## 3 Results
\[E_{DH}(F_{d})=3.456\cdot F_{d}^{0.0026\cdot F_{d}} \tag{10}\]  
\[E_{DS}(F_{d})=2.855\cdot F_{d}^{0.0030\cdot F_{d}} \tag{11}\]  
The study showed that the difference in energy intensity \(\Delta E\) between the DH and DS directions increases up to a contact force F\({}_{\text{d}}\) of 70 \(\pm\) 0.5 N (for a confidence level of \(p\) = 0.05). At this point, the difference is 0.75 \(\pm\) 0.21 J (for a confidence level of \(p\) = 0.05), representing a 10% reduction in energy intensity for the DS direction relative to the DH direction. Based on the course of the mathematical function models for the DH and DS directions, it was found that the greatest reduction in energy intensity of 17% occurs for a clamping force \(F_{d}\) equal to 10 \(\pm\) 0.5 N. The derived mathematical function model indicates that as \(F_{d}\) increases, the reduction in energy intensity decreases until it equalizes at the critical point (P\({}_{1}\)). Beyond this point, further increases in \(F_{d}\) lead to higher energy demand for the DS direction. This effect is shown on the individual energy intensity results for a flexible roller having 14 ribs (Figure 11) (Appendix A Table A4). The cited example of a flexible roller with 14 ribs shows that excessive deformation of the roller's ribs results in equalization of the energy required to rotate the wheel with the coupled roller of the reversing lock module in the DH and DS directions. In this specific case, this occurs at a clamping force \(F_{d}\) of approximately 115 \(\pm\) 5 N. For this value of force \(F_{d}\) for both directions of rotation, the energy intensity was 11.51 \(\pm\) 0.22 J. The concept of using rollers with inclined ribs in the reversing interlock module aimed to reduce the energy required to overcome the resistance introduced by the module when moving uphill (DS direction) while simultaneously increasing resistance when reversing (DH direction). This approach was intended to reduce the roller's downforce on the wheelchair's drive wheel, ensuring that the wheelchair remains blocked from rolling downhill on its own. However, the tests carried out showed that after the P1 point is exceeded, the opposite \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Roller Type** & **a** & **a Range** & **b** & **b Range** & **R\({}^{2}\)** & **AICC** \\ \hline E8 & 2.399 & 1.255–3.543 & 0.0035 & 0.0023–0.0047 & 0.968 & \(-\)1.789 \\ E10 & 2.729 & 2.100–3.358 & 0.0032 & 0.0025–0.0039 & 0.988 & \(-\)10.310 \\ E12 & 3.076 & 2.300–3.853 & 0.0025 & 0.0015–0.0035 & 0.960 & \(-\)12.009 \\ E14 & 3.080 & 2.486–3.674 & 0.0026 & 0.0019–0.0032 & 0.982 & \(-\)11.951 \\ E16 & 3.577 & 2.398–4.756 & 0.0022 & 0.0011–0.0034 & 0.933 & \(-\)8.172 \\ E18 & 3.586 & 2.477–4.695 & 0.0024 & 0.0014–0.0034 & 0.955 & \(-\)7.068 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of the parameters of the additional energy demand model during the propulsion of a wheelchair wheel coupled by friction with a flexible roller of the rollback prevention module. Where: \(a\) and _b_—parameters of the mathematical function model, R\({}^{2}\)—coefficient of determination, AICC—Akaike Information Criterion Corrected. situation occurs, in which rotation in the DS direction generates more energy demand than that in the DH direction. Figure 11: Graphs of the change in energy E needed to drive a wheelchair wheel coupled frictionally to a flexible roller of a reversing lock module having 14 ribs as a function of the clamping force \(F_{d}\) of the roller.