Output stage control in the event of a fault
A method for implementing a transition from a functioning steering assistance system to a deactivated steering assistance system when a fault occurs, comprising the following steps: establishing the fault of the steering assistance system; establishing that all high-side power switches are functional (first case), or establishing that all low-side power switches are functional (second case); and in the first case: opening all high-side power switches and performing PWM-like control of the low-side power switches; or in the second case: opening all low-side power switches and performing PWM-like control of the high-side power switches.
1. A method for implementing a peakless transition in required manual torque when transitioning, due to a fault, from a functioning steering assistance system to a deactivated steering assistance system, comprising the following steps:
establishing the fault of the steering assistance system;
while occurrence of said fault is established, establishing that all high-side power switches are functional (first case) or establishing that all low-side power switches are functional (second case); and
while occurrence of said fault is established, dissipating energy from a driving motor of the steering assistance system to achieve a smooth transition without peaks in required manual torque to transition from said functioning steering assistance system to said deactivated steering system by in the first case: opening all high-side power switches and performing PWM-like control of the low-side power switches; or in the second case: opening all low-side power switches and performing PWM-like control of the high-side power switches.
2. The method according to claim 1 , wherein, in the first case, not all low-side power switches, and in the second case not all high-side power switches, are controlled in a PWM-like manner, but in each case one or more power switches is continuously turned on.
3. A steering system comprising a control unit for a vehicle, wherein the control unit comprises a memory means having a computer program stored thereon, the computer program being configured to carry out the method according to claim 1 .
4. A non-transitory computer-readable storage medium that stores program code means which upon execution by a computer performs the steps for implementing a peakless transition in required manual torque when transitioning, due to a fault, from a functioning steering assistance system to a deactivated steering assistance system, comprising:
establishing the fault of the steering assistance system;
while occurrence of said fault is established, establishing that all high-side power switches are functional (first case) or establishing that all low-side power switches are functional (second case); and
while occurrence of said fault is established, dissipating energy from a driving motor of the steering assistance system to achieve a smooth transition without peaks in required manual torque to transition from said functioning steering assistance system to said deactivated steering system by in the first case: opening all high-side power switches and performing PWM-like control of the low-side power switches; or in the second case: opening all low-side power switches and performing PWM-like control of the high-side power switches.
5. A steering system comprising a control unit for a vehicle, wherein the control unit comprises a memory means having a computer program stored thereon, the computer program being configured to carry out the method according to claim 2 .
6. A non-transitory computer-readable storage medium that stores program code means which upon execution by a computer performs the steps for implementing a peakless transition in required manual torque when transitioning, due to a fault, from a functioning steering assistance system to a deactivated steering assistance system, comprising:
establishing the fault of the steering assistance system;
while occurrence of said fault is established, establishing that all high-side power switches are functional (first case) or establishing that all low-side power switches are functional (second case); and
while occurrence of said fault is established, dissipating energy from a driving motor of the steering assistance system to achieve a smooth transition without peaks in required manual torque to transition from said functioning steering assistance system to said deactivated steering system by in the first case: opening all high-side power switches and performing PWM-like control of the low-side power switches; or in the second case: opening all low-side power switches and performing PWM-like control of the high-side power switches; and
wherein, in the first case, not all low-side power switches, and in the second case not all high-side power switches, are controlled in a PWM-like manner, but in each case one or more power switches is continuously turned on.