EP0265911A2 — Vibration control apparatus

Claim 1

Independent Claim 425 words

A vibration control apparatus comprising: state detecting means for detecting a physical value influencing characteristics of a suspension for supporting a vibrating body and for detecting a state value -representing movement of the suspension; control means comprising target control force calculating means for calculating an optimal target control force in consideration of an external force or disturbance acting on the suspension, on the' basis of the physical and state values as outputs from said state detecting means, detection control force calculating means for calculating a detection control force corresponding to the physical value detected by said state detecting means, and deviation calculating means for detecting a deviation of the detection control force from the target control force; driving means for amplifying a power of a deviation signal representing the deviation of the detection control force from the target control force and generated by said control means; and actuator means for continuously, variably controlling the suspension characteristics so as to equivalently generate a control force corresponding to the deviation of the actually detected control force from the target control force in consideration of the external force or disturbance acting on the suspension, on the basis of the power-amplified output; characterized in that said target control force calculating means in said control means is provided with: state frequency distribution calculating means for counting a frequency of occurrence obtained by counting passing or crossing of an external state signal input as the state or physical value from said state detecting means through a plurality of preset levels in every predetermined period of time in units of the preset levels to calculate a frequency distribution of the levels every predetermined period of time, and for continuously discriminating an external state according to a calculated frequency distribution; gain selecting means for selecting optimal ones of prestored gains on the basis of an output from said state frequency distribution calculating means; and optimal target control force calculating means for multiplying the gains selected by said gain selecting means with the state or physical value signal as output from said state detecting means and for adding products, wherein the frequency distribution of the state or physical value is calculated by said state frequency distribution calculating means to accurately, continuously detect a change in the external state, the optimal target control force is calculated using the gains corresponding to the change in the external state, and an optimal target control force free from an influence of a pulsed external force or disturbance component is generated, thereby continuously, optimally, variably controlling the suspension characteristics.

Claim 2

Dependent Claim 425 words

A vibration control apparatus comprising: state detecting means for detecting a physical value influencing characteristics of a suspension for supporting a vibrating body and for detecting a state value -representing movement of the suspension; control means comprising target control force calculating means for calculating an optimal target control force in consideration of an external force or disturbance acting on the suspension, on the' basis of the physical and state values as outputs from said state detecting means, detection control force calculating means for calculating a detection control force corresponding to the physical value detected by said state detecting means, and deviation calculating means for detecting a deviation of the detection control force from the target control force; driving means for amplifying a power of a deviation signal representing the deviation of the detection control force from the target control force and generated by said control means; and actuator means for continuously, variably controlling the suspension characteristics so as to equivalently generate a control force corresponding to the deviation of the actually detected control force from the target control force in consideration of the external force or disturbance acting on the suspension, on the basis of the power-amplified output; characterized in that said target control force calculating means in said control means is provided with: state frequency distribution calculating means for counting a frequency of occurrence obtained by counting passing or crossing of an external state signal input as the state or physical value from said state detecting means through a plurality of preset levels in every predetermined period of time in units of the preset levels to calculate a frequency distribution of the levels every predetermined period of time, and for continuously discriminating an external state according to a calculated frequency distribution; gain selecting means for selecting optimal ones of prestored gains on the basis of an output from said state frequency distribution calculating means; and optimal target control force calculating means for multiplying the gains selected by said gain selecting means with the state or physical value signal as output from said state detecting means and for adding products, wherein the frequency distribution of the state or physical value is calculated by said state frequency distribution calculating means to accurately, continuously detect a change in the external state, the optimal target control force is calculated using the gains corresponding to the change in the external state, and an optimal target control force free from an influence of a pulsed external force or disturbance component is generated, thereby continuously, optimally, variably controlling the suspension characteristics.

Claim 3

Dependent Claim 109 words

An apparatus according to claim 1, wherein said state frequency distribution calculating means comprises: frequency distribution calculating means for calculating the frequency of occurrence obtained by counting passing of the external state signal input as the state or physical value from said state detecting means through the plurality of preset levels and for calculating a frequency distribution of the levels every predetermined period of time; and standard deviation calculating means for calculating a standard deviation, said standard deviation calculating means being provided with means for calculating an average level width of the frequency distribution and means for comparing a deviation of the average level width from a preset value.

Claim 4

Dependent Claim 94 words

An apparatus according to claim 2, wherein said frequency distribution calculating means comprises: a plurality of parallel-connected comparing means, having different preset levels, for generating outputs, levels of which are changed when input signal levels pass or cross the preset levels; pulse generating means, connected to outputs of said plurality of comparing means, for generating pulse outputs corresponding to changes in'outputs from said plurality of comparing means; counting means, connected to said pulse generating means, for counting output pulses from said pulse generating means; and a register for storing outputs from said counting means.

Claim 5

Dependent Claim 94 words

An apparatus according to claim 2, wherein said standard deviation calculating means comprises: means for detecting a maximum frequency of occurrence in the frequency distribution and a corresponding preset level; means for calculating an average frequency in the frequency distribution; means for calculating a deviation of the maximum frequency occurrence from the preset level when the maximum frequency of occurrence as the center in the frequency distribution reaches the average frequency of occurrence; and means for comparing the deviation with the preset value to discriminate that a road is a smooth or rough road.

Claim 6

Dependent Claim 158 words

An apparatus according to claim 4, wherein said means for detecting the maximum frequency of occurrence in the frequency distribution and the corresponding preset level comprises: a first scanning circuit comprising a first multiplexer for selecting outputs from a plurality of channels of said frequency distribution calculating means, a first controller for generating a selection control signal for designating an order of selection of channels of said first multiplexer, and a first register for storing the selection control signal; a second register for storing the output from said first multiplexer; .a first comparator for comparing an output from said second register with an output from said first multiplexer, and for generating a control signal to cause the output from said first multiplexer to update contents of said second register and to cause said first register to store an output from said first controller when the output from said multiplexer is larger than the output from said second register.

Claim 7

Dependent Claim 276 words

An apparatus according to claim 5, wherein said means for calculating the deviation of the maximum frequency of occurrence from the preset level when the average frequency of occurrence reaches the maximum frequency of occurrence as the center in the frequency distribution comprises: a second scanning circuit comprising a second multiplexer for selecting the outputs of the plurality of channels of said frequency distribution calculating means, a second controller for generating a selection control signal for designating an order of selection of the channels by said second multiplexer, the selection control signal being set on the basis of the contents of said first register and being decremented every predetermined period of time, and a counter for counting the selection control signals; a third scanning circuit comprising a third multiplexer for selecting outputs of the plurality of channels of said frequency distribution calculating means, and a third controller for generating a selection control signal for designating an order of selection of the channels by said third multiplexer, the selection control signal being set on the basis of the contents of said first register and being incremented every predetermined period of time; an accumulator for accumulating outputs from said second and third multiplexers on an output from said second register in synchronism with a least significant bit signal of said third controller; and a comparator for comparing an output from said accumulator with the average frequency of occurrence calculated by said means for calculating the average frequency of occurrence of the frequency distribution, and for generating a signal for stopping said second and third scanning circuits when the output from said accumulator exceeds the average frequency of occurrence.

Claim 8

Dependent Claim 111 words

An apparatus according to claim 1, wherein said state frequency distribution calculating means and said gain selecting means in said control means comprise a microcomputer including: an input unit for receiving the output from said state detecting means; an arithmetic and logic unit for calculating the state frequency distribution on the basis of an input from said input unit, discriminating an external state on the basis of the calculated state frequency distribution, and selecting optimal gains; a memory for storing the optimal gains and a calculation algorithm of said arithmetic and logic unit; and an output unit for outputting a signal representing optimal gains selected by said arithmetic and logic unit.

Claim 9

Dependent Claim 86 words

An apparatus according to claim 1, wherein said state frequency distribution calculating means comprises: cumulative frequency distribution calculating means for accumulating previous frequency distributions obtained for a given period of time ahead of the current time, the given period of time being required for learning a change in the external state; and standard deviation calculating means for calculating an average level width of the cumulative frequency distribution, and comparing a deviation of the calculated average level width with the preset value to obtain the standard deviation.

Vibration control apparatus

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