sub.-- DR(theta.sub.-- WRl+theta.sub.-- WRr)}, and T.sub.-- DRr=T.sub.-- DRl=NUMR11/DEN11(l.sub.-- E alpha.sub.-- E)+NUMR12/DEN11{i.sub.-- DF(theta.sub.-- WFl+theta.sub.-- WFr)-i.sub.-- DR(theta.sub.-- WRl+theta.sub.-- WRr)} wherein: NUMF11=i -- DF i -- DRA 2i -- T k -- DFl k -- DFr(k -- DRl+k -- DRr), NUMF12=2i -- DF k -- DFl k -- DFr k -- DRl k -- DRr, DEN11=2{i -- DR 2k -- DFl k -- DFr(k -- DRl+k -- DRr)+i -- DF 2k -- DRl k -- DRr(k -- DFl+k -- DFr)}, NUMR11=i -- DR i -- DF 2i -- T k -- DRl k -- DRr(k -- DFl+k -- DFr), and NUMR12=-2i -- DR k -- DFl k -- DFr k -- DRl k -- DRr, wherein l -- E is an inertia moment of the drive source, k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, alpha -- E is a revolution angle acceleration of the drive source, theta -- W is a revolution angle of each wheel, i -- D is a reduction ratio of the differential gear, i -- T is a change gear ratio of the transmission, r and l are right and left wheels, respectively, and F and R are front and rear wheels, respectively.

Claim 12

In a direct-coupled 4WD vehicle having a drive source such as an engine or a motor for driving wheels which is coupled to the wheels by respective shafts having torsional stiffness for transmitting a drive torque in such a manner that power is distributed from the drive source to the front and rear wheels through a transmission and a propeller shaft and further to right and left wheels through differential gears, a torque detection apparatus for controlling the vehicle, comprising: revolution angle acceleration detection means for detecting a revolution angle acceleration of the drive source; wheel revolution angle detection means for detecting revolution angles of the four wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the front and rear differential gears to following expressions: T.sub.-- DFr=T.sub.-- DFl=NUMF11/DEN11(l.sub.-- E alpha.sub.-- E)+NUMF12/DEN11{i.sub.-- DF(theta.sub.-- WFl+theta.sub.-- WFr)-i.sub.-- DR(theta.sub.-- WRl+theta.sub.-- WRr)}, and T.sub.-- DRr=T.sub.-- DRl=NUMR11/DEN11(l.sub.-- E alpha.sub.-- E)+NUMR12/DEN11{i.sub.-- DF(theta.sub.-- WFl+theta.sub.-- WFr)-i.sub.-- DR(theta.sub.-- WRl+theta.sub.-- WRr)} wherein: NUMF11=i -- DF i -- DRA 2i -- T k -- DFl k -- DFr(k -- DRl+k -- DRr), NUMF12=2i -- DF k -- DFl k -- DFr k -- DRl k -- DRr, DEN11=2{i -- DR 2k -- DFl k -- DFr(k -- DRl+k -- DRr)+i -- DF 2k -- DRl k -- DRr(k -- DFl+k -- DFr)}, NUMR11=i -- DR i -- DF 2i -- T k -- DRl k -- DRr(k -- DFl+k -- DFr), and NUMR12=-2i -- DR k -- DFl k -- DFr k -- DRl k -- DRr, wherein l -- E is an inertia moment of the drive source, k -- D is a torsional stiffness of shafts for coupling the differential gear to the wheels, alpha -- E is a revolution angle acceleration of the drive source, theta -- W is a revolution angle of each wheel, i -- D is a reduction ratio of the differential gear, i -- T is a change gear ratio of the transmission, r and l are right and left wheels, respectively, and F and R are front and rear wheels, respectively.

Claim 13

In a 4WD vehicle having a drive source for driving wheels which is coupled to the wheels by respective shafts having torsional stiffness for transmitting a drive torque in such a manner that power is distributed from the drive source to the front and rear wheels through a transmission and a center differential gear with a differential limiting gears, a torque detection apparatus for controlling the vehicle, comprising: revolution angle detection means for detecting a revolution angle of the drive source; wheel revolution angle detection means for detecting revoution angles of the four wheels; differential limitinng torque detetion means for detecting a differential limiting torque of the center differential gear; and torque calculation means for detecting torques, T 13 D, of shafts for coupling the front and rear differential gears to the wheels using the followig expressions: ##EQU19## wherein: NUMF31=I 13 DF k -- DFl k -- DFr k -- DRl k -- DRr, NUMF32=i -- CE i -- DF i --DR 2k -- DFl k --DFr (k -- DRl+k -- DRr), DEN31=i -- DE (i --DR 2 K -- DF1 k -- DFr (k -- DRl+k -- DRr)+i -- DF 2 k -- DRl k -- DRr (k -- DFl+k -- DFr)), NUM31=i -- DR k -- DFl k -- DFr k -- DRl k -- DRr, NUMR32=i -- CE i -- DF 2 i -- DR k -- DRl k -- DRr (k -- DFl+k -- DFr), wherein, i -- CE is a reduction ratio of the center differential gear, i -- D is a reduction ration of the differential gears, thet -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- T is a change gear ratio, T -- V is a differential limiting torque, k -- D is a torsional stiffness of shafts for coupling the center differential gear to the wheels, r and l are right and left wheels, respectively, and F and R are front and rear wheels, respectivedly.

Claim 14

In a 4WD vehicle having a drive source for driving wheels which is coupled to the wheels by respective shafts having torsional stiffness for transmitting a drive torque in such a manner that power is distributed from the drive source to the front and rear wheels through a transmission and a center differential gear with a differential limiting gears, a torque detection apparatus for controlling the vehicle, comprising: revolution angle detection means for detecting a revolution angle of the drive source; wheel revolution angle detection means for detecting revoution angles of the four wheels; differential limitinng torque detetion means for detecting a differential limiting torque of the center differential gear; and torque calculation means for detecting torques, T 13 D, of shafts for coupling the front and rear differential gears to the wheels using the followig expressions: ##EQU19## wherein: NUMF31=I 13 DF k -- DFl k -- DFr k -- DRl k -- DRr, NUMF32=i -- CE i -- DF i --DR 2k -- DFl k --DFr (k -- DRl+k -- DRr), DEN31=i -- DE (i --DR 2 K -- DF1 k -- DFr (k -- DRl+k -- DRr)+i -- DF 2 k -- DRl k -- DRr (k -- DFl+k -- DFr)), NUM31=i -- DR k -- DFl k -- DFr k -- DRl k -- DRr, NUMR32=i -- CE i -- DF 2 i -- DR k -- DRl k -- DRr (k -- DFl+k -- DFr), wherein, i -- CE is a reduction ratio of the center differential gear, i -- D is a reduction ration of the differential gears, thet -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- T is a change gear ratio, T -- V is a differential limiting torque, k -- D is a torsional stiffness of shafts for coupling the center differential gear to the wheels, r and l are right and left wheels, respectively, and F and R are front and rear wheels, respectivedly.

Claim 15

In a 4WD vehicle having a drive source for driving wheels which is coupled to the wheels by respective shafts hving torsional stiffness for transmitting a drive torque in such a manner that power is distributed from the drive source to the fronnt and rear wheels through a center differential gear with a differential limiting mechanism and further to right and left wheels through differential gears, a torque detection apparatus for controlling the vehicle, comprising: revolution angle acceleration detection means for detecting a revolution angle acceleration of the drive source; differential limitig torque detection means for detecting a differential limiting torque of the center differential gear; and torque calculation means for detecting torques, T -- D, of shafts for coupling the front and rear differential gears to the wheels using the the following expressions: T.sub.-- DRr=T.sub.-- DFl=(i.sub.-- T i.sub.-- CE i.sub.-- DF (I.sub.-- E alpha.sub.-- E-T.sub.-- E)-2 i.sub.-- DF T.sub.-- V) /4, T.sub.-- DRr=T.sub.-- DRl=(i.sub.-- T i.sub.-- CE i.sub.-- DR (I.sub.-- E alpha.sub.-- E-T.sub.-- E)+2 i.sub.-- Dr T.sub.-- V) /4, wherein, i -- T is a change gear ratio, i -- CE is a reduction ratio of the center differential gear, i -- D is a reduction ratio of the differential gears, i -- E is an inertia moment of the drive source, alpha -- E is a revolution angle of acceleration of the drive source, T -- E is a torque of the drive source, T -- V is a differential limiting torque, r and l are right and left wheels, respectively, and F and R are front and rear wheels, respectively.

Claim 16

In a 4WD vehicle having a drive source for driving wheels which is coupled to the wheels by respective shafts hving torsional stiffness for transmitting a drive torque in such a manner that power is distributed from the drive source to the fronnt and rear wheels through a center differential gear with a differential limiting mechanism and further to right and left wheels through differential gears, a torque detection apparatus for controlling the vehicle, comprising: revolution angle acceleration detection means for detecting a revolution angle acceleration of the drive source; differential limitig torque detection means for detecting a differential limiting torque of the center differential gear; and torque calculation means for detecting torques, T -- D, of shafts for coupling the front and rear differential gears to the wheels using the the following expressions: T.sub.-- DRr=T.sub.-- DFl=(i.sub.-- T i.sub.-- CE i.sub.-- DF (I.sub.-- E alpha.sub.-- E-T.sub.-- E)-2 i.sub.-- DF T.sub.-- V) /4, T.sub.-- DRr=T.sub.-- DRl=(i.sub.-- T i.sub.-- CE i.sub.-- DR (I.sub.-- E alpha.sub.-- E-T.sub.-- E)+2 i.sub.-- Dr T.sub.-- V) /4, wherein, i -- T is a change gear ratio, i -- CE is a reduction ratio of the center differential gear, i -- D is a reduction ratio of the differential gears, i -- E is an inertia moment of the drive source, alpha -- E is a revolution angle of acceleration of the drive source, T -- E is a torque of the drive source, T -- V is a differential limiting torque, r and l are right and left wheels, respectively, and F and R are front and rear wheels, respectively.

Claim 17

In a 4WD vehicle having a drive source for driving wheels which is coupled to the wheels by respective shafts having torsional stiffness for transmitting a drive torque in such a manner that power is distributed from the drive source to the front and rear wheels through a center differential gear with a differential limiting mechanism and further to right and left wheels through differential gears, a torque detection apparatus for controlling the vehicle, comprising: revolution angle detection means for detecting a revolution angle of the drive source; revolution angle acceleration detection means for detecting a revolution angle acceleration of the drive source, and; wheel revolution angle detection means for detecting revolution angles of the four wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the front and rear differential gears to the wheels using the the following expressions: ##EQU20## wherein: NUM51=i -- T i -- CE 2 I -- DF i -- DR 2 k -- DFl i -- DFr (k -- DRl+k -- DRr), NUMF52=2 i -- DF k -- DFl k -- DFr k -- DRl k -- DRr, DE51=2 i -- CE (i -- Dr 2 K -- DFl k --DFr (k -- DRl+k --DRr )-i --DF 2 k -- DRl k -- DRr (k -- DFl+k -- DFr)), NUMR51=i -- T i -- CE 2 I -- DF 2 i -- DR k -- DRl i -- DRr (k -- DFl+k -- DFr), and NUMR52=2 i -- DR k -- DFl k -- DFr k -- DRl k -- DRr, and wherein, i -- E is an inertia moment of the drive source, alpha -- E is a revolution angle of acceleration of the drive source, T -- E is a torque of the drive source, i -- CE is a reduction ratio of the center differential gear, i -- D is a reduction ratio of the differential gears, theta -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- T is a change gear ratio, k -- D is a torsional stiffness of shafts for coupling the center differential gear to the wheels, r and l are right and left wheels, respectively, and F and R are front and rear wheels, respectively.

Claim 18

In a 4WD vehicle having a drive source for driving wheels which is coupled to the wheels by respective shafts having torsional stiffness for transmitting a drive torque in such a manner that power is distributed from the drive source to the front and rear wheels through a center differential gear with a differential limiting mechanism and further to right and left wheels through differential gears, a torque detection apparatus for controlling the vehicle, comprising: revolution angle detection means for detecting a revolution angle of the drive source; revolution angle acceleration detection means for detecting a revolution angle acceleration of the drive source, and; wheel revolution angle detection means for detecting revolution angles of the four wheels; and torque calculation means for detecting torques, T -- D, of shafts for coupling the front and rear differential gears to the wheels using the the following expressions: ##EQU20## wherein: NUM51=i -- T i -- CE 2 I -- DF i -- DR 2 k -- DFl i -- DFr (k -- DRl+k -- DRr), NUMF52=2 i -- DF k -- DFl k -- DFr k -- DRl k -- DRr, DE51=2 i -- CE (i -- Dr 2 K -- DFl k --DFr (k -- DRl+k --DRr )-i --DF 2 k -- DRl k -- DRr (k -- DFl+k -- DFr)), NUMR51=i -- T i -- CE 2 I -- DF 2 i -- DR k -- DRl i -- DRr (k -- DFl+k -- DFr), and NUMR52=2 i -- DR k -- DFl k -- DFr k -- DRl k -- DRr, and wherein, i -- E is an inertia moment of the drive source, alpha -- E is a revolution angle of acceleration of the drive source, T -- E is a torque of the drive source, i -- CE is a reduction ratio of the center differential gear, i -- D is a reduction ratio of the differential gears, theta -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- T is a change gear ratio, k -- D is a torsional stiffness of shafts for coupling the center differential gear to the wheels, r and l are right and left wheels, respectively, and F and R are front and rear wheels, respectively.

Claim 19

In a vehicle having a drive source for driving wheels which is coupled to right and left wheels by respective shafts having torsional stiffness for transmitting a drive torque through a differential gear, a torque detection apparatus for controlling the vehicle, comprising: revolution angle detection means for detecting a revolution angle of the drive source; differential gear revolution angle detection means for detecting a revolution angle of the differential gear on a propeller shaft side of said differential gear; and torque calculation means for detecting torques, T -- D, of shafts for coupling the differential gear to the wheels using the the following expression: t.sub.-- Dr=T.sub.-- Dl=1/2 k.sub.-- P i.sub.-- D (theta.sub.-- P-theta.sub.-- E / i.sub.-- T) wherein, k -- P is the torsional rigidity of the propeller shaft, i -- D is a reduction ratio of the differential gear, theta -- P is a revolution angle of the propeller shaft, theta -- E is a revolution angle of the drive source, i -- T is a change gear ratio and r and l are right and left wheels, respectively.

Claim 20

In a vehicle having a drive source for driving wheels which is coupled to right and left wheels by respective shafts having torsional stiffness for transmitting a drive torque through a differential gear, a torque detection apparatus for controlling the vehicle, comprising: revolution angle detection means for detecting a revolution angle of the drive source; differential gear revolution angle detection means for detecting a revolution angle of the differential gear on a propeller shaft side of said differential gear; and torque calculation means for detecting torques, T -- D, of shafts for coupling the differential gear to the wheels using the the following expression: t.sub.-- Dr=T.sub.-- Dl=1/2 k.sub.-- P i.sub.-- D (theta.sub.-- P-theta.sub.-- E / i.sub.-- T) wherein, k -- P is the torsional rigidity of the propeller shaft, i -- D is a reduction ratio of the differential gear, theta -- P is a revolution angle of the propeller shaft, theta -- E is a revolution angle of the drive source, i -- T is a change gear ratio and r and l are right and left wheels, respectively.

Claim 21

A torque detection apparatus for controlling a vehicle according to any one of claims 1-10, wherein said torque calculation means resets wheel revolution angles and a revolution angle of the drive source to "0" when it is determined from a state of the vehicle that torques of the shafts are "0".

Claim 22

A torque detection apparatus for controlling a vehicle according to any one of claims 1-10, which further comprises change gear ratio detection means and said torque calculation means for calculating torques of shafts coupled to the wheels using a detected change gear ratio, i -- T.

Claim 23

A torque detection apparatus for controlling a vehicle according to any one of claims 1-10, wherein said torque calculation means calculates twisting torques T -- D of shafts coupled to the wheels using an estimated change gear ratio, I -- T*, calculated using the following expression, in place of the change gear ratio I -- T: I.sub.-- T*=2theta.sub.-- E/i.sub.-- D/(theta.sub.-- Wr+theta.sub.-- Wl) where theta -- W is a revolution angle of each wheel, theta -- E is a revolution angle of the drive source, i -- D is a reduction ratio of the differential gear, and r and l are right and left wheels, respectively.

Claim 24

A torque detection apparatus for controlling a vehicle according to any one of claims 1-10, wherein said torque calculation means performs high-pass filtering of calculated twisting torque values of shafts coupled to the wheels.

Claim 25

A torque detection apparatus for controlling a vehicle according to any one of claims 1-10, wherein said torque calculation means calculates torques of shafts in synchronism with the revolution of the drive source and a revolution system.

Claim 26

A torque detection apparatus for controlling a vehicle according to any one of claims 1-10, wherein said drive source is coupled to a transmission, the apparatus further comprising shaft revolution angle detection means for detecting a revolution angle of any one of shafts disposed between input of the differential gear and the transmission, said torque calculation means calculating twisting torques of shafts coupled to the wheels using the revolution angle of any one of the shafts disposed between input of the differential gear and the transmission.