US 9,753,437 B2Granted

Safety device and computation method for safety device

AssigneeMitsubishi Heavy Industries, Ltd.

InventorsKiyoshi Ishii, Masanobu Soga, Hideaki Emoto, Shinichi Toda, Katsuya Daigo, Kenichi Morimoto

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Abstract

A safety device includes a first computation unit, a second computation unit, an output control unit, and a first central processing device. The first computation unit is configured to perform a first computation on a detected value detected from a subject to be controlled, thus obtaining a first result value. The second computation unit is configured to perform a second computation on the detected value, thus obtaining a second result value which is to be determined if equal to the first result value. The output control unit is configured to output the first result value in a case that the second computation unit determines that the first result value is equal to the second result value, and not to output the first result value in a case that the second computation unit determines that the first result value is not equal to the second result value.

Claims7

Dependent claims

A safety device comprising:

a first computation unit configured to perform a first computation on a detected value that is detected from a subject to be controlled, thus obtaining a first result value;
a second computation unit configured to perform a second computation on the detected value, thus obtaining a second result value, and determine whether the first result value is equal to the second result value;
an output control unit configured to output the first result value in a case that the second computation unit determines that the first result value is equal to the second result value, the output control unit being configured not to output the first result value in a case that the second computation unit determines that the first result value is not equal to the second result value;
and
a first central processing device including the first computation unit and the second computation unit,
wherein the first computation is a logical computation and the second computation is a floating point computation, or the second computation is a logical computation and the first computation is a floating point computation,
wherein if the first computation is the logical computation and the second computation is the floating point computation, the first computation unit is configured to perform the logical computation and the second computation unit is configured to perform the floating point computation, thus emulating the logical computation, and if the second computation is the logical computation and the first computation is the floating point computation, the first computation unit is configured to perform the floating point computation and the second computation unit is configured to perform an integer computation by emulation, and
wherein the first computation unit is different from the second computation unit.

5 more elements

A computation method for a safety device, the computation method comprising:

a step of performing a first computation on a detected value that is detected from a subject to be controlled, thus obtaining a first result value;
a step of performing a second computation on the detected value, thus obtaining a second result value;
a step of determining whether the first result value is equal to the second result value;
and
a step of outputting the first result value in a case that it is determined that the first result value is equal to the second result value, and not outputting the first result value in a case that it is determined that the first result value is not equal to the second result value,
wherein the first computation is a logical computation and the second computation is a floating point computation, or the second computation is a logical computation and the first computation is a floating point computation, and
wherein if the first computation is the logical computation and the second computation is the floating point computation, the step of performing the first computation unit comprises a step of performing the logical computation on the detected value, and the step of performing the second computation comprises a step of performing the floating point computation on the detected value, thus emulating the logical computation, and if the second computation is the logical computation and the first computation is the floating point computation, the step of performing the first computation comprises a step of performing the floating point computation, and the step of performing the second computation comprises a step of performing an integer computation by emulation.

4 more elements

Dependencies are inferred from the claim text.