Influencing driver chosen cornering speed by means of modified steering feel

Figures & data

Figure 1. Roll Stability Advisor (RAS) presented by Winkler et al.[10] showing current lateral acceleration and rollover threshold.

Figure 2. Schematic illustration of the active steering system with superposition of torque in a heavy truck for manipulation of steering feel.

Figure 3. General conception of the presented MSF characteristics for rollover indication in a heavy truck expressed as added steering wheel torque as a function of lateral acceleration.

Figure 4. Matlab Simulink model of MSF functionality for rollover indication.

Figure 5. Active steering functionality in a software-in-the-loop environment.

Figure 6. Rollover indication characteristic showing the added steering wheel torque over lateral acceleration presented for Setting 1. The intervention begins at a_y=1.6 m/s² and is limited to M_{add, max}=8 N m.

Table 1.  Test vehicle properties.

Manufacturer	Scania
Type	R730
Axle configuration	4×2
Wheelbase	3.7 m
Total weight	15.1 t
Axle load distribution	51% front; 49% rear
Active steering	Electric torque overlay (in addition to HPS)

Figure 7. Example plots for two drivers for possible drift detection in mean acceleration over the driver's laps. Every line represents a certain bend: (a) smooth driving and (b) uneven driving.

Figure 8. Example plots for two drivers for possible drift detection in maximum acceleration over the driver's laps. Every line represents a certain bend: (a) smooth driving and (b) uneven driving.

Figure 9. Setting 1 kernel density estimation and its reference calculated from the histogram data (10 curves, all drivers). The significance statement origins from Table 2: (a) absolute lateral acceleration: AVERAGES. (b) Absolute lateral acceleration: MAXIMA.

Table 2.  Significance for tests on different populations, each setting against its reference taking the samples>1.7 m/s² into consideration (p-value).

	Maxima		Averages
Ref. vs.	Setting 1	Setting 2	Setting 1	Setting 2
F-test	p=0.08%	p=61.0%	p=4.72%	p=78.5%
t-Test	p=0.84%	p=50.1%	p=43.5%	p=86.1%
U-test	p=5.38%	p=30.0%	p=89.2%	p=56.3%
KS-test	p=1.59%	p=33.5%	p=84.0%	p=77.3%

Figure 10. Setting 2 kernel density estimation and its reference calculated from the histogram data (10 curves, all drivers). The significance statement origins from Table 2: (a) absolute lateral acceleration: AVERAGES. (b) Absolute lateral acceleration: MAXIMA.

Table 3.  Complement to Table 2: significance for tests on different populations over full a_y-range.

	Maxima		Averages
Ref. vs.	Setting 1	Setting 2	Setting 1	Setting 2
F-test	p=0.47%	p=69.3%	p=3.97%	p=19.7%
t-Test	p=7.69%	p=99.8%	p=27.4%	p=86.8%
U-test	p=31.9%	p=86.0%	p=60.4%	p=99.4%
KS-test	p=7.52%	p=87.8%	p=73.2%	p=91.3%

Table 4.  Mean differences to reference in maximum and averaged lateral acceleration in each bend.

	Maxima		Averages
Bend	Setting 1	Setting 2	Setting 1	Setting 2
1	2.42%	−2.04%	2.19%	−2.59%
2	4.78%	1.56%	4.81%	0.85%
3	6.13%	0.63%	3.22%	−1.72%
4	2.86%	3.48%	3.31%	2.24%
5	1.15%	−0.54%	3.13%	−0.84%
6	3.00%	−3.15%	2.83%	−2.26%
7	1.09%	0.21%	−0.86%	−0.30%
8	2.40%	−3.50%	1.15%	−2.49%
9	3.29%	−0.58%	2.19%	−0.04%
10	4.45%	2.48%	2.70%	2.57%
Mean	3.16%	−0.15%	2.47%	−0.46%

Figure 11. Differences of maximum lateral acceleration with confidence intervals over bends: (a) Setting 1 against its reference. (b) Setting 2 against its reference.

Winkler C, Fancher P, Ervin R. Intelligent systems for aiding the truck driver in vehicle control. SAE technical paper series, reprinted from: IV: vehicle navigation systems and advanced controls (SAE 1999-01-1301); 1999.

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