A system for monitoring the state of a cable, which is guided in an energy chain between a base and a movable driver element. The movable energy chain forms a movable run at a driver element, a resting run at a base and, between the two runs, a deflecting bend. A monitoring device having at least one indicating element at the energy chain evaluates an indicating-element signal and monitors whether an error state occurs. The indicating element has two electrical indicating conductors guided by the energy chain, which indicating conductors extend along the movable run, and the monitoring device comprises a measuring circuit for resistance measurement or conductance measurement. One end point of each indicating conductor is connected to the measuring circuit and the other end points of the indicating conductors are short circuited such that the indicating conductors form a measurement loop.

A power tool is provided including a housing, a brushless direct-current (BLDC) electric motor disposed inside the housing, power switches disposed between a power supply and the electric motor and including high-side switches and low-side switches, and a control unit configured to control a switching operation of the power switches to operate the electric motor and electronically brake the motor by simultaneously activating the high-side switches or the low-side switches to stop the rotation of the motor upon detection of a condition prompting the braking of the motor. The control unit is configured to detect the condition that prompts the braking of the electric motor, set a braking profile for braking the electric motor based on the detected condition, and execute braking of the electric motor using the braking profile.

A power tool is provided including a housing, a brushless direct-current (BLDC) electric motor disposed inside the housing, power switches disposed between a power supply and the electric motor and including high-side switches and low-side switches, and a control unit configured to control a switching operation of the power switches to operate the electric motor and electronically brake the motor by simultaneously activating the high-side switches or the low-side switches to stop the rotation of the motor upon detection of a condition prompting the braking of the motor. The control unit is configured to detect the condition that prompts the braking of the electric motor, set a braking profile for braking the electric motor based on the detected condition, and execute braking of the electric motor using the braking profile.

The safety system for a machine (1), provided with a blade (12), comprises: means (2) for detecting a dangerous condition for the safety of an operator; and a cutting-off apparatus (2) adapted to cut off the blade (12), following the detection of the dangerous condition.

A collision stress releasing device reversely rotates a feed motor by a return amount set in a return amount setter based on a contact position of a movement unit or a collision detection position regarded as a contact position. Generally, a large error does not occur even when the collision detection position is regarded as the contact position, but when the movement unit or the colliding member has low rigidity, a control of setting a return amount in response to the speed of the movement unit or a control of estimating an actual contact position from a rise curve of a load after a collision is more desirable.

A collision stress releasing device reversely rotates a feed motor by a return amount set in a return amount setter based on a contact position of a movement unit or a collision detection position regarded as a contact position. Generally, a large error does not occur even when the collision detection position is regarded as the contact position, but when the movement unit or the colliding member has low rigidity, a control of setting a return amount in response to the speed of the movement unit or a control of estimating an actual contact position from a rise curve of a load after a collision is more desirable.

The present invention provides a collision prevention control system based on an electric lifting table and a collision prevention method thereof. The collision prevention control system includes a lifting table, an electronic lifting table control box disposed on the lifting table, and a single-chip microcomputer disposed in the electric lifting table control box. The electric lifting table control box is internally provided with an acceleration and gyroscope chip, the acceleration and gyroscope chip performing synchronous motion with the lifting table, the acceleration and gyroscope chip being in information interaction with the single-chip microcomputer, and motion control on the lifting table being performed through the single-chip microcomputer. The present invention has the advantageous effects as follows: the system has higher sensitivity and more reliable operation, and senses a slight angular change or an acceleration change when the lifting table encounters resistance.

A power tool is provided including a housing, a brushless direct-current (BLDC) electric motor disposed inside the housing, power switches disposed between a power supply and the electric motor and including high-side switches and low-side switches, and a control unit configured to control a switching operation of the power switches to operate the electric motor and electronically brake the motor by simultaneously activating the high-side switches or the low-side switches to stop the rotation of the motor upon detection of a condition prompting the braking of the motor. The control unit is configured to detect the condition that prompts the braking of the electric motor, set a braking profile for braking the electric motor based on the detected condition, and execute braking of the electric motor using the braking profile.

A power tool is provided including a housing, a brushless direct-current (BLDC) electric motor disposed inside the housing, power switches disposed between a power supply and the electric motor and including high-side switches and low-side switches, and a control unit configured to control a switching operation of the power switches to operate the electric motor and electronically brake the motor by simultaneously activating the high-side switches or the low-side switches to stop the rotation of the motor upon detection of a condition prompting the braking of the motor. The control unit is configured to detect the condition that prompts the braking of the electric motor, set a braking profile for braking the electric motor based on the detected condition, and execute braking of the electric motor using the braking profile.

A power tool and a detection method for the power tool. The detection method includes collecting acceleration data, via use of an acceleration sensor of the power tool, along a tangential direction of a rotation axis of a working portion of the power tool, determining whether a proportion of the collected acceleration data that exceeds a first acceleration threshold in a preset time window exceeds a preset value, and determining that a kickback occurs in the power tool when the proportion exceeds the preset value.