AU780975B2

AU780975B2 - Electric carrier with a motor controlled by correlative positions

Info

Publication number: AU780975B2
Application number: AU50129/01A
Authority: AU
Inventors: Gordon Liao
Original assignee: Unique Product and Design Co Ltd
Current assignee: Unique Product and Design Co Ltd
Priority date: 2001-06-05
Filing date: 2001-06-05
Publication date: 2005-04-28
Anticipated expiration: 2021-06-05
Also published as: AU5012901A

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Name of Applicant: Actual Inventor Address for service is: Unique Product Design Co., Ltd Gordon Liao WRAY ASSOCIATES 239 Adelaide Terrace Perth, WA 6000 Attorney code: WR Invention Title: Electric Carrier with a Motor Controlled by Correlative Positions Details of Associated Provisional Application No(s): The following statement is a full description of this invention, including the best method of performing it known to me:- TITLE: CARRIER WITH A MOTOR CONTROLLED BY CORRELATIVE POSITIONS

BACKGROUND

This invention relates to a carrier having a drive motor controlled by a correlative position sensor which is able to sense the movement of a driver (such as a person) whereby the speed of the carrier is controlled by changing of the relative position of the driver and the carrier and whereby the speed of the carrier may be altered in accordance with the speed of the driver. The carrier may have application in a wide variety of situations.

Generally speaking, conventional carriers having a motor which is controlled by the relative position of a driver have two ways of controlling the movement of the carrier 15 which comprise, an open route and a closed route.

S" The open route control, as shown schematically in Fig. 1, has a controller for activating a motor, which directly drives the carrier. This form of control is simple 2. and of low cost, but is limited in its scope. For example, if the carrier is a car 20 running on land, the car can run very smoothly on a flat road, with the speed controlled by a controller monitoring the movement of the car, but when the car encounters on an incline or decline, the motor cannot meet demand of maintaining the desired speed while the car is negotiating the incline or decline. Thus, the open route control mode is only suitable in an environment of little change or and where it is not necessary to accommodate for differing conditions.

As for the closed route control mode, as shown schematically at Fig. 2, this arrangement includes speed meter which is added to the open route control mode as shown at Figure 1. In this arrangement the speed meter tests the speed of the motor and feeds the data to the controller controlling the motor so that the speed of the motor may be adjusted automatically to obtain stabilized speed of the motor.

However, though the closed route control mode can guarantee to control the output of the motor, the object being controlled is the motor, and not the carrier itself. In -2this circumstance the rigidity of the drive (such as the gap between gears) and lead characteristics of the carrier may not conform with the standards set for the controller and this can result of a high degree of error. Attempts to minimize such errors can prove to not be cost effective.

SUMMARY OF THE INVENTION This invention has been devised to provide a carrier having a motor controlled by the relative position between the carrier and driver (such as a driven vehicle or a person), whereby the speed of the carrier can be synchronous with that of the driver,.

The main feature of the invention is a driver and a sensor controlled by the relative O displacement between the carrier and the driver, a controller activated by the signal produced by the sensor, a motor controlled by the controller, and an carrier driven by the motor. When the relative position of the carrier and the driver changes, the sensor immediately senses it and sends signal to the controller, which then controls the speed of the carrier to be increased or decreased to adjusting the speed of the carrier that of the driver. Thus this kind of structure can permit the carrier move with the driver and has application in a number of industries.

Accordingly the invention resides in a carrier driven by a motor, the operation of the electric motor being controlled through a control comprising a reference member supported from a body associated with a carrier to be movable relative to the body, the reference member being adapted to be associated with a driver which is able to apply a force to the reference member to cause it to move relative to the body, the reference member having a neutral position relative to the body, a sensor adapted to sense the position of the reference member relative to the body, a controller adapted to control the operation of the motor, the sensor adapted to provide an output to the controller corresponding to the relative position of the reference member to the body, wherein when said reference member is in said neutral position no force is applied to the reference member by the driver and the motor is inactive.

According to a preferred feature of the invention a biasing means is provided to bias the reference member to the neutral position.

According to a preferred feature of the invention in use the driver is intended to be a driven vehicle.

According to a preferred feature of the invention in use the reference member comprises a handle and/or is associated with a handle where the driver comprises a 10 person who is able to activate the carrier through the handle. According to a preferred feature of the invention the carrier comprises a cart or trolley. According to a preferred feature of the invention the carrier comprises a golf cart.

According to a preferred feature of the invention the carrier comprises a cycle and the reference member comprises a circular element associated with a pedal and S* 15 where the driver comprises a person who is able to activate the carrier through the movement of the pedal.

o According to a preferred feature of the invention the carrier comprises a wheel chair.

According to a preferred feature of the invention the sensor comprises an electrical brush element which is movable over a conductive surface. According to a preferred feature of the invention the conductive surface comprises a printed circuit.

According to a preferred feature of the invention the brush element comprises a carbon brush.

According to a preferred feature of the invention the sensor comprises a -4magnetically activated element.

According to a preferred feature of the invention the sensor comprises a photo sensitive element.

The invention will be more be more fully understood in the light of the following description of several specific embodiments.

BRIEF DESCRIPTION OF DRAWINGS The description is made with reference to the accompanying drawings of which: Figure 1 is a block flow chart of a conventional open route control; Figure 2 is a block flow chart of a conventional closed route control; .o 10 Figure 3 is a block flow chart of a controlling mode of an carrier with a motor controlled by the relative positions there between in accordance with the present *0 invention; Figure 4 is a schematic diagram of a first embodiment; S. Figure 5 is a partial perspective view of a second embodiment of the present S 15 invention, showing the handle of a golf cart being displaced outwardly form the cart; oo** Figure is a partial perspective view of a second embodiment of the present invention, showing the handle of a golf cart being displaced inwardly form the cart;; 0 0 Figure 7 is a schematic illustration of a first form of the position reference member •and sensor of the second embodiment; Figure 8 is a representation of the various critical positions available between the position reference member and sensor of Figure 7; Figure 9 is a schematic illustration of a second form the position reference member and sensor of the second embodiment; Figure 10 is a representation of the various critical positions available between the position reference member and sensor of Figure 9; Figure 11 is a schematic illustration of a third form of the position reference member and sensor of the second embodiment; Figure 12 is a representation of the various critical positions available between the position reference member and sensor of Figure 11; Figure 13 is a schematic illustration of a fourth form of the position reference member and sensor of the second embodiment; Figure 14 is a representation of the various critical positions available between the position reference member and sensor of Figure 13; Figure 15 is a schematic illustration of a fifth form of the position reference member and sensor of the second embodiment; Figure 16 is a representation of the various critical positions available between the position reference member and sensor of Figure 13; Figure 17 is a graphical representation of the speed set according to one response parameter for the first form position reference member and sensor shown in Fig. 7; Figure 18 is a graphical representation of the speed set according to another response parameter for the first form position reference member and sensor shown in Fig. 7; Figure 19 is a graphical representation of the speed set according to one response parameter for the second form position reference member and sensor shown in Fig.

9; Figure 20 is a graphical representation of the speed set according to one response 20 parameter for the first form position reference member and sensor shown in Fig. 11; Figure 21, is a side view of the third embodiment showing the present invention applied to a bicycle for controlling its speed; Figure 22 is a magnified side view of the fourth form of position reference member and sensor shown in Fig. 13 applied to the third embodiment of Figure 21; Figure 23 is a view of a fourth embodiment showing the present invention applied to a wheelchair for controlling its speed; Figure 24 is a front view of an array of magnetic switches and a magnet which are used as a sensor and position reference member in the fourth embodiment of Fig.

23; Figure 25 is a side view of the array of magnetic switches and magnet which are used as a sensor and position reference member in the fourth embodiment of Fig.

23; Figure 26 is a representation of the various critical positions available between the position reference member and sensor of Figures 24 and Figure 27 is a perspective view of an arrangement for supporting the sensor and position reference member of the first and second embodiments of Figures 4, 5 and 6; Figure 28 is a perspective view of an arrangement for supporting the sensor and position reference member of the fourth embodiment of Figure23; and Figure 29 is a side view of Fig. 28.

S°DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENTS The first embodiment as shown in Fig. 4, includes a vehicle as a driver 10, another vehicle as a carrier 20, a position reference member 40 located between the driver 15 10 and the carrier 20, a sensor 41 on the position reference member 40, a controller receiving signal from the sensor 41, and a motor on the carrier 20 and controlled by the controller. The sensor 41 senses the relative position of the carrier 20 and the driver 10, transmits a signal to the controller, which then controls the speed of the motor according to the relative position between carrier 20 and the driver 20 When the driver 10 moves forward, the sensor 41 transmits a signal to the controller to cause the motor to be activated to move the carrier 20 towards the driver.

According to the first embodiment, the carrier 20 is subordinate to the driver, and when the relative position between the driver 10 and the carrier 20 changes, the sensor 41 at once senses the change, sends signal to the controller which then activates the motor to re-establish the desired relative position and as a result the speed of the driver and the carrier are substantially synchronous. Although the carrier can be considered to be a load for the driver, the carrier does not make up a load of the driver since it is driven independently. For example, the sensor, the controller, the motor may be such as to be used in the preferred embodiments described below.

Figs. 5 and 6 illustrate a second embodiment of the invention which has application -7to a golf cart and comprises a handle 31 which can be grasped by the person using the cart and is slidably supported from a portion 30 whereby the person the driver) can control the speed of the golf cart through the handle in that the relative displacement of the handle on the portion will control the motor of the cart. The embodiment includes a position reference member 40 (such as a carbon brush, a magnet, a photosensitive gate, a metal, etc.) supported form the handle 31 or the portion which is slidable over a sensor 41 (such as a printed electric circuit, a magnetic switch, a photosensitive switch, or a metal sensor) which is supported from the portion 30 or handle 312 respectively as shown in Figs. 7 and 8 whereby the sensor is able to sense the position of the position reference member 40 on the sensor 41 and provide a signal to a controller 42 which in turn controls an electric motor on the cart to move the cart in accordance with the position of the position reference member 41 on the sensor 40. If in the arrangement shown at Fig. 7 is one where the position reference member 40 is considered as a carbon brush, and 1 5 the sensor 41 a copper foil, and the carbon brush is connected to ground GND. If the controller 42 has three contact points BIT2, BIT1, BITO for sensing the carbon .0.00: S°brush, and the carbon brush is designed to contact the copper foil, with the contact 0-0. !point being low or high the three contact points may have the five conditions (011), (001), (101), (100), and (110) as shown in Fig. 8, for the carbon brush being at 5 different positions on the sensor. Consequently the controller has five output S•signals for the motor and these outputs are effected by relative movement of the -position reference member 40 over sensor 41 as a result of relative displacement of the handle 31 on the portion eq..

O According to various embodiments the sensor 41 may comprise many different configurations, and provide any number of outputs. Examples of such embodiments are shown in Figs. 9, 11 13 and 15 and may present more than five controlling conditions to increase and decrease the speed, as shown in Figs. 10, 12, 14 and 16. As shown in Fig. 13, the sensor 41 may be made be curved and still have five outputs to increase or decrease the speed, as shown in Fig. 14. As in shown at Figs 17 and 18, in which the horizontal axis represents time T and the vertical axis represents speed V, if the manner in which the controller responds when a user pulls the handle 31 of the cart can vary. As shown in Fig. 17, the motor of the electric golf car can be activated slowly or as shown in Fig. 18, the motor can be activated rapidly. Therefore the sensitivity of the control may be such a that the response by the motor to a change in condition being sensed can be -8varied to cause the motor to be driven slowly or quickly to a change in speed of the user according to the desires of the user.

The, control of the aforesaid output signal to the motor can be accomplished by means of a microprocessor, with a very high accuracy. At the same time, the micro processor can perform changes to accommodate for other parameters such as the response parameter as shown in Figs. 17, and 18, and variations in the slope of the ground. In the case of a cart needing soft start may use the response parameter shown in Fig. 17, and a cart needing a large start torque may use the response parameter shown in Fig. 18.

In addition, the contact points can be used to control clockwise or counterclockwise rotation of the motor. This is illustrated in the embodiment shown in Fig. 9, wherein the four contact points provide ten conditions, (0111), (0011), (1011), (1001), (1101), 15 (1100), 1000), (11010), (0010), (0110). If the lowest bit BITO being low 0 is used for controlling two directional motion, its accelerating curve is shown in Fig. 19, where the positive portion and negative portions of the vertical axis represent clockwise and counterclockwise rotation of the motor respectively.

20 If the controller has five contact points for sensing the position of the carbon brush as shown in Figs. 11 and 15, the five points can provide for nine conditions, (01111), .(00111), (10111), (10011), (11011), (11001), (11101), (11100), and (11110) and the setting of the directional parameter for controlling clockwise and counterclockwise rotation of the motor in association with the desired of the acceleration curve is represented in Fig. If the driver is a person, (referring to Fig. 3 also) the golf cart can change the speed of the motor as in order that the cart will travel at the same speed as the user.

In the case of the third embodiment shown in Figs. 21 and 22, the speed controlling modes in the second embodiment of the invention also can apply to a circular movement by the use of the fourth or fifth form of the position reference member and sensor as shown in Fig. 13 or 15. For example, the circular movement control can be applied to a bicycle 60, utilizing a relative positioning of a pedal disc 61 and a disc 62 which rotate together with the motor where the circular movement of the pedal disc 61 send an output to drive the motor in the multi-stage speed increasing and decreasing mode as shown in Figs. 14 and 16. In this embodiment the motor does not need counterclockwise rotation, as a bike runs only forward. Therefore the assistance by the motor can provide a supplementary drive for a bicycle.

A fourth embodiment as shown at Figures 23, 24 and 25 comprises a variation of the third embodiment and has application to a wheelchair 7, which has two hand-pushed wheels 70, two rolling wheels 71, two fixed discs 72, and two control discs 73 located between the rolling discs 71 and the fixed discs 72. The relative position of the fixed discs 72 and the control discs 73 is shown in Fig. 24. The five contact points of the previous embodiments are replaced by five switches such as 15 non-contact magnetic switches on the fixed discs 72 which are turned on by a magnet 74 approaching the switches where the magnet 74 is be placed appropriately on the control discs 73 as shown in Figs 24 and 25. The magnetic switches provide has five switching contact) points and the control discs 73 in Fig. 24 are a biased to a static position relative to the corresponding fixed discs, S" 20 different magnets 74 can activate different switches to turn on. As a result only S°none or one or two magnetic switches can be activated by the magnet may be turned on as a result of the relative angular displacement of the switches. The differing conditions for the available outputs are shown in Fig. 26 for effecting differing degrees of speed control.

S As can be understood from the aforesaid description the second third and fourth embodiments shown at Figs. 5, 21 and 23 show the manner in which a driver (which may comprise a person) controls the speed of the carrier, in the manner shown schematically at Fig. 3. In the case of the driver being a person they can depending upon their capacity of the driver set the response parameter according to their desires. Figure 27 illustrates a control arrangement which applies to each of the first and second embodiments shown in Figs. 4 and 5. If the arrangement is set in an inactive mode, the person (or the driver 10) causes the carrier 20 e.g. the golf cart, or the bicycle or the wheel chair) the hand-moved wheels 70 of the wheelchair) to be moved by the person alone. In order to attain this, the position reference member 40 (such as a carbon brush) is fixed relative to the sensor. If the arrangement is set at a fully active mode the carrier is fully responsive relative to the movement of the driver. The arrangement also provides a range of intermediate modes of activity through a biasing force which is applied via a spring 80 between the support for the position reference member 40 and the support for the sensor 41 whereby the pulling or pushing force of a person is transmitted to the carrier 20 via the spring 80. In the case where the spring 80 is set to a limitlessly large elasticity, the position reference member 40 remains fixed relative to the sensor 41 and consequently the motor does not operate, and therefore the carrier 20 is completely moved by the driver and takes the form of a traditional towed or pushed vehicle. Alternatively if the spring 80 is set to a limitlessly small elasticity, the position reference member 40 is totally controlled by the driver 10, but no force is applied by the driver 10 to the carrier 20, which is moved completely by the motor and thus becomes a fully powered vehicle. Therefore by choosing the appropriate 15 spring strength changing the spring coefficient K of the springs 80) one can vary the degree of the burden of the carrier is to be borne by the driver. By a similar arrangement as shown at Figures 28 and 29 the pushing wheels 70 of the *wheelchair shown in Fig. 29 may be considered to be the driver 10, and the rolling wheels 71 to be the carrier 20, and the same driving effect will be obtained.

In the arrangement as shown in Fig. 27 the pressure applied by the spring 80 can be set to a desired value by adjusting its spring coefficient). This is achieved :o:through, a threaded rod 81 with the opposite ends provided with a right-hand threads 81A and a left-hand threads 81B, where the left hand and the right hand 25 thread 81B and 81A respectively carry a front and a rear stop plate 90 and 91 respectively and the spring is retained there between. When the threaded rod 81 is turned, the stop plates 90, 91 are moved axially towards or away from each other to vary the degree of compression of the springs 80. With this design, a user can adjust the degree of assistance desired from the motor as required.

It should be emphasized that the central ideology of the present invention is to provide an arrangement where the movement of a carrier by a driver can be set according to the desires of the situation between one where the driver bears none of the burden of moving the carrier and one where the driver can bear the total burden of moving the carrier -11- It should be appreciated that the scope of the invention is not to be limited by the description of the embodiments of the invention which have been described above and that various modifications may be made within the scope of the following claims.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

S

oO. i oo -12-

Claims

1. A carrier driven by a motor, the operation of the electric motor being controlled through a control comprising a reference member supported from a body associated with a carrier to be movable relative to the body, the reference member being adapted to be associated with a driver which is able to apply a force to the reference member to cause it to move relative to the body, the reference member having a neutral position relative to the body, a sensor adapted to sense the position of the reference member relative to the body, a 10 controller adapted to control the operation of the motor, the sensor adapted to provide an output to the controller corresponding to the relative position of the o*o* reference member to the body, wherein when said reference member is in said neutral position no force is applied to the reference member by the driver and S: the motor is inactive. 15

2. A carrier as claimed at claim 1 wherein a biasing means is provided to bias the reference member to the neutral position.

3. A carrier as claimed at claim 1 or 2 wherein in use the driver is intended to be a driven vehicle.

4. A carrier as claimed at claim 1 or 2 wherein in use the reference member comprises a handle and/or is associated with a handle where the driver comprises a person who is able to activate the carrier through the handle.

A carrier as claimed at claim 4 wherein the carrier comprises a cart or trolley.

6. A carrier as claimed at claim 4 or 5 wherein the carrier comprises a golf cart. -13-

7. A carrier as claimed at claim 1 or 2 wherein the carrier comprises a cycle and the reference member comprises a circular element associated with a pedal and where the driver comprises a person who is able to activate the carrier through the movement of the pedal.

8. A carrier as claimed at claim 1 or 2 wherein the carrier comprises a wheel chair.

9. A carrier as claimed in any one of the preceding claims wherein the sensor comprises an electrical brush element which is movable over a conductive surface.

10. A carrier as claimed at claim 9 wherein the conductive surface comprises a printed circuit. oo•0°

11. A carrier as claimed at claim 9 or 10 wherein the brush element comprises a carbon brush.

S12. A carrier as claimed at any one of claims 1 to 8 wherein the sensor comprises a magnetically activated element.

13. A carrier as claimed at any one of claims 1 to 8 wherein the sensor comprises a photo sensitive element.

14. A carrier substantially as herein described with reference to the accompanying drawings. Dated this day of Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant -14-