Method and device for determining a speed by means of an inductive speed sensor

A speed measurement device for determining a speed in a vehicle using a measurement sensor, which includes at least one coil and a ferromagnetic transmitter element, by changing the inductance of the at least one coil and the voltage induced in the at least one coil, comprising:

• at least one inductive speed sensor, including:
• the at least one coil;
• the ferromagnetic transmitter element;
• and
• an evaluation circuit;
• wherein the evaluation circuit is configured to record a change in the inductance of the at least one coil and to determine the speed based on the changed inductance of the at least one coil,
• wherein the evaluation circuit is further configured to perform the following:
• recording the change in the inductance of the at least one coil, and determining the speed based on the changed inductance of the at least one coil only until the determined speed has reached a speed limit value starting from lower speeds,
• recording a change in the voltage induced in the at least one coil when the determined speed has exceeded the speed limit value starting from lower speeds, and determining the speed based on the changed voltage, and
• recording a change in the inductance of the at least one coil when the determined speed has reached or dropped below the speed limit value starting from higher speeds, and determining the speed based on the changed inductance of the at least one coil.

A driver assistance system, comprising:

• at least one speed measurement device for determining a speed in a vehicle using a measurement sensor, which includes at least one coil and a ferromagnetic transmitter element, by changing the inductance of the at least one coil and the voltage induced in the at least one coil, including:
• at least one inductive speed sensor, including:
• the at least one coil;
• the ferromagnetic transmitter element;
• and
• an evaluation circuit;
• wherein the evaluation circuit is configured to record a change in the inductance of the at least one coil and to determine the speed based on the changed inductance of the at least one coil,
• wherein the evaluation circuit is further configured to perform the following:
• recording the change in the inductance of the at least one coil, and determining the speed based on the changed inductance of the at least one coil only until the determined speed has reached a speed limit value starting from lower speeds,
• recording a change in the voltage induced in the at least one coil when the determined speed has exceeded the speed limit value starting from lower speeds, and determining the speed based on the changed voltage, and
• recording a change in the inductance of the at least one coil when the determined speed has reached or dropped below the speed limit value starting from higher speeds, and determining the speed based on the changed inductance of the at least one coil.

A vehicle, comprising:

• a driver assistance system, including:
• at least one speed measurement device for determining a speed in a vehicle using a measurement sensor, which includes at least one coil and a ferromagnetic transmitter element, by changing the inductance of the at least one coil and the voltage induced in the at least one coil, including:
• at least one inductive speed sensor, including:
• the at least one coil;
• the ferromagnetic transmitter element;
• and
• an evaluation circuit;
• wherein the evaluation circuit is configured to record a change in the inductance of the at least one coil and to determine the speed based on the changed inductance of the at least one coil,
• wherein the evaluation circuit is further configured to perform the following:
• recording the change in the inductance of the at least one coil, and determining the speed based on the changed inductance of the at least one coil only until the determined speed has reached a speed limit value starting from lower speeds,
• recording a change in the voltage induced in the at least one coil when the determined speed has exceeded the speed limit value starting from lower speeds, and determining the speed based on the changed voltage, and
• recording a change in the inductance of the at least one coil when the determined speed has reached or dropped below the speed limit value starting from higher speeds, and determining the speed based on the changed inductance of the at least one coil.