I claim:
1. A multimode cart for transporting items across a surface, comprising:
a substantially rigid and generally planar frame formed with a handle and oppositely disposed main wheels and a pivot cage therebetween;
a generally planar base assembly connected to the frame with a sliding pivot received in the pivot cage, an articulating scissor bar, and end slide couplings, the base assembly adapted to move thereby between a nested position substantially coplanar with the frame and an extended position generally orthogonal with the frame, the base assembly including an interconnection assembly disposed about the base assembly and at one end auxiliary wheels adapted to cooperate with the main wheels;
a material handling adapter releasably attached by the interconnection assembly to the cart and the adapter selected from an interchangeable group that includes a collapsible basket, a rigid basket, a handtruck adapter having a back support and a toe plate, a flat bed carrier, a nursery tray, a pallet, an assembly jig, a dunnage rack, an engine stand, a postal tray, an office mail tray, a veterinary gurney, a medical device carrier, a phlebotomy sample tray, and a dumbwaiter; and
wherein the interconnection assembly further includes a plurality of clips and attachment recesses disposed about the base assembly and adapted to releasably engage the material handling adapter.
2. A multimode cart according to claim 1, further comprising:
a capture device slidably carried by the base assembly and adapted to releasably latch to the frame when in the nested position; and
wherein the capture device further incorporates a handle at one end and an opposite latch and wherein the frame further incorporates a grapple adapted to be captured by the latch to retain the base assembly in the nested position relative to the frame.
3. A multimode cart for transporting items across a surface, comprising:
a substantially rigid and generally planar frame formed with a handle and oppositely disposed main wheels;
a generally planar base assembly connected to the frame by an articulation assembly and adapted to move between a nested position substantially coplanar with the frame and an extended position generally orthogonal with the frame, the base assembly including an interconnection assembly disposed about the base assembly and auxiliary wheels adapted to cooperate with the main wheels;
a brake assembly attached to the frame proximate to the wheels that includes at least one actuatable friction pad adapted to engage at least one of the main wheels to, when actuated, prevent rotation thereof; and
a material handling adapter releasably attached by the interconnection assembly to the cart and the handling adapter selected from an interchangeable group that includes a collapsible basket, a rigid basket, a handtruck adapter having a back support and a toe plate, a flat bed carrier, a nursery tray, a pallet, an assembly jig, a dunnage rack, an engine stand, a postal tray, an office mail tray, a veterinary gurney, a medical device carrier, a phlebotomy sample tray, and a dumbwaiter.
4. A multimode cart according to claim 3, wherein the brake assembly further includes at least one slidable brake rod attached to the frame and wherein at least one of the main wheels is formed with at least one slot adapted to receive the rod to prevent rotation of at least one of the wheels.
5. A multimode cart according to claim 3, further comprising:
a capture device slidably carried by the base assembly and adapted to releasably latch to the frame when in the nested position; and
wherein the capture device further incorporates a handle at one end and an opposite latch and wherein the frame further incorporates a grapple adapted to be captured by the latch to retain the base assembly in the nested position relative to the frame.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for performing tone detection, comprising:
receiving an input signal;
selecting a first tone format, wherein a first tone corresponds to a first symbol;
providing a first table of values corresponding to the first tone format, wherein at least one entry in the first table of values relates the first tone to the first symbol;
using a predetermined algorithm and the first table of values to determined if the input signal comprises the first symbol;
selecting a second tone format, wherein a second tone corresponds to the first symbol;
providing a second table of values corresponding to the second tone format, wherein at least one entry in the second table of values relates the second tone to the first symbol; and
using the same predetermined algorithm and the second table of values to determined if the input signal comprises the first symbol,
wherein the first tone format and the second tone format are different, and wherein the first table of values and the second table of values have at least one value that is different.
2. A method as in claim 1, wherein the first tone format is dual-tone multiple frequency (DTMF).
3. A method as in claim 1, wherein the first tone format comprises a plurality of components having overlapping frequency bands.
4. A method as in claim 1, wherein the algorithm is non-linear and does not utilize Fourier transform computations.
5. A method as in claim 1, wherein the algorithm extracts a plurality of tone components using a plurality of comb.
6. A method for detecting a tone, comprising:
receiving an input signal;
filtering the input signal so that a first finite set of selected frequencies are not allowed to pass in order to produce a first tone component;
filtering the input signal so that a second finite set of selected frequencies are not allowed to pass in order to produce a second tone component; and
using the first and second tone components to detect the tone.
7. A method as in claim 6, wherein a first comb filter having a first set of coefficients is used to perform the step of filtering the input signal so that a first finite set of selected frequencies are not allowed to pass, and wherein a second comb filter having a second set of coefficients is used to perform the step of filtering the input signal so that a second finite set of selected frequencies are not allowed to pass.
8. A method as in claim 6, wherein the first set of coefficients is adaptive and the second set of coefficients is adaptive.
9. A method as in claim 6, wherein the step of using the first and second tone components to detect the tone comprises:
estimating a frequency component of the first tone component using a first polynomial function of the first tone component; and
estimating a frequency component of the second tone component using a first polynomial function of the second tone component.
10. A method as in claim 9, wherein the step of using the first and second tone components to detect the tone further comprises:
estimating a magnitude component of the first tone component using a second polynomial function of the first tone component; and
estimating a magnitude component of the second tone component using a second polynomial function of the second tone component.
11. A method as in claim 10, wherein the step of estimating the magnitude component of the first tone component comprises:
using a moving average to extract a magnitude of the first tone component.
12. A method as in claim 9, wherein the step of estimating the frequency component of the first tone component comprises:
performing low-pass filtering using adaptive coefficients in order to reduce noise.
13. A method as in claim 6, wherein the step of using the first and second tone components to detect the tone comprises:
deciding after each sample of the input signal whether the tone has been detected, wherein samples of the input signal need not be stored.
14. A method as in claim 6, further comprising:
estimating power of the input signal using a polynomial function of the tone; and
if the power of the input signal is below a predetermined threshold, performing no further processing on the input signal until the power of the input signal is no longer below the predetermined threshold.
15. A method as in claim 6, further comprising:
adjusting gain of the input signal.
16. A method as in claim 6, wherein the input signal is dual-tone multiple frequency (DTMF) signal.
17. A method as in claim 6, wherein an amount of time required to estimate a frequency component of the first tone component is independent of a frequency of the first tone component.
18. A method as in claim 6, wherein the step of using the first and second tone components to detect the tone comprises:
using a first table for a first tone format; and
using a second table for a second tone format.
19. A method as in claim 6, further comprising:
determining if the detected tone corresponds to a valid symbol of a tone format corresponding to the detected tone.
20. A tone detector for detecting a tone, comprising:
circuitry for detecting the tone using a single algorithm, wherein the tone is provided using one of a first tone format and a second tone format; and
storage circuitry, coupled to the circuitry for detecting the tone, said storage circuitry storing one of a first tone format table and a second tone format table,
wherein the circuitry uses the single algorithm and the first tone format table when the tone is provided using the first tone format, and wherein the circuitry uses the single algorithm and the second tone format table when the tone is provided using the second tone format.
21. A tone detector as in claim 20, wherein said circuitry comprises:
a first comb filter having a first set of adaptive coefficients;
a second comb filter having a second set of adaptive coefficients; and
a self-tuning unit, coupled to the first and second comb filters, said self-tuning unit for modifying the first and second sets of adaptive coefficients.
22. A tone detector as in claim 21, wherein said circuitry further comprises:
a low-pass filter having a third set of adaptive coefficients which are modifiable by the self-tuning unit, said low-pass filter being coupled to the self-tuning unit.
23. A tone detector as in claim 20, wherein said circuitry comprises:
tone detection decision circuitry, coupled to the circuitry for detecting the tone, said tone detection decision circuitry determining if the detected tone corresponds to a valid symbol of the first tone format when the tone is provided using the first tone format and determining if the detected tone corresponds to a valid symbol of the second tone format when the tone is provided using the second tone format.