초록 ▼

A failsafe system for an engine-control servomotor compares a servomotor command signal to a feedback signal from the servomotor. When the magnitude of the difference between the two signals is greater than a predetermined value for a predetermined time, the failsafe system shuts down the servomotor

A failsafe system for an engine-control servomotor compares a servomotor command signal to a feedback signal from the servomotor. When the magnitude of the difference between the two signals is greater than a predetermined value for a predetermined time, the failsafe system shuts down the servomotor or performs some other engine shut-down procedure. The failsafe system includes a comparator for comparing the two signals, the output of which leads to two other op-amp-type comparators connected in parallel, which work on negative or positive outputs of the first-mentioned comparator, respectively. Each of the later comparators receives a reference voltage input against which to compare the output of the first-mentioned comparator. Their outputs lead parallelly to time-delay circuits which check for a positive output for a predetermined length of time by a well-known capacitor-integration technique.

대표청구항 ▼

A failsafe system for producing a command signal for controlling a controlled device of an engine comprising: (a) means for generating a feedback signal indicative of the state of said controlled device; (b) a controller for controlling the state of said controlled device whereby an absolute differe

A failsafe system for producing a command signal for controlling a controlled device of an engine comprising: (a) means for generating a feedback signal indicative of the state of said controlled device; (b) a controller for controlling the state of said controlled device whereby an absolute difference in magnitude between said feedback signal and said command signal is within a predetermined range; (c) a malfunction determining means comprising a first circuit including a first comparator for comparing a difference between said command signal and said feedback signal with a first predetermined level and for generating a first output when said command signal is greater than said feedback signal and said difference exceeds the first predetermined level, a first integrator for integrating the first output from said first comparator, and a second comparator for comparing the output of said integrator with a second predetermined level to generate a malfunction signal when the output of said first integrator exceeds the second predetermined level; and wherein said malfunction determining means further comprises a second circuit including a third comparator for comparing a difference between said command signal and said feedback signal with the first predetermined level and for generating a second output when said command signal is smaller than said feedback signal and said difference exceeds the first predetermined level, a second integrator for integrating the second output, and a fourth comparator for comparing the output of said second integrator with the second predetermined level to generate a malfunction signal when the output of said second integrator exceeds the second predetermined level.