GB2148460A - Control apparatus - Google Patents

Abstract

A side stick controller for an aircraft for producing principal control signals for the aircraft, e.g. climb or dive and roll, comprises a housing 10, a stick member 16, mounted on a shaft 11 for linear and rotational movement, and linear and rotational position sensors 28 to 34 and 35 to 40 respectively. An arm rest 27 supports the fore-arm and has the same linear movement of the stick member 16. The liner movement is converted into rotational movement for pick-up units 34 and 34' with a helical groove in rotary shaft 29. <IMAGE>

Description

SPECIFICATION Control apparatus This invention relates to control apparatus for aircraft, and in particular but not exlusively to such apparatus for effecting principal control movements of an aircraft, for example climb or dive and roll.

It is known to provide\aircraft with control systems in which various of the aerodynamic control surfaces of the aircraft are moved by actuators which are controlled by means of control signals generated by a force stick controller. In such known controllers, a stick member is mounted on a fixed structure for pivotal movement about a central point in the fore and aft sense and in the lateral sense to provide control signals for the climb or dive sense and the roll sense respectively. However, this type of controller requires a relatively long control stick and thus contributes to a relatively large installed depth for the controller in the aircraft cockpit.

In one aspect of this invention, there is provided control apparatus for an aircraft adapted to produce signals in response to control movements, comprising a fixed housing, a manually moveable stick member supported with respect to said fixed housing for linear movement along a linear axis and angular movement about a rotational axis, linear position sensing means for sensing linear displacement of the manually movable stick member and angular position sensing means for sensing angular displacement of the manually moveable stick member.

The manually moveable stick member is preferably carried by a fixed shaft for sliding movement and angular movement with respect thereto.

The apparatus advantageously includes arm rest means adapted to support a portion of the arm of a user gripping said manually moveable stick member, said arm rest means being adapted to move axially with the manually moveable stick member, but being prevented from rotation with respect thereto.

Where the manually moveable stick member is carried by a fixed shaft for axial sliding movement, it is convenient for said member and said shaft to be magnetically interacting and for there to be winding means for being electrically driven to produce resistance to movement of said member with respect to said shaft.

Said linear position sensing means preferably includes a shaft having a helical groove provided therein and a co-operating member slideably associated therewith so that relative axial movement causes relative rotation, one of said shaft and said member being fixed against rotation and the other being free for rotation and having position encoder means associated therewith.

Said angular position sensing means preferably include a shaft rotatably carried by said fixed housing and having position encoder means associated therewith, the shaft having longitudinally extending engagement means which co-operate with complementary engagement means associated with said moveable stick member, thereby to cause rotation of said shaft on angular movement of said stick member.

In another aspect of this invention, there is provided control apparatus for an aircraft, adapted to produce signals in response to control movements, comprising: (i) a fixed housing (ii) a fixed shaft secured within said housing (iii) a manually moveable stick member slidably mounted on said shaft for linear movement along a linear axis and angular movement about a rotational axis, (iv) arm rest means, adapted to support a part of the arm of a user, being connected to said manually moveable stick member by a sleeve member which extends coaxially with respect to said shaft member surrounding a part thereof and which allows relative rotation of the manually moveable stick member relative to the arm rest means whilst preventing linear movement relative thereto.

(v) first and second generally coaxial shaft means disposed within said housing generally parallel to said fixed shaft means, each shaft being mounted for turning movement and having position encoder means associated therewith, one of said shaft means being associated with said manually moveable member so as to turn on angular movement of the manually moveable member, the other of said shaft means being associated with said arm rest means so as to turn on linear movement thereof.

Further aspects will become apparent from the following description which is by way of example only, reference being made to the accompanying drawings, in which: Figure 1 is a side section view through the centre of a side stick controller, Figure 2 is a sectional view on arrows ll-ll of the controller of Fig. 1.

The controller illustrated in the Figures is intended to be located at the side of the pilot position in the cockpit of an aircraft and to produce "climb" or "dive" signals and "roll" signals to actuate various control surfaces of the aircraft in response to control movements imparted to the controller by the pilot.

Referring to the Figures the controller comprises a housing 10 of rectangular box form which in use is attached to a fixed structural part of the cockpit of the aircraft.

A composite shaft 11 is secured in an upper part of the housing 10 by means of flanges bushes 1 2 secured to opposed end walls 13, 13' of the housing. The composite shaft 11 consists of two shafts, 14, 1 5 of similar diameter arranged coaxially end to end, shaft 14 constituting the stator of a linear stepper motor 19 and shaft 1 5 being a plane shaft.

A manually grippable stick member 16 is carried on composite shaft 11 for axial and rotational movement with respect thereto and extends through a longitudinal slot 1 7 provided in the upper wall of housing 10. The slot is dimensioned to allow axial movement of the stick member and also to allow limited angular movement with respect to the shaft 11. A brush type seal 1 8 is provided in the slot to prevent ingress of dirt.

The stick member 16 is slideably carried on the shaft 11 by means of the "mover" component 20 of the stepper motor 19, and is secured to the flanged end 21 of a sleeve member 22 which slideably surrounds shaft 11. The end of the sleeve member 22 remote from the stick member 1 6 is rotatably received by means of bearing 23 in an arm rest support member 24 and secured against axial movement with respect thereto by nut 25.

The upper end of arm rest support member 24 extends through a longitudinal slot 26 provided in the upper wall of housing 10, to carry arm rest 27. The slot 26 is dimensioned so as to allow linear movement of the arm rest 27 jointly with the manually grippable stick member 16 and includes a brush type seal 1 8. The lower portion of the arm rest support member 25 is provided with a bore in which is located a recirculating ball race 28 which engages a co-operating shaft 29 supported at its end for rotation with respect to the housing means of opposed inserts 30, located in partition wall 31 and end wall 13' respectively.

The shaft 29 is provided with a helical groove whereby linear movement of the arm rest support member and thus of the stick member 1 6 to which it is attached imparts rotational movment to the shaft. Adjacent to each end of the shaft 29 is secured coaxial pinion 32, 321 which engages a complementary pinion 33, 331 attached to the input shaft of a respective rotary pick off unit 34, 341 which generates a signal indicative of the annular position of the shaft 29, and hence the linear position of the stick member 1 6 with respect to housing 10. Pinion 32, 321 and 33, 33' are designed so as to reduce backlash in transmission of rotary movement of the shaft 29 to the pick off units 34, 341.

Referring now more particularlu to Fig. 2, the lower end of the stick member 1 6 is provided with a depending lug 35 the end of which is formed as a ground follower to locate in a longitudinal ground groove 36 provided in a further shaft 37, which is supported at its ends for rotation with respect to the housing 10 by means of opposed inserts 30, located in the end wall 1 3 of the housing and the partition wall. Adjacent each end of shaft 37 is secured a coaxial pinion 38, 38' which engages a complementary pinion 39, 391 attached to the input shaft of a respective rotary pick up unit 40, 40' which generates a signal indicative of the angular position of the shaft 37.Movement of the stick member angularly about shaft 11 causes rotational movement of shaft 37 and via pinion 38, 38' and 39, 391 rotation of the input shaft of the rotary pick off unit. Pinions 38, 38' and 39, 39' are designed so as to reduce backlash in transmission of movement of shaft 37 to pick off units 40, 401.

A series of compression springs 41, 41' (shown schematically in Fig. 2) are arranged to either side of lug 35 to provide a resistance to turning movement of stick member 1 6 on shaft 11 thus to impart a "feel" characteristic in this sense.

The upper surface 42 of housing 10 alongside slot 1 7 may be inscribed with increments of "dive" or "climb". The exposed portion of the stick member 16 may take numerous forms depending on the ancillary functions it is to perform, and control cable 43 shown in dotted lines services the control elements provided on the stick member.

Referring to the stepper motor mover 20 provided in the stick member 16 and its complementary stator shaft 14, the mover may be electrically energised to provide a "feel" characteristic, that is to provide resistance to linear movement. Stator shaft 14 need therefore extend as far as the extent of movement of mover 20, the remainder of the shaft being plain.

Operation of the controller is as follows; control demand for movements of "climb" or "dive:" result from the combined linear movement of the stick member 16 and arm rest 27, demand being effected via rotary pick off units 34, 34', linear to rotary motion being transmitted by shaft 29 and recircling ball race 28.

Roll control in transmitted solely by lateral (angular) movement of stick member 1 6 (typical up to + 10 ) and the arm rest is restrained against such movement. This movement causes rotation of shaft 37, demand being effected via rotary pick up units 40, 40'.

It will be appreciated that in the above embodiment, control signals for movement in the climb/drive and roll sense are achieved by linear movement and angular movement respectively of the stick member 16, and that the forearm of the pilot is supported by the arm rest 27 for linear movement with the stick member to assist his control movements both in the linear sense and in the angular sense. Since control signals are achieved by linear movement, it is believed that the installed depth of the side stick controller may be substantially less than that for a conventional form of side stick controller, and thus that this embodiment of controller may be substantially more compact than those of the conventional form.

Reference is directed to our UK Patent No.

2073887 in which control demands for providing a single set of control signals are achieved by means of a control stick mounted for linear movement with respect to a fixed housing.

Claims (8)

1. Control apparatus for an aircraft, adapted to produce signals in response to control movements comprising: (i) a fixed housing, (ii) a manually moveable stick member supported with respect to said fixed housing for linear movement along a linear axis and rotational movement about a rotational axis, (iii) linear position sensing means for sensing the linear position of the manually moveable member, and (iv) angular position sensing means for sensing angular displacement of the manually moveable member.

2. Control apparatus according to Claim 1, wherein said manually moveable stick member is carried by a fixed shaft member for sliding and turning movement with respect thereto.

3. Control apparatus according to Claim 1 or Claim 2, which further includes arm rest means adapted to support a portion of the arm of a user when gripping said manually moveable stick member, said arm rest means being adapted to move axially with the manually moveable stick member but being prevented from rotation with respect thereto.

4. Control apparatus according to Claim 2 wherein said manually moveable stick member and said fixed shaft member are magnetically interacting and winding means are provided for being electrically driven to produce resistance to movement of said member with respect to said shaft.

5. Control apparatus according to any one of the preceding claims, wherein said linear position sensing means includes a shaft having a helical groove provided therein and a cooperating member slideably associated therewith so that relative axial movement causes relative rotation, one of said shaft and said member being fixed and the other being free for rotation and having position encoder means associated therewith.

6. Control apparatus according to any of the preceding claims, wherein said angular position sensing means includes a shaft rotatably carried by said fixed portion and having position encoder means associated therewith, the shaft having longitudinally extending engagement means which co-operate with complementary engagement means associated with said moveable stick member.

7. Control apparatus for an aircraft, adapted to produce signals in response to control movement, comprising: (i) a fixed housing, (ii) fixed shaft secured within said housing.

(iii) a manually moveable stick member slidably mounted on said shaft for linear movement along a linear axis and angular movement about a rotational axis, (iv) arm rest means, adapted to support a part of the arm of a user, being connected to said manually moveable stick member by a sleeve member which extends coaxially with respect to said shaft member surrounding a part thereof and which allows rotation of the manually moveable stick member relative to the arm rest means whilst preventing linear movement relative thereto, (v) first and second generally coaxial shaft means disposed within said housing generally parallel to said fixed shaft means, each shaft being mounted for turning movement and having position encoder means associated therewith, one of said shaft means being associated with said manually moveable stick member so as to turn on angular movement of the manually moveable stick member, the other of said shaft means being associated with said arm rest means so as to turn on linear movement thereof.

8. Control apparatus, substantially as hereinbefore described, with reference to and as illustrated in, any of the accompanying drawings.