CONSTRUCTION MACHINE
First Claim
1. A construction machine comprising:
- a swing structure;
an electric motor that drives the swing structure;
an operating device that outputs an operating signal for operating the electric motor according to an operating amount and an operating direction;
first control means that controls the electric motor based on a control signal generated based on the operating signal;
detecting means that detects an actual speed of the electric motor; and
second control means that determines whether at least one of a first condition and a second condition is satisfied, the first condition that is satisfied when a sign of a value computed by subtracting the actual speed from a target speed of the electric motor, the target speed defined by the control signal, is different from a sign of acceleration of the electric motor, and the second condition that is satisfied when a difference value between the target speed and the actual speed is greater than a first reference value and when the acceleration is greater than a second reference value.
1 Assignment
0 Petitions
Accused Products
Abstract
A construction machine includes: a swing structure (1d); an electric motor (16) that drives the swing structure; an operating device (4b) that outputs an operating signal according to an operating amount and an operating direction; an inverter device (13) that controls the electric motor based on a control signal generated based on the operating signal; a position sensor (24) that detects an actual speed of the electric motor; and a second controller (22) that determines whether at least one of a first condition and a second condition is satisfied. The first condition is satisfied when a sign of a value computed by subtracting the actual speed V from a target speed V* of the electric motor that defined by the control signal; and the second condition is satisfied when a difference between the target speed and the actual speed is greater than a reference value Vth, and when the acceleration is greater than a reference value βth. This prevents erroneous determination and failure of detection relating to determination of faults in an electronic control system from occurring.
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Citations
6 Claims
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1. A construction machine comprising:
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a swing structure; an electric motor that drives the swing structure; an operating device that outputs an operating signal for operating the electric motor according to an operating amount and an operating direction; first control means that controls the electric motor based on a control signal generated based on the operating signal; detecting means that detects an actual speed of the electric motor; and second control means that determines whether at least one of a first condition and a second condition is satisfied, the first condition that is satisfied when a sign of a value computed by subtracting the actual speed from a target speed of the electric motor, the target speed defined by the control signal, is different from a sign of acceleration of the electric motor, and the second condition that is satisfied when a difference value between the target speed and the actual speed is greater than a first reference value and when the acceleration is greater than a second reference value. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification