GB2130405A - Electronic calculator - Google Patents

Abstract

To save power a calculator includes a double microprocessor system, one system 5 controlling the other more powerful, and therefore more power-consuming, system 14 which, when not needed, is maintained 'asleep'. Power is supplied to the second system 14 via a switch 19. <IMAGE>

Description

SPECIFICATION Portable electronic apparatus For aircraft flight planning, use is made of what is known as an 'ODM' (Operator's Data Manual) which is a collection of a considerable amount of data usually in graphical form relating various characteristics of a particular aircraft. However, as aircraft become more and more complex the data required for flight planning becomes less conveniently handled manually and the planning process itself becomes more complex. For example, just to calculate the amount of fuel likely to be used in executing a relatively simple manoeuvre, such as cruising level for a particular distance, one might have to make a series of interpolations from graphs respectively relating mass, drag, altitude and velocity of the aircraft, the cruise distance and atmospheric temper- ature to the rate of use of fuel.For modern aircraft, further variables such as wing sweep may have to be taken into account.

According to one aspect of the invention, there is provided portable electronic apparatus for use in flight planning for an aircraft, the apparatus comprising manual data entry means, store means containing performance data associating predetermined values of a plurality of operating parameters for said aircraft and corresponding values of interrelated operating parameters for said aircraft, calculator means connected to said store means and said manual data entry means and operable for receiving via the manual data entry means an instruction selecting one of a plurality of predetermined manoeuvres to be carried out by the aircraft and manually entered values of variable and/or controllable ones of said operating parameters, the calculating means being further operable for calculating, by interpolation between said predetermined values contained in the store means, values of operating parameters including fuel used and time and/or distance taken, associated with the manually entered values and the selected manoeuvre, and the apparatus further including display means for displaying said calculated values.

Preferably the calculator means, data entry means and store means are operable to enable an operator to indicate, via the data entry means, acceptance of a particular manoeuvre and associated calculated parameter values whereupon the calculator means stores these values cumulatively in said store means and then the operator can cause parameters for another manoeuvre to be calculated and running totals of parameter values associated with the two manoeuvres to be displayed.

The above-mentioned store means may have to carry a large amount of information - correspondingly it may require a large capacity and substantial power to drive it. Accordingly, if the apparatus is battery powered which is desirable for portability, the battery life if somewhat reduced. It will be appreciated that this problem arises not just in apparatus for use in flight planning but also in portable apparatus for performing other kinds of calculations on the basis of substantial amounts of data.

Accordingly a second aspect of the invention resides in portable apparatus for storing data and making calculations on the basis of that data, particularly but not exclusively for use in aircraft flight planning, wherein the apparatus comprises data entry means, a first microprocessor system including first calculator means and first storage means for storing programme information associated with the first calculator means and, under the control of the first calculator means, for storing data entered via the data entry means, and a second microprocessor system including second calculator means and second storage means for storing programme information associated with the second calculator means and, under the control of the second calculator means, for storing data received from the first microprocessor system, the apparatus further comprising switch means one side of which is connected to the second microprocessor system and the other side of which is connectible, during use of the apparatus, to a power source, and the first microprocessor system being operable for receiving and temporarily storing data as it is entered via the entry means, for determining when such data is to be transferred to the second microprocessor system, and then and only then for causing said switch means to become conductive and for transferring said temporarily stored data to the second microprocessor system.

Preferably the first calculator means is of CMOS construction for low-power consumption while the first store means includes some CMOS random access memory capacity for temporarily storing entered data and sufficient permanent storage capacity for the programme information. Since the main task of the first calculator means is simply to decide when the second microprocessor system is to be woken-up so to speak, it may have relatively little calculation capacity.

The second calculator means and the second store means will generally have a very much greater capacity than the first calculator and store means.

In order that the second microprocessor system may retain variable data even when it is not actually being used, the second store means preferably comprises some CMOS random access capacity which is supplied with power other than by way of the aforementioned switch means. Thus, this RAM part of the second store means remains powered while the second calculator means and the rest of the second store means, consisting of permanent storage devices such as programmable read only memory chips (PROM's) and containing the programme information for the second calculator, are powered up only when required to perform an operation.

For a better understanding of the invention reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a plan view of the control panel of an embodiment of portable apparatus for use in aircraft flight planning, Figure 2 is a simplified circuit diagram of the Figure 1 apparatus.

Referring to Figure 1,the apparatus includes a keypad 1 having a series of press-buttons many of which have two functions as annotated above and below the relevant button, selection of the upper and lower case functions is determined by operation of the button marked 'upper' at the top left corner of the keypad as shown in the drawing. Using the keypad, an operator is able to select certain predetermined manoeuvres to be performed by a particular aircraft and enter certain parameter values whereupon, by way of alpha-numeric displays 2 above the keypad, other parameters of a nature which were previously calculated by complex manual interpolation from graphs and tables in the aforementioned 'ODM', may be obtained. The annotations shown, and hence the operations performable, will be familiar to those skilled in the art.By way of example, however, the flight planner may wish to obtain information concerning take-off of an aircraft. For this, he might press the normal take-off button marked 'Normal T.O.' and then enter, via the value entry buttons to the right-hand side of the keypad and marked with the appropriate digits, various input values of parameters such as the mass of the aircraft (which of course varies with the load carried), drag, air temper- ature and the height and length of the runway. Then, by use of the appropriately annotated buttons, the flight planner can display various limiting values such as the maximum take-off weight, rotation and lift-off speeds, and ground roll and 50' above ground distances.Preferably, the apparatus is such that, on pressing a manoeuvre button, there will be displayed automatically by the alpha-numeric display, the parameters which are required to be entered. For example, if the take-off button is pressed, and no air temperature value has yet been entered, the display will indicate this and then, when that value has been entered, will go on to indicate in turn any other parameter values still required.

As shown in Figure 2, the keypad 1 is connected via a keyboard encoder 3 to a port 4 which is also connected to the alpha-numeric display system 2 and to a first microprocessor system 5. The function of the encoder 3 is to produce appropriate encoded signals in response to operation of the keypad while the function of the port 4 is to direct signals between the encoder 3, display system 2 and the microp rocessorsystem as required under the control of the microprocessor system. This first microprocessor system 5 comprises a calculator chip 6, a programmable read only memory arrangement 7, a random access memory arrangement 8 and an address latching arrangement 9 interconnected with each other and to port 4 by way of multiple-line buses 10.

The system is powered by a battery driven power supply 11 as are the keypad 1, encoder 3 and port 4.

The encoder and microprocessor system are constructed for minimum power consumption and to that end the chip 6, encoder 3, port 4 and RAM arrangement 8 are of CMOS construction. The first microprocessor system 5 is connected via two interface ports 12 and 13 with a second microprocessor system 14 which includes a high capacity calculator chip 15 and programmable read only memory 16 along with a random access memory 17 and address latching arrangement 18. Calculator chip 15, memory 16, address latches 18 and port 13 are powered via a switched regulator 19 which is controlled by the microprocessor system 5 so that these items are only powered when required to perform an operation. So that the second system 14 can hold information in its random access memory 17, this item is driven by the unswitched supply 11 and is of CMOS construction to give low power consumption.

The apparatus shown is made up of commercially available integrated circuit components. By way of example, the calculator 6 may be an IM6100 CMOS microprocessor, the ports 4 and 12 may be 6103 CMOS ports, calculator 15 an 8086 16 bit microprocessor and the port 13 may be an Intel 8255. The memories 7 and 16 may comprise sets of 2732 UV erasable PROM's giving capacities of say 4K and 120K Bytes respectively. Memories 8 and 17 may be made up of sets of HM 6514 CMOS RAM's to give capacities of say 12K bits and 4K Bytes respectively.

The programme information for calculator 15 and data representing relationships between various performance parameters for a particular aircraft are stored in the PROM memory 16. The data is stored in the form of look-up tables made up of selected numbers of points of curves representing the relationships and the programming is such that, when values other than the ones in the tables are entered, calculation is done on the basis of interpolation from those in the tables. Such programming is relatively conventional and within the scope of those skilled in the art.

The programme information for the calculator 6 is contained in the memory 7. Calculator 6 senses operation of keypad 1 and stores incoming data in memory 8. It also causes the display system 2 to indicate any information which is required for a particular manoeuvre but which has not been entered by the time the relevant manoeuvre button of the keypad is pressed. When this button is pressed and the required information entered, the calculator 6 switches on the power to the calculator 15 and PROM 16 and transfers the data, column by column, through port 12 to port 13. Ports 12 and 13 include 'handshake' control connections through which port 12 indicates to port 13 that a data column is available for transfer and port 13 indicates to port 12 when it has received that column and is ready to receive another.

When the requisite calculations have been made in microprocessor system 14, the resultant is transferred back via ports 12 and 13 to the system 5 which controls port 4 so as to display this data. As shown in Figure 1, the button next to the aforementioned upper and lower case selection button is labelled 'Accept'. Operation of this button indicates acceptance of a particular manoeuvre by the flight planner whereupon the second microprocessor system is caused to store certain parameters, such as the amount of fuel expended for a manoeuvre, cumulatively in its memory 17. Thereby, a running total of these parameters for a series of consecutive manoeuvres can be obtained.

The display system 2 comprises a series of commercially available L.E.D. alpha-numeric display components with appropriate on-board signal coding. For example, the display components may be DL 1416's. Such components are potentially a further source of high power consumption and so, via the port 4, the microprocessor system 5 is operable to control them so that no display segments are lit unless and until information is to be displayed and, while information is displayed, to time the duration thereof and switch the display off after a predetermined period if no use is made of the keypad in the meantime.

It will be appreciated of course that a full circuit diagram of the apparatus would include various further items known to those skilled in the art. For example, there may be needed one or more voltage regulators for the battery supply, address decoders for the address latches, clock generation circuitry preferably crystal controlled for synchronising the operation of the various components, some additional gating circuitry for properly directing the data, and delay signal generating circuitry for ensuring proper transfer of data between components. Preferably the apparatus includes also a device, e.g. an RS 8211 voltage detector, for sensing when the battery supply voltage is below a limit appropriate to proper operation of the apparatus and for indicating this fact to the flight planner.

Claims (3)

1. Apparatus comprising a first microprocessor system including first calculator means and first storage means for storing program information associated with the first calculator means and, under the control of the first calculator means, for storing data entered via said manual data entry means, and a second microprocessor system including second calculator means and second storage means for storing program information associated with the second calculator means and, under the control of the second calculator means, for storing data received from the first microprocessor system, the apparatus further comprising switch means one side of which is connected to the second microprocessor system and the other side of which is connectible, during use of the apparatus, to a power source, and the first microprocessor system being operable for receiving and temporarily storing data as it is entered via the data entry means, for determining when such data is to be transferred to the second microprocessor system, and then and only then for causing said switch means to become conductive and for transferring said temporarily stored data to the second microprocessor system.

2. Apparatus according to Claim 1, wherein said second microprocessor system includes random access memory means arranged to receive drive power other than via such switch means.

3. Portable electronic apparatus substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.

3. Portable electronic apparatus substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

New claims or amendments to claims filed on 10.1.84 Superseded claims 1 to 3.

New or amended claims:

1. Portable electronic apparatus comprising manual data entry means, a first microprocessor system including first calculator means and first storage means for storing program information associated with the first calculator means and, under the control of the first calculator means, for storing data entered via said manual data entry means, and a second microprocessor system including second calculator means and second storage means for storing program information associated with the second calculator means and, under the control of the second calculator means, for storing data received from the first microprocessor system, the apparatus further comprising switch means one side of which is connected to the second microprocessor system and the other side of which is connectible, during use of the apparatus, to a power source, and the first microprocessor system being operable for receiving and temporarily storing data as it is entered via the data entry means, for determining when such data is to be transferred to the second microprocessor system, and then and only then for causing said switch means to become conductive and for transferring said temporarily stored data to the second microprocessor system.

2. Apparatus according to Claim 1, wherein said second microprocessor system includes random access memory means arranged to receive drive power other than via said switch means.