{
  "$type": "site.standard.document",
  "description": "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…",
  "path": "/patents/976226",
  "publishedAt": "2014-04-16T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "E02F9/128",
    "HITACHI CONSTRUCTION MACHINERY [JP]"
  ],
  "textContent": "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 ²th. This prevents erroneous determination and failure of detection relating to determination of faults in an electronic control system from occurring.",
  "title": "CONSTRUCTION MACHINE"
}