Method for detecting slip in a belt driven integrated starter system

A method for detecting belt slip in a starter system for starting an internal combustion engine of a motor vehicle, the starter system comprising a belt-driven integrated starter generator, the method comprising

• evaluating, via a control unit of the motor vehicle, a belt slip when a determined belt slip value exceeds a limit value,
• wherein the determined belt slip value is determined to belong to a defined time window T, the defined time window T opens after a start of the internal combustion engine, and
• the determined belt slip value takes into account at least one change in velocity over time value of the belt-driven integrated starter generator within the defined time window T,
• the defined time window T is set for slip detection after a start of the internal combustion engine, and the control unit repeats at least:
• determining the at least one change in velocity over time value of the belt-driven integrated starter generator;
• determining a slip number assigned to the respective determined change in velocity over time value;
• adding up the slip numbers determined so far to a resulting belt slip value;
• and
• comparing the determined belt slip value with the limit value until a determined belt slip value exceeds the limit value or the defined time window T is exceeded.

A method for detecting belt slip in a starter system for starting an internal combustion engine of a motor vehicle, the starter system comprising a belt-driven integrated starter generator, the method comprising

• evaluating, via a control unit of the motor vehicle, a belt slip when a determined belt slip value exceeds a limit value,
• wherein the determined belt slip value is determined to belong to a defined time window T, the defined time window T opens after a start of the internal combustion engine, and
• the determined belt slip value takes into account at least one change in velocity over time value of the belt-driven integrated starter generator within the defined time window T,
• the defined time window T is set for slip detection after a start of the internal combustion engine, and the control unit repeats at least:
• determining the at least one change in velocity over time value of the belt-driven integrated starter generator;
• determining a slip number assigned to the respective determined change in velocity over time value;
• adding up the slip numbers determined so far to a resulting belt slip value;
• and
• comparing the determined belt slip value with the limit value until a determined belt slip value exceeds the limit value or the defined time window T is exceeded,
• the at least one change in velocity over time value of the belt-driven integrated starter generator is determined by measuring a first speed value RPM_a within the defined time window T and measuring a second speed value RPM_b after an expiration of a defined time sampling interval Ti_Sample, the first speed value RPM_a and the second speed value RPM_b are measured based on a shaft speed of the belt-driven integrated starter generator, wherein the respective determined change in velocity over time value of the belt-driven integrated starter generator is calculated by an equation:
• (RPM_a−RPM_b)/Ti_Sample.