Estimation of Clamp Force in Brake-by-Wire Systems: A Step-by-Step Identification Approach

IEEE Trans. Veh. Technol.

Rocco³

2008

In brake-by-wire systems, central controllers require accurate information about the clamp force between the brake pad and the disc as a function of pad displacement, which is usually denoted as the characteristic curve of the caliper. Due to aging, temperature, and other environmental variations, caliper characteristic curves vary with time. Therefore, automatic caliper calibration in real-time is vital for high-performance braking action and vehicle safety. Due to memory and processing-power limitations, the calibration technique should be memory efficient and of low computational complexity. In a typical electromechanicalbraking-system design, clamp force measurement variations with actuator displacement is hysteretic. This paper introduces a simple and memory-efficient real-time calibration technique in which a clamp-force model is fitted to the data samples around each hysteresis cycle. The model includes a Maxwell-slip model for the hysteresis caused by friction. Experimental results from the data recorded in various temperatures show that the proposed technique results in clamp force measurements with less than 0.7% error over the range of clamp-force variations. It is also shown that, by using these measurements, the characteristic curve can be accurately calibrated in real-time.

Section: Characteristic-curve Calibration: Algorithmmentioning

confidence: 99%

Real-Time Clamp Force Measurement in Electromechanical Brake Calipers

IEEE Trans. Veh. Technol.

Rocco³

2008

“…Applying the defined form of (8) to a new uniform random data set yields a root-mean-square error (rmse) of 0.28 kN. This error is attributed to the model structure of (8), being not entirely representative [19], as well as the sensory-noise effects. Fig.…”

Section: B Compensationmentioning

confidence: 99%

Clamp-Force Estimation for a Brake-by-Wire System: A Sensor-Fusion Approach

Saric

IEEE Trans. Veh. Technol.

2008

The elimination of a clamp-force sensor from brake-by-wire system designs is strongly demanded due to implementation difficulties and cost issues. In this paper, a new method is presented to estimate the clamp force based on other sensory information. This estimator fuses the outputs of two models to optimize the root-mean-square error (RMSE) of estimation. Experimental results show that the estimator can accurately track the true clamp force for high-speed cases as demanded by the antilock braking system controls. A training strategy has been used to ensure that the estimator can successfully adapt to parameter variations associated with wear. This paper is concluded with a discussion on the reliability of the developed clamp-force estimator.

“…Hoseinnezhad et al [7] found that the use of a characteristic curve to estimate clamp force for dynamic scenarios is inaccurate due to the dynamic behaviour of the caliper. The cause of this effect is attributed to the viscoelastic behaviour exhibited mainly by the aluminium caliper bridge [8] and to some degree the brake pads [9].…”

Section: Developmental Backgroundmentioning

confidence: 99%

“…The cause of this effect is attributed to the viscoelastic behaviour exhibited mainly by the aluminium caliper bridge [8] and to some degree the brake pads [9]. To accommodate for this, Hoseinnezhad et al [7] developed a dynamic clamp force estimator that solely relied on position measurements from a resolver. This model is shown in discrete time notation as follows:…”

Section: Developmental Backgroundmentioning

confidence: 99%

See 1 more Smart Citation

A Sensor Fusion Approach to Estimate Clamp Force in Brake-by-Wire Systems

Saric

2006 IEEE 63rd Vehicular Technology Conference

Elimination of a clamp force sensor from brake-bywire system designs is strongly demanded due to implementation difficulties and cost issues. In this paper a new method is presented to estimate clamp force based on other sensory information. The proposed estimator fuses the outputs of two models to optimise the root mean square error (RMSE) of estimation. Experimental results show that the estimator can accurately track the true clamp force for high speed cases as demanded by anti-lock braking system (ABS) controls. A training strategy has been used to ensure that the estimator can successfully adapt to frictional variations within the reduction gearing. This paper is concluded with a discussion on the reliability of the developed clamp force estimator.