A method for device control, comprising: obtaining remaining battery energy, a specified operating power and a timing period of the device; determining a power change line of the device indicating the relationship between the operating power and the operating time of the device based on the remaining battery energy, the specified operating power and said timing period, when the remaining battery energy is insufficient to enable the device to operate with the specified operating power for the said timing period; and adjusting an operating power of the device according to the power change line of the device to enable the device to operate for the said timing period, wherein the determining of the power change line of the device is based on the remaining battery energy, the specified operating power and the said timing period, the method further comprising: partitioning the said timing period preferably evenly into a plurality of predetermined time intervals, whereby at a start of each of the predetermined time intervals, reducing the operating power of the device by a predetermined value, and generating a first power change line indicating an operating power value within each of the predetermined time intervals; and determining the first power change line as the power change line of the device, when the energy required for operating the device for the said timing period, calculated according to the first power change line, is equal to or less than the remaining battery energy. obtaining remaining battery energy, a specified operating power and a timing period of the device; determining a power change line of the device indicating the relationship between the operating power and the operating time of the device based on the remaining battery energy, the specified operating power and said timing period, when the remaining battery energy is insufficient to enable the device to operate with the specified operating power for the said timing period; and adjusting an operating power of the device according to the power change line of the device to enable the device to operate for the said timing period, wherein the determining of the power change line of the device is based on the remaining battery energy, the specified operating power and the said timing period, the method further comprising: partitioning the said timing period preferably evenly into a plurality of predetermined time intervals, whereby at a start of each of the predetermined time intervals, reducing the operating power of the device by a predetermined value, and generating a first power change line indicating an operating power value within each of the predetermined time intervals; and determining the first power change line as the power change line of the device, when the energy required for operating the device for the said timing period, calculated according to the first power change line, is equal to or less than the remaining battery energy. partitioning the said timing period preferably evenly into a plurality of predetermined time intervals, whereby at a start of each of the predetermined time intervals, reducing the operating power of the device by a predetermined value, and generating a first power change line indicating an operating power value within each of the predetermined time intervals; and determining the first power change line as the power change line of the device, when the energy required for operating the device for the said timing period, calculated according to the first power change line, is equal to or less than the remaining battery energy.